LIFE+ Project Number LIFE07 ENV/UK/ GRACC. FINAL Report Covering the project activities from 01/01/2009 to 31/12/2011. Reporting Date 01/01/2012

Transcription

1 LIFE+ Project Number LIFE07 ENV/UK/ GRACC FINAL Report Covering the project activities from 01/01/2009 to 31/12/2011 Reporting Date 01/01/2012 LIFE+ PROJECT NAME or Acronym Green Roofs Against Climate Change (GRACC) also known as The Green Roof Code and Guidance

2 Data Project Project location: UK wide Project start date: 01/01/2009 Project end date: 31/12/2011 Total Project duration (in months): 36 months Total budget: 914,213 EC contribution: 266,863 (%) of total costs: 49.76% (%) of eligible costs: 49.87% Data Beneficiary Name Beneficiary: Groundwork Sheffield Contact person: Miss Anna Cooper Postal address: The Innovation Centre, 217 Portobello, Sheffield, S1 4DP Visit address: The Innovation Centre, 217 Portobello, Sheffield, S1 4DP Telephone: Fax: Website:

3 1. List of content 2. Executive summary 3. Introduction 4. Administrative part 4.1 Description of management system a) Stakeholder mapping b) Awareness raising and consultation c) Final production and dissemination d) Project planning 4.2 Evaluation of management system a) The process b) Project Management, problems, partnerships and their added value c) Technical and commercial application d) Comparison against project objectives e) Effectiveness of dissemination activities f) The future continuation of the project and remaining threats 5. Technical part 5.1 Task by task - description 5.2 Evaluation 5.3 Analysis of long term benefits 1. Environmental benefits a) Direct / quantitative environmental benefits ii) LIFE+ Environmental policy and Governance b) Relevance for environmentally significant issues or policy areas 2. Long term sustainability a) Long term/qualitative environmental benefits ii) LIFE+ environmental policy and governance b) Long term qualitative economic benefits c) Long term qualitative social benefits 3. Replicability, demonstration, transferability and cooperation 4. Innovation and demonstration value 5. Long term indicators of project success 5.4 Dissemination issues Dissemination issues: overview per activity layman s report After-LIFE communication plan Appendices A - Project GANTT chart B - Stakeholder map GRACC C - Tasks completed by team D - Habitat Action Plan E - Supplementary planning F - Mapping excercise G - Stuttgart visit write-up H - Awareness raising activities I - Green Roof Guide J - DIY Guide to green roofs K - Case studies L - Life consultation press release M - Project launch press release N - Judging panel for NFRC 2010 O - Local authorities consulted P - Example article Q - Organigramme R - Overview and evaluation S - Management structure T - Developer s Guide U - NFRC Awards press release V - GRO meeting agenda W - Attendees to GRO event X - Glossary of terms Y - GRO specialist groups Z - Code presentation

4 2. Executive Summary The project In 2009 Groundwork Sheffield secured 457,206 of European LIFE+ funding to deliver the project Green Roofs against Climate Change (GRACC). The project s main aim was to create a green roof code of best practice; setting standards for the design, installation and maintenance of green roofs across the UK. LIFE+ is the EU s funding stream for supporting environmental policy development across Member States. It is generally accepted that climate change is happening - focusing attention on the need to plan and adapt urban environments for changing future climates. This has resulted in new forms of urban design, notably the integration of landscape with buildings to bring about a naturally cooler and more climatically responsive built environment. Green roofs are considered part of this innovative sustainable building form. Impermeable rooftops account for over 35% of space in urban areas illustrating the scope there is to implement green roof technology. Green roofs can help to reduce the effect of climate change and form part of the adaptation solution to storm-water overflow, flooding, high energy consumption, and increase in the production of greenhouse gases, the spread of non porous groundcover and the Urban Heat Island Effect, whist creating affective wildlife habitat. However, green roofs can only provide these environmental benefits if designed and installed in a way that ensures that minimum performance criteria are met. The project objectives were to address climate change by increasing the quality of green roofs in the UK by working with key stakeholders to produce a document or Code to support anyone who is considering, designing, specifying, installing or maintaining a green roof, or those involved in the strategic planning of green infrastructure. There is no current UK guidelines relating to this in the UK but there is in other countries such as Germany, which has increased confidence in the technology. Therefore the underlying hypothesis for the project was that without The Code, confidence in the technology, due to green roofs not meeting their potential, and so the opportunity would be lost for green roofs to become a mainstream form of urban design in UK towns and cities. The use of principles of The Code improves the quality of green roof installation and design having a positive impact on the following climate change issues: Flooding - Green roofs reduce storm flow run-off by holding water in the green roof system. Increasing production of greenhouse gases - Green roofs help maintain cooler buildings reducing the need for artificial cooling in buildings. This in turn reduces the buildings electricity consumption and CO2 emissions. The Urban Heat Island Effect - Green roofs help to maintain cooler urban environments resulting in cooler towns and cities. The main project objectives were as follows: 1. To address climate change by increasing the quality of green roofs 2. To work with the European Federation of Green Buildings to support the development of a pan European green roof standard 3. To develop a supplementary planning document to be used by local authorities in order to influence the planning framework 4. To disseminate knowledge and experience regarding the use of the UK Code and of green roofs more generally via Groundwork Sheffield and Livingroofs.org. 5. To identify and provide solutions to potential barriers to uptake, including the technical and economic viability for large scale introduction 6. To encourage stakeholders to adopt The Code through an Innovation Awards scheme that will recognise inspirational approaches to roof greening combined with other sustainable features e.g. photovoltaic s and Sustainable Urban Drainage (SUDs) These objectives would be addressed by the following actions: Establishing a UK code of best practice for green roofs, together with associated standards and guidance with final adoption in 2011 Reporting regularly to the EBF in order to disseminate best practice for the development of the Pan European Standard. Facilitating two events with ISU (Sweden) for information sharing and exchange of best practice in 2009 &

5 Working with 10 Local Authorities/public agencies to implement supplementary planning guidance on green roofs Developing a library of 30 case-studies (25 on award winners) that demonstrates the benefits of green roofs for meeting environmental and biodiversity targets. Delivering 36 awareness-raising events on The Code Establishing a dedicated webpage Producing and disseminating quarterly e-bulletins on developments and progress within green roof technology. Making 25 green roof awards over the project lifetime Producing 3 guidance notes including a supplementary planning document All of these deliverables were met or exceeded except for the number of case studies and awards due to partnering with the NRFC to create a green roof award in their annual awards ceremony. Key stakeholders engaged with the project included The Green Roof Centre, University of Sheffield, Livingroofs.org, GRO (Green Roof Organisation), Environment Agency and Homes and Communities Agency. A glossary of terms can be found in appendix Y. Consultation with stakeholders highlighted the need for not one but two documents: The Green Roof Code - a technical manual for green roof installers The Green Roof Guide - an interactive web based guide which was outcome focused and designed for people commissioning green roofs All parties using this Guide who require technical information should have a copy of the GRO Code: www. greenroofcode.co.uk and the most recent version of the FLL Guidelines. Complementary documents such as a set of green roof guidance notes, green roof habitat plan, developers guide to green roofs and a supplementary planning document were produced to help integrate green roofs into the planning framework and address barriers to the uptake of green roofs. The Code was published by edited and published and edited by Groundwork Sheffield ( org.uk/sheffield), (ISBN: ). It meets the criteria of relevant complementary documentation including the following building Regulations (building design, structural design and maintenance), Health and Safety and many British Standards relating to Mastic asphalt and bitumen waterproofing specifications. The project team consisted of Project Manager, Dissemination and Network Manager, Green Roof Development Officer, Monitoring Officer, Administration Officer and Expert Advisor. Methodology and dissemination The methodology applied to this project was simple in structure and is replicable in other areas. First the project stakeholders have to be identified and engaged. Then desk based research occurred into the various codes and guidance currently available in the industry. Focus groups and awareness raising events input into this and the key principles The Code would encompass. An example of a presentation delivered can be found in appendix Z. Stakeholders were then asked to consult on the drafted Code document. This was then disseminated through various dissemination and awareness raising activities throughout the project. A series of specialist technical groups (technical, vegetation and regulatory view in appendix Y) were created to provide specific advise on The Code and 2 Expert Advisors were brought onboard (Beta Technology and The University of Sheffield s green roof expert Jeff Sorrill) to help consultation activities. They helped to research existing codes of best practice. Key stakeholders were identified included; Government Bodies (Environment Agency, The Institute of Structural Engineers, Homes and Communities Agency, Natural England) The green roof industry (manufacturers, installers, supply chain companies) Local Authorities (planners, biodiversity officers, building control) Built environment professionals (architects, structural engineers, surveyors) 5

6 Outputs Achieved The awareness raising, consultation and dissemination phase involved the delivery of the following outputs: 7 workshops 5 focus groups 36 awareness raising events Engagement of 2,537 participants Engagement of 183 local authorities and 565 local authority personnel (See appendix O) Consultation of 165 stakeholders 4 task groups 1 joint best practice exchange with European partners Production of 7 case studies Delivery of 4 green roof awards Feature of 11 editorials in key construction press and local media Press releases to local media Creation of dedicated webpage s The Code and Green Roof Guide The project team delivered seminars at key industry events such as Ecobuild (London) which attracts over 40,000 visitors annually and Greenbuild Expo (Manchester. An online portal was use to get feedback on The Code from stakeholders. These events helped to establish the key principles of The Code and the format it would take. Jeff Sorrill, expert advisor, speaking at EcoBuild - Earls Court, London An online portal (similar to that used by Local Authorities on feedback of planning policy) was used to gain feedback on The Code from stakeholders, particular local authority members who found it hard to input due to time restrictions. The Code and supporting documentation was featured on partner websites and Groundwork Sheffield s website, along with having their own dedicated pages: Groundwork Sheffield ( aspx) Livingroofs.org ( and Green Roof Centre ( The Environment Agency together with the Homes and Communities NFRC - The Code - The Green Roof Guide - In additional to this The Constructor Group became the projects official media partner allowing information to be disseminated to a larger, relevant audience through articles and editorials. 6

7 The project team linked heavily with the National Federation of Roofing Contractors (NFRC), through the sponsorship of a Green Roof Award category at their annual Roofing Awards, held to an audience of 1,000 delegates. This has given The Code credibility and was instrumental in disseminating The Code amongst the target audience. The Awards provided the opportunity to promote, celebrate and reward green roofs which conformed to the best practice principles of The Code and The Green Roof Guide. Four awards in total were made in 2010 and 2011 based on level of craftsmanship, delivery performance and creativity of the green roof in line with The Code. A best practice study visit to Stuttgart (Germany) with stakeholders in year 1 of the project allowed stakeholders and the project team to see first-hand the impact that local government policy can have on increasing green roof coverage. The main problems encountered during the project were changes in team structure and co-financing arrangements. The consultation phase also took longer than expected so The Code document could not be finalised until early The Code was officially launched in May 2011 as part of the National Roofing Awards. The final dissemination event included a project summary seminar held in November 2011 to launch and celebrate the Green Roof Guide and overall success of the GRACC project. A list of Attendees can be viewed in appendix X. Hard copies of The Code were issued to stakeholders. Benefits and specification of green roofs The Code reinforced the need for minimum standards in relation to green roof specification, design, construction and maintenance to ensure maximum benefits were gained in relation to climate change mitigation and adaptation. The most important aspect of green roof design noted in The Code is that the depth of green roof substrate used is not less than 80mm. This is essential to ensure the long term sustainability of the roof in terms of water retention and biodiversity value. Key factors covered in relation to the specification of plant layers include plant water storage capacity, plant architecture (e.g. leaf size, shape and coverage) and physiology (e.g. transpiration tendencies etc) will affect the roof s performance and its tolerance to drought, wind, light, shade and pollutants. Different green roof aspects and climate aspects will expose vegetation to different climates. If the principles of The Code are followed maximum benefits will be gained in terms of: Temperature reductions in urban environments and properties due to increased thermal mass and cooling affect of vegetation Reductions in flash flooding risks due to the greater capacity to hold rainfall. Roofs built for this purpose would use plants with a high water storage capacity such as sedums Improving air quality. Increased space for biodiversity, in line with the Natural Environment and Rural Communities Act, Biodiversity Duty and the Natural Habitat legislation Natura, Greater substrate depths provide opportunities for more varied planting and more microhabitats. A roof seeking to improve local biodiversity (e.g. habitat creation) may require a specific mix of indigenous species (often selected by an expert ecologist). Biodiverse roofs can be designed to mimic various protected habitats particularly those lost to redevelopment or and can be designed to meet to objectives of Habitat Action Plans (HAPS). Demonstration of habitats created at different substrate depths. Taken from CIRIA, Building Greener,

8 The Code also supports existing legislation such as: The Kyoto Protocol, all EU countries are legally bound to cut their greenhouse gas emissions to 8% of 1990 levels by 2012 EU Energy Policy (Jan, 2007) - The European Commission s aim to reduce greenhouse gas emissions by 20% by Directive on Energy Performance of buildings - promotion of improvements of the energy performance of buildings within the EU EU Water Framework Directive including flood policy and urban waste water directive which aims to reduce declining water quality European Floods Directive Clean Air Act for Europe, May CAFÉ In terms of economic benefits green roofs built to the principles of The Code lead to energy savings due to the reduction in artificial cooling required in summer months. Supporting document The Developer s Guide to Green Roofs, demonstrates that buildings with green roofs lead to reduced void periods and can demand higher rents. Green roofs also open up access to greener clientele as they outwardly demonstrating an organisations commitment to sustainability issues. Due to the green roofs water holding capacity the drainage infrastructure and water storage requirements of new developments can be reduced leading to cost savings. Green roofs also have many social benefits as they create amenity space which can be used for recreation, community gardens or wildlife habitats. This has been shown to improve health and wellbeing. It is hoped that the awareness raising and dissemination activities of the project will lead to greater green roof uptake and job creation in the green roof sector to meet demand. After-LIFE To ensure its longevity Groundwork Sheffield has committed to keeping The Code and supporting documents available freely in the public domain on Groundwork Sheffield s website and dedicated webpage s for the next 5 years. The NFRC have agreed to be custodians for The Code for the next 5 years, committing to update it annually in partnership with GRO. The NFRC have disclosed that The Code has been the most heavily downloaded resource they have ever had on their site - such is the demand for and uptake of the document. GRO and GRACC have also been approached by the British Standards Institute (BSI) which is keen to develop a formal British Standard for green roofs based on The Code, which will highlight the document even further. Groundwork Sheffield will continue to promote The Code at all the events they attend and have commissioned ECUS Ltd to research the new planning framework to ensure the current Supplementary Planning Document remains viable. We aim to continue disseminating The Code and guidance documents to a range of appropriate level bodies such as Local Government Association, Royal Town Planning Institute, Institute of Environmental Management and Assessment (IEMA), and the Institute of Ecology and Environmental Management (IEEM). Groundwork Sheffield has committed to producing case studies on the 2011 NFRC award winners which will be disclosed in These will be uploaded to the projects website. We have also committed to update the 5 case studies already established with key performance characteristic set out in section 3.1 of The Code, if these will be disclosed by installers. 8

9 3. Introduction It is generally accepted that climate change is happening - focusing attention on the need to plan and adapt urban environments for changing future climates. This has resulted in new forms of urban design, notably the integration of landscape with buildings to bring about a naturally cooler and more climatically responsive built environment. Green roofs are considered part of this innovative sustainable building form. Green roofs can help to reduce the effect of climate change and form part of the adaptation solution to storm-water overflow, high energy consumption, the spread of non porous groundcover and the Urban Heat Island Effect. The UK has fallen significantly behind other European countries and North America in its uptake of green roof technology, and as a result are not realising the benefits green roofs offer in mitigating climate change. Other countries such as Germany have recognised codes of best practice which inspire confidence in the technology and its installation. The hypothesis to be tested through the project was that without a code of best practice in the UK, green roofs would not provide optimum performance in relation to climate change and confidence in the technology would be jeopardised and the opportunity would be lost for green roofs to become a mainstream form of urban design in UK towns and cities. This was proved through the extensive involvement of key stakeholders in The Codes design and content and high adoption of The Code by industry. In response to the hypothesis GRACC (Green Roofs against Climate Change) sought to develop a green roof code of best practice (The Code) for improving the quality of green roof implementation. Rather than a single standard against which all green roofs are judged, the GRACC project considered that The Code would encompass a broader set of principles and guidelines. The methodological solution adopted comprised of 4 key stages: A. Stakeholder mapping and identification B. Awareness raising and consultation C. Final production and dissemination D. Project planning (throughout) Each phase contained a number of activities and tasks as described below and illustrated in the attached GANTT in Appendix A. There was a focus around stakeholder engagement through Livingroofs.org s and Groundwork Sheffield s networks, with a focus on Local Authorities and the integration of green roofs into planning policy. A series of task groups, stakeholder meetings and workshops were designed. In addition, the project also sought to harness European best practice through a study visit. Expected results centred on the development of The Code along with supplementary documents and case studies. Dissemination activities included awareness raising events, regular reporting to the EBF and best exchange visits/events to green roof heavy areas to allow the sharing of best practice. Dedicated web pages would ensure the availability of information in the public domain. A series of innovation awards made to individuals adopting the principles of The Codes would celebrate The Code and integrate in into industry. The environmental benefits of the project were seen to be around maximising the benefits green roofs have for addressing climate change, most notably: Reducing temperature increases with urban environments Reducing flash flooding risks and improving the quality of storm water run-off, in keeping with The EU Water Framework Directive including flood policy and urban waste water directive Improving air quality Increasing spaces for biodiversity, in line with the Natural Environment and Rural Communities Act, Biodiversity Duty and the Natural Habitat legislation Natura,

10 4. Administrative part 4.1 Description of the management system The project working method can be divided into three key stages. Each phase contained a number of activities and tasks as described below and illustrated in the attached GANTT in Appendix A. An outline of the methodology is below. A. Stakeholder mapping and identification (duration: 4 months Feb - May 2009) Identifying and mapping relevant stakeholders (stakeholder map Appendix B), Engaging with stakeholders via letter, or telephone. Different methods of engagement were chosen for each stakeholder. Identifying key stakeholder groups identified; Central government, The Green Roof Industry, Local Authorities and Built Environment Professionals B. Awareness raising and consultation (duration: 22 months Mar Dec 2010) Establishing a database of consultees by registering on the project webpages Consulting on sections of The Code in year 2 through engagement and consultation activities including 8 workshops, 5 focus groups and 36 awareness raising events. Use of online consultation software to engage those with time constraints. Best practice study visit to Stuttgart occurred working in partnership with members of the European Green Building Federation (EBF). C. Final production and dissemination (duration: 12 months Jan - Dec 2011) Finalising The Code and Green Roof Guide. Both were made available on partner websites and some hard copies were disseminated at events. Official launch of The Code in May 2011 as part of the National Roofing Awards. Project summary seminar held in November 2011 to launch and celebrate The Code and Green Roof Guide and overall success of the GRACC project. D. Project planning (duration: throughout) Led by the Project Manager, The project team met monthly and communicated project progress against targets. The Project Manager also had regular contact with the Monitoring Team in the UK and was visited once a year to monitor project performance and resolve any questions and concerns. 10

11 Project management structure The project management was originally set out as below. However, prior to the project starting, there was a change in the staffing, due to restructuring within Groundwork Sheffield. Organigrammes showing the management structure and tasks undertaken in different periods can be viewed in appendix Q and S. An example of some of the tasks completed by the project team can be viewed in appendix C. Partnership agreements were made with The University of Sheffield and Beta Technology. These have previously been supplied to the Commision at the audit meeting. The process for appointing these partners or expert advisors is reveiwed in section 4.2. Copies of partnership agreements were submitted to the Commision during the audit in November An Expert Advisor was also recruited from Sheffield Honey Company to provide advice in relation to biodiversity and green roofs in terms of location, microhabitats and flora for bees and other wildlife supported by green roofs. This involved green roof site visits and review of the guidance for technical accuracy. The Community Champions project run in parallel to the project provided events and seminars to disseminate information about the The Code to community champions tasked with providing information on sustainable technologies to their networks in Sheffield. The University of Sheffield key tasks: To maintain stakeholder engagement throughout all stages of The Code production and create task groups Drafting technical sections of The Code and editing of full document for technical accurancy Undertaking dissemination activity with stakeholders including conferences, seminars and presentations Beta Technology key tasks: Desk based research into other documents on offer Stakeholder analysis to identify the task group membership 11

12 4.2 Evaluation of the management system A. The process The day-to-day management of the project was straightforward as there were no project beneficiaries to co-ordinate and all the project team were directly employed by the project co-ordinating beneficiary (Groundwork Sheffield).The process used to select Expert Advisors for the project was through a competitive tendering process and interview. Following an interview a final company was appointed based on pre-set selection criteria and tasks. A sub-contract agreement was then drawn up setting out the project task, outcomes and timescales. This also detailed the roles, responsibilities and rights of partners and common provisions. The project s second Expert Advisor was the University of Sheffield. The process for this appointment did not include an open tender due to the very specialist nature of the work involved. As a result, the University of Sheffield were appointed by direct treaty. Other Expert Advisors listed in the project financial sheets were selected to deliver or provide one-off, discreet services under the value of 5,000 so no open tendering process was deemed necessary. B. Project Management, problems encountered and added value of partnerships Groundwork Sheffield s Project Manager was supported by Groundwork Sheffield s Executive Director where needed. This arrangement worked well and there were no internal issues to report as regards overall management. A smooth handover occurred to the Development Officer on the departure of the Project Manager in late July Any problems/changes occurring to the project did not affect project outcomes and were dealt with immediately. These included; Clear Environmental Consultancy Ltd withdrew from co financing responsibilities due to new corporate priorities. Successful replacement funding was found in the form of the Homes & Communities Agency (HCA) with the shortfall being met by Groundwork Sheffield. The consultation phase took longer than expected. As a result we were not able to finalise and launch The Code until early 2011 at the National Roofing Awards The format of The Code has caused much discussion due to the differing priorities of the stakeholders. As a result, the Project team decided to create two documents The Code and The Green Roof Guide to meet these. Local Authorities representatives were finding it hard to attend consultation activities due to severe time constraints. To overcome this an online consultation portal was used to gain their views via a specially commissioned software application. The Added value of partnerships The project helped to strengthen existing partnerships as well as to build new ones. In particular, the link to Livingroofs.org provided us with access to the European Green Building Federation, whose members were able to help the Project Manager arrange and then host the best practice study tour. Another extremely valuable relationship was that with The Green Roof Centre. Whilst Groundwork Sheffield already had close ties to the Centre before receiving LIFE+ funding, the GRACC project helped cement these ties by involving Jeff Sorrill within the project through his role as Expert Advisor. Jeff was able to bring his technical knowledge of green roof performance and links to the University body of green roof research to feed into The Code and Guide. Another extremely beneficial and worthwhile partnership which emerged through our work was that with the National Federation of Roofing Contractors (NFRC) who helped the GRACC project to establish the GRO (Green Roof Organisations) task group. GRO is formed as an independent body representing the green roof industry Trade Associations and the key players in the green roof market. GRO committed to fully support the production of The Code, and provided members for one of the three specialist technical groups advising on The Code. A description of these can be found in appendix Y. 12

13 C. Technical and commercial application (reproducibility, economic feasibility and limiting factors), The Code and Guide will remain freely available in the public domain on key partner websites such as The Green Roof Centre and NFRC. The NFRC have committed to updating The Code for the next 5 years. The main issue surrounding the economic feasibility of what The Code suggests in relation to the minimum substrate depth advised in order to meet the environmental benefits as set out in the LIFE + objectives. A greater substrate depth increases the loading on the roof structure which may lead to increased costs in terms of extra structural supports in the roof span or type of roof decking required. This may not make it financially viable for some. Despite this and different commercial depth systems being on the market GRO was in full support due to the additional benefits gained. D. Comparison against the project objectives A table showing achievements against project objectives can be viewed in appendix R. E. Effectiveness of dissemination activities Information was disseminated successfully on partner websites; The Green Roof Centre, NFRC Livingroofs. org and The Green Roof Centre. A successful media partnership was established with the Construction Industry magazine which proved extremely successful as it was best placed to reach the various levels of suppliers, installers, specifiers and developers we were targeting. The benefit of the partnerships with GRO and NFRC in terms of disseminating information was the considerable reach it had to access significant and relevant individuals of not only the construction industry, but also policy makers, and potential and existing customers. In both 2009 and 2010 presentations were given at EcoBuild the worlds largest sustainable construction show held in London. The show has huge footfall of in excess of 40,000 visitors each year, more than 50 attended each presentation about The Code. Workshops and seminars were also provided across the country for local authority officers, green roof industry participants and building developers. Sessions were also held for members of the general public in open meetings. Constraints with dissemination activities included the problem of maintaining up to date material on webpages when negotiations are underway and the leaking of the current state of play would not necessarily be beneficial. Only a couple of e-bulletins were produced, primarily for the same reasons. Coupled with this only a relatively niche group of parties were interested in the finer details of the development of The Code because of this it was decided to cease green roof news and instead update news on the NFRC and Groundwork website where appropriate. F. The future: continuation of the project + remaining threats The NFRC have committed to being the custodians of The Code for the next 5 years as they hold the master copy of the document. They will review the document annually in partnership with GRO. Groundwork Sheffield have also committed to maintaining The Code and supporting documents on their website and dedicated web pages for the next 5 years. This will ensure The Code and supporting documents continued availability in the public domain. Members of NFRC website. Members of GRO and GRACC have also been approached by the British Standards Institute (BSI) which is keen to develop a formal British Standard for green roofs based on The Code. The main threat to achieving the overall aim of GRACC is that awareness of The Code will lessen over time. As a result the After Life Plan pays particular attention on how the partners involved can continue to maintain a high profile for The Code. The other threat is that partners do not keep up with commitments to publicise The Code, despite monitoring from GRO. Due to the new revised planning framework, Groundwork Sheffield has commissioned ECUS Ltd, an environmental consultancy to research this new framework to ensure the existing Supplementary Planning Document is viable and integrated into the planning framework. Any revisions made will be updated onto partner websites. 13

14 5. Technical part 5.1. Task by task - description Action 1: Dealt with in the administrative part (chapter 4) Action 5: Dissemination - Dealt with in chapter 4.2 Action 8: Financial Audit - Dealt with in the financial section please see the financial section (chapter 6) Action 2: Production of The Code and associated activity Description of activities: This action involved setting down key principles and guidelines for The Code to support the implementation of green roofs across the UK. Before anything could begin, a full review of existing standards, codes and norms was undertaken. This was conducted with input from Beta Technology and the Green Roof Development Officer as a desk-based piece of research. The second piece of research was to identify and establish the project stakeholders. Once the stakeholders had been identified, then the Green Roof Development Officer and Network and Dissemination staff started making contact with individuals to arrange meetings. Alongside this, the Project Manager worked closely with the Expert Advisor from The University of Sheffield to establish the general format that The Code should follow. The first draft of The Code was planned to be complete by December 2009, following a series of workshops, and focus groups. However the consultation phase took considerably longer than expected and was not completed until December It was agreed by the Project Manager that this additional time would be well spent during the consultation phase in order to gain buy-in and consensus from stakeholders. It was considered that this would result in The Code being more favourably received in the long-run. Overall, there was a strong sense of cooperation between the companies and organisations involved in the consultation and a willingness to debate openly in order to come to a common set of principles. It was decided that a task group, as envisaged in the original proposal, was not the most appropriate group to direct the project due to the large number of partners and disparate needs of each group. Instead three specialist technical groups were established with the stakeholders. These were: A technical roofing group (GRO) A vegetation advisor group (Dr Dunnett and Alun Rhys-Tarr) A regulatory group (EA & Natural England) The Project Manager and the green roof Expert Advisor met regularly with the above groups to draft relevant sections of The Code and Guidance. The different sections were then collated and a first draft was produced. The first draft was consulted on towards the end of 2010 with comments fed back before the final drafting in early The project team consulted with a wider audience via the use of an on-line portal to ensure those with limited time could still comment. The final Code was disseminated at an Event in late 2011 to key stakeholders. The Project Manager and Green Roof Development Officer also worked closely with s Head of Environmental Planning to develop a Supplementary Planning Document advice note for potential roll-out to other Local Authorities. This advice note has been well received by Local Authorities and is available online via the Green Roof Guide website - Consultation with local authorities regarding this document highlighted the need to map out the current green roofs in Sheffield to demonstrate current take-up. Groundwork Sheffield commissioned a study to complete this which can be viewed in appendix G. This is due to be revised due to changes to the Planning system. Environmental Consultancy ECUS has been appointed to research this. This new guidance will not therefore be available before the end of the project but we have committed to making this available. From 4th to 7th May 2010, five delegates (two from Groundwork Sheffield, one from Sheffield s Local Planning Authority Department, one from Livingfroofs.org and one from the Environment Agency) undertook 14

15 a best practice study visit to Stuttgart (Germany) and Linz (Austria), to see first-hand the impact that local government policy can have on increasing green roof uptake. It provided an opportunity to speak with people at the cutting edge of green roof legislation; to understand more about best practice techniques and the challenges for installing the technology. In Stuttgart, green roofs are requested on approximately 80% of any new dwellings and must have a substrate depth of 120mm in order to achieve the runoff coefficient of 0.3. This finding provided the project team with a strong evidence base for increasing The Code minimum substrate depth requirement to 80mm. (See Appendix G for a full write up of this visit). Best practice visit, Stuttgart The task group for GRACC changed from the original proposal to include a smaller group with representatives from Groundwork Sheffield and The Green Roof Centre (University of Sheffield). This worked well, and provided steer and direction to the Project Manager. The Code was not accredited by BREEAM; instead it was endorsed by the Environment Agency and the Homes & Communities Agency which were deemed most suitable for the type of documentation being produced. Performance against proposal: Original proposal Actual performance Expected results: To establish a UK code of practice with associated, standards, guidance and policy measures. A UK code of best practice with supporting documents was produced and dissaminated. Indicators of progress: Increased reference to green roofs in national policy and legislation Increased level of awareness of green roofs amongst Government Offices and other public bodies. 40 stakeholders consulted on production of Code 7 workshops held over the duration of the project Reference is now made in Environment Agency policy and Planning Policy Uptake of Code by Government Body sponsors of The Code (Environment Agency and Homes and Communities Agency) Achieved for year 1-37 Achieved for year Achieved for year 3-11 Total Achieved for year 1-2 Achieved for year 2-5 Achieved for year 3-1 Total

16 5 focus groups (including 3 with industry) 1 task group created (6 task group meetings over the duration of the project) 2 joint seminars with Swedish Partners Achieved in year 1-1 Achieved in year 2-3 Achieved in year 3-1 Total - 5 Task group created Achieved in year 1-1 Achieved in year 2-1 Achieved in year 3-2 Total joint seminar to Stuttgart 4th to 7th May in 2010 held. (See Appendix H for a full write up of this visit). Final dissemination seminar held later A further dissemination seminar was held in place of the second visit. Key performance indices: Code drafted Accredited by BREEAM 75% attendance at workshop meetings Each workshop to last 3 hours A minimum of 15 attendees at each workshop 80% of attendees at workshops report high level of satisfaction with consultation process (information collected via feedback forms). Workshops to be held in the following locations: London (x2), Sheffield, Liverpool, Bristol, Birmingham, Newcastle. Task group to include key stakeholders Yes No, but endorsed by the Environment Agency and the Homes & Communities Agency Achieved - evidenced through meeting minutes/ sign in sheets Achieved - evidenced through meeting minutes/ sign in sheets Achieved - evidenced through meeting minutes/ sign in sheets Achieved - evidenced through meeting minutes/ sign in sheets Achieved - evidenced through meeting minutes/ sign in sheets Achieved - evidenced through meeting minutes/ sign in sheets 16

17 The main problems encountered in the production of The Code and associated activities included: The consultation phase took longer than expected due to the different expectations and priorities of stakeholders. As a result we were not able to finalise and launch The Code until early 2011 at the National Roofing Awards. The format of The Code has caused much discussion due to the differing priorities of the stakeholders. As a result, the Project team decided to create two documents The Code and The Green Roof Guide to meet these everyone s expectations. There were issues related to the economic feasibility of The Code due to minimum standards decided by key stakeholders and the technical task group. A minimum substrate depth of 80mm was set in order to meet the environmental benefits as set out in the LIFE+ objectives. This caused a greater substrate depth increasing the loading on the roof structure which may lead to increased costs in terms of extra structural supports in the roof span or type of roof decking required. This may not be financially viable for some. Action 3: Deleted - Piloting of The Code is now incorporated into Action 2 - Production of The Code Action 4: Awareness Raising Description of activities The awareness raising and consultation phase ran over a period of 22 months from March 2009 until December During this period, the team: Held 7 workshops (consultation with wider audience - minimum of 3 hours) Held 5 focus groups (focused meetings with a sole type of stakeholder e.g. utilities or developers) Held 36 awareness raising events (shorter 1 hour events) Engaged 2,537 participants Engaged 183 local authorities (see appendix O) The project undertook the production of four guidance notes, five case studies and a supplementary Planning Document. These included; Habitat Action Plan (Appendix D) Developers Guide to Green Roofs (Appendix T) Supplementary Planning Document (Appendix E) Green Roof Guide (Appendix I) DIY Guide to green roofs (Appendix J) Seven case studies on five different green roofs which illustrate best practice from The Code and Guidance (Appendix K). Two of these are on 2011 NFRC award winners. The awareness raising sessions were attended mainly by the built environment professions, policy makers, planners and decision makers from Local Authorities. Where these events could not be attended due to time constraints an online portal was used to collect feedback. The events were promoted through Groundwork Sheffield and The Green Roof Centre websites and Key stakeholder networks. In addition, the Network and Dissemination role involved submitting editorials to sector specific press (e.g. Roofing and Cladding Magazine - see Appendix P), and circulating press releases. The majority of the awareness sessions were delivered on-site at Local Authority buildings across the country. No paid sessions were delivered as part of GRACC. The project team also attended several large scale events including Ecobuild (London) and the Greenbuild Expo (Manchester) where they delivered workshops for up to 50 delegates. (A full list of the awareness raising events delivered can be found in Appendix H. A partnership with NFRC saw the project sponsoring a green roof award in their annual awards ceremony. The first award was made in 2010 in front of an audience of over 1,000 delegates from roofing companies and organisations. Due to the timescales of the NFRC ceremony, no awards were made in 2009, and the overall number of awards was reduced from 25 to four (a runner-up and winner for both 2010 and 2011). However the awards made will have a higher impact due to the established profile of NFRC and high prominence of the award event, which have been held in central London and Brighton. LIFE+ and The Code has gained significant publicity from these awards. The entries were checked for checked for eligibility against the (emerging) Code principles by the Project Manager and Expert Advisor. 17

18 The main problem encountered with this section of work was the engagement of Local authorities with awareness raising activities in due to budget cuts leading to severe time constraints. Despite this engagement outputs were achieved. Performance against proposal: Original proposal Actual performance Expected results: To hold 36 awareness raising events Achieved in year 1-7 Achieved in year 2-15 Achieved in year 3-14 Total - 36 Indicators of progress: Increased knowledge of green roofs within the built environment professions Increasing confidence in green roof technology Increased reference to green roofs in local planning policy and links to other policy areas Key decision-makers attending 450 participants attending the events 150 Local Authorities engaged with the consultation process. Achieved Achieved Achieved Achieved Achieved in year Achieved in year 2-2,120 Achieved in year Total - 2,537 Total for year 1-29 Total for year 2-72 Total for year 3-83 Total Key performance indices: 75% attendance at each awareness raising event Each event to last 1 hour minimum Four events held in each of the 9 English regions 80% of attendees at awareness raising event report high level of satisfaction with consultation process (information collected via feedback forms) Achieved Achieved Achieved Achieved 18

19 Green roof, Stuttgart, Germany 19

20 Problems encountered Action 6: Guidance notes and case studies Description of activities: An important outcome from The GRACC project was the production of the Green Roof Guide and case studies to complement The Code. The target audience for these publications was intended to be broad, covering several sectors, including policy makers, construction developers, installers and sustainable technology practitioners. The Green Roof Development Officer worked closely with the Expert Advisor and relevant technical groups to produce suitable content for these publications. The layout and design was delivered through a mixture of in-house staff and specialist design companies. The project undertook to produce three guidance notes and five case studies, although a total of 4 guidance notes were produced by the end of the project. After three years the project has produced the following: Green Roof Habitat Action Plan Guidance (Appendix D) - this provides the reader with the latest research and information about designing roofs rich in flora and fauna. It stresses the environmental benefits of sustainable green roofs and clarifies the relationship between biodiversity and BREEAM points when in rooftop situations. It is aimed at those commissioning and installing green roofs. This supports Local Planning Authorities to put in place policy which will support biodiverse green roofs. It is aimed at planning policy staff. Supplementary Planning Document (Appendix E) - similar to above, but this document aids Local Planning Authorities develop a policy framework which supports all forms of green roofs - in particular it refers those adopting the policy to refer to The Code for quality assurance issues. It is aimed at planning policy staff. Green Roof Guide (Appendix I) - this is a condensed version of the online interactive Green Roof Guide available in pocket format. Suitable for a broad range of audiences. DIY guide to green roofs (Appendix J) - this give individual householders the information they need to construct small-scale green roofs on out-buildings and small structures. Whilst individual householders are not a key audience for the GRACC project, the team considered that enthusiastic individuals could help raise the profile of green roofs amongst the general public and increase consumer demand for green roofs on new homes and offices. Developers Guide to Green Roofs (Appendix T) - This document demonstrates the economic advantages of integrating Green Roofs into a development in the UK, if the principles of The Code are followed Five case studies (Appendix K) - on five different green roofs which illustrate best practice from The Code and The Guide. Performance against proposal: Original proposal Actual performance Expected results: High quality publications produced raising awareness of The Code and LIFE+ funding. The Code and Guide have been produced both electronically and in hard copy format. And are available freely in the public domain Indicators of progress: 3 guidance notes produced The target was exceeded as 4 guidance notes were produced in total: Green Roof Habitat Action Plan Guidance (Appendix D) Supplementary Planning Document (Appendix E) Green Roof Guide (Appendix I) DIY guide to green roofs (Appendix J) Developers Guide to Green Roofs (Appendix T) 20

21 Library of 5 case studies on different aspects of green roofs designed by working to The Code 9 produced - 5 of these show the different types of green roofs developed using the principles of The Code and 2 illustrate the 2010 NFRC award winner and runner up. The 2011 winner and runner up case studies will follow. See appendix K Major public bodies support The Code and are willing to jointly promote it Guidance notes and case studies available on project webpages Yes - Environment Agency, Natural England major green roof manufacturers and installers (via GRO), Homes and Communities Agency all support and promote The Code Available on the Green Roof Centre website www. greenroofcentre.co.uk Evidence from website hits that people are downloading and accessing information from the guidance notes Developers and manufacturers proactively submit information to GRACC for inclusion in guidance notes and case studies 536 people downloaded The Code from the NFRC in October 2011 alone. From March 2011 to Nov 2011 it received 2,135 page views. Yes - via GRO and NFRC Key performance indices: 3 guidance notes available by end of 2011 Growing number of case studies (above 5) BREEAM accreditation acknowledged on the guidance notes (quality assurance). Green Roof Habitat Action Plan Guidance (Appendix D) Supplementary Planning Document (Appendix E) Green Roof Guide - (Appendix I) DIY Guidance to green roofs (Appendix J) Developers Guide to Green Roofs (Appendix T) These are now available on the project website 9 to be produced see Appendix K. The afterlife plan contains plans to develop case studies further to include key performance characteristics if these will be given by installers. Case studies on the 2011 winners will follow No longer applicable The main problem encountered under this action were the production of the Supplementary Planning Document. The document originally produced is now invalid due to changes in the current planning framework. To counteract this ECUS have been appointed to research the new planning framework and how green roofs can be best integrated into it. Action 7: Green Roof Innovation Awards Description of activities: The aim of the annual Innovation Awards was to acknowledge creative & sustainable green roof developments, which would ultimately inspire confidence in the technology. The Award was not envisaged to be financial, but a recognition of green roof excellence. The strategy of the number of awards distributed changed when a successful partnership developed with the National Federation of Roofing Contractors (NFRC). Initially, their Chief Executive came onboard with the GRACC project to assist with realising the 21

22 project objectives. However leading on from that, NFRC invited GRACC to support and advise on a green roof award category as part of NFRC annual national Roofing Awards. This was a huge opportunity to get The Code in front of the largest body of roofing contractors and the wider membership of associated building professionals. The project task group agreed to sponsor the NFRC Green Roof Award Category and the first award was made in 2010 in front of an audience of over 1,000 delegates from companies and organisations. Because of this and the timescales of the NFRC ceremony, the number of awards distributed was reduced from 25 to 4 (a runner-up and winner in both 2010 and 2011) in line with the number of award ceremonies we could support within the projects timeframe. Despite the reduction in the number of awards this had higher impact due to the established profile of NFRC and high prominence of the award event, which have been held in central London and Brighton. LIFE+ and The Code has gained significant publicity from these awards. Because of this the number of press releases also had to be reduced. Again it was not felt that this impacted on the overall awareness of The Code due to the high profile of NFRC. Each year, the National Roofing Awards are publicised widely and are open to any roofing contractor, developer and/or construction teams who have completed green roof projects in that year within the UK. The applicants were then screened and checked for eligibility against the (emerging) Code principles by the Project Manager and Expert Advisor. The next stage was to short list from the over twenty applicants down to five. The final five were then presented to a judging panel (composed of roofing practitioners and training specialists from the construction industry) to select the runner up and winner based on level of craftsmanship, delivery performance and creativity. The submissions for both 2010 and 2011 were of a high calibre and over twenty applicants submitted each year. The GRO Code document Showing the 2010 winner - Alumasc Rockliffe Park Hotel near Darlington in the North East. 22

23 Performance against proposal: Original proposal Actual performance Expected results: 25 Awards made over the course of the project s lifetime The number of awards has been reduced from 25 to 4 - a runner up and a finalist for 2010 and one for This was due to award timescales. The 2011 winner and runner up were: Alumasc Exterior Building Products (with Roofclad Systems) (Rockliffe Hall Hotel) Alumasc Exterior Building Products (with Tilbury Contracts) (Regent s Place, London) The 2012 winners will not be announced until after the project end date. 25 press releases (on each winner) drafted for circulation over the project s lifetime 25 new case studies produced The numbers of press releases were substantially reduced due to the reduction in the number of awards given. 4 press releases have been produced in regard to project launch and consultation along with the announcement of the 2011 award winners (see Appendixs L, M and U). Another will be produced on the 2012 award winners after the project has ended for the case studies in total will be produced through the project. 5 showing the different types of roofs constructed using the principles of The Code and 4 on the winners and runner up of the 2010 and 2011 NFRC green roof awards (See Appendix K). The reduction in numbers is due to the sponsorship of the NFRC awards Increased awareness of The Code and the GRACC project via promotion of the Awards Increased uptake of The Code 1,000 businesses attending the awards each event. Uptake of The Code document via the NFRC website The NFRC states that The Code is the most downloaded document from their website. 536 people downloaded The Code from the NFRC in October 2011 alone From March 2011 to Nov 2011 it received 2,135 page views The Awards will assist GRACC in gathering additional information on green roof case studies Award panel established meet once a year High profile individuals associated with the GRACC project 4 case studies on the winners and runners up of the 2010 and 2011 award winners. To view the Judging Panel for National Roofing Awards 2010 see Appendix O. This can be seen from the Judging panel see Appendix N. 23

24 Indicators of progress: The Awards receive good publicity Increase in applicants year on year The project team coordinated with NFRC communications team to publicise the awards (an example press release can be seen in appendix U) 22 applicants for the awards made in 2010 and 27 in 2011 Action 9: After-LIFE communication plan - See section After-LIFE communication plan 5.2 Evaluation The methodological solution adopted by the project comprised of 4 key stages: A. Stakeholder mapping and identification 1. Engage with the existing green roof industry and interested parties 2. Tap into the existing knowledge of best practice within the industry B. Awareness raising and consultation C. Final production and dissemination 1. Draw all knowledge on best practice into one document 2. Disseminate that documents through the very sector that would benefit from its use D. Project planning (throughout) It was recognised early in the process that the green roof industry in the UK would have to buy-in to the new Code from a very early stage. Therefore, it was vital that an influential body within the industry was capable and willing to act as a catalyst for engagement by the existing and emerging, active green roof industry suppliers. The project was extremely fortunate in that the National Federation of Roofing Contractors (NFRC), the largest body of roofing related trade association in the UK was strongly in favour of The Code and willing to support it. The support came in the form of first bringing together the group which became known as the Green Roof Organisation (GRO), then facilitating GRO into a forum to support the creation of The Code. The NFRC also appointed the Chair for GRO - John Tebbit, Industry Affairs Director for the Construction Products Association. The result of this collaboration was not only excellent input and guidance from the chair, but a near guaranteed adoption of The Code by the roofing and wider construction industry on its completion. Therefore, through this process stage A of the methodology was achieved, with buy-in guaranteed. This stage was very cost efficient with little financial outlay required to bring together, probably the most relevant, influential and affected parties in the UK. The members of GRO were keen to input content for The Code and assigned a Technical Advisory Group (TAG) to work with us on the development of The Code. This contributed to all stages of the methodology. The level of technical knowledge and industry competence added a great deal of value to the value of The Code. This was highly cost effective, with TAG members only requiring minimal day rate costs to participate in the process. The drawing in and combining of best practice into one document was well supported by the TAG. However, getting the TAG to agree on particular elements of best practice did raise some issues due to the different priorities of stakeholders. A great deal of time was spent on just a few crucial sentences, these mostly related to the minimum substrate depth. Some members within the TAG, although acting independently, were very aware that making recommendations in The Code that supported thin substrate depths could affect particular suppliers within the current green roof market. However, ultimately wording was agreed that all parties were happy with, and that we felt would raise the standard of green roofs enough to make a genuine difference to their performance in relation to climate change. As with stage A and B, TAG members readily engaged and best value was achieved for the project. Stage C has also been successful; the NFRC has reported that The GRO Code is the single most downloaded guidance they have on their website. Considering they have a huge range of guidance covering all of the roofing industry systems, this is a remarkable fact, and one which demonstrates the need for The Code and the timeliness of its production. Members of GRO have also been keen to distribute The Code to their customers, clients and contractors. In addition to direct dissemination through the existing industry, 24

25 the project worked hard to raise awareness to a far wider audience through presentations, seminars and press releases. These are listed elsewhere in this document. The annual NFRC Roofing Awards were also a tremendous vehicle for informing a vast roofing industry on not only The Code, but also the climate change benefits of green roofs. Again all of the above proved to be, a very cost effective process for the project. The one activity which was less successful and did not represent good value for money was the use of online software to undertake the public consultation of some elements of The Code and guidance. Despite considerable awareness raising amongst Local Authority officers, environmental professionals and the general public the response rate was very low and very disappointing for the project. An evaluation of the original tasks set out in the initial application can be seen in appendix S. 5.3 Analysis of long-term benefits 1. Environmental benefits a. Direct / quantitative environmental benefits ii) LIFE+ Environment Policy and Governance: The production and dissemination of The Code document and associated supporting documents reinforce the need for minimum standards in relation to green roof specification, design, construction and maintenance. These principles if followed lead to maximum benefits in relation to climate change mitigation and mitigation. Green roofs are an excellent tool to mitigate environmental challenges faced by local authorities. The most important recommended environmental design aspect within The Code is that the depth of green roof substrate used is not less than 80mm. This is essential to ensure the long term sustainability of the roof in terms of water retention and biodiversity value. The table below taken from the 2011 German FLL guidelines demonstrates the added retention value offered by an 80mm substrate depth in comparison to lightweight systems. Type of greening Course depth in cm Water retention - annual average in % Annual coefficient discharge Extensive greening ,60 > ,55 > ,50 > ,45 > ,40 Intensive greening ,40 > ,30 > 50 > 90 0,10 25

26 The other key principle covered is in relation to the correct selection of vegetation in relation to the design requirement of the roof. Factors covered include plant water storage capacity, plant architecture (e.g. leaf size, shape and coverage) and physiology (e.g. transpiration tendencies etc). This ensures the roof is fit for purpose and is tolerant to drought, wind, light, shade and pollutants. Other benefits gained from these key principles include; Temperature reductions in urban environments due to increased thermal mass (substrate depth) and cooling affect of vegetation Reductions in flash flooding risks due to the greater substrate depths capacity to hold rainfall. The quality of storm water run-off was also improved due to the substrates filtering capacities in line with EU Water Framework Directive. Planting with succulents plants such as sedums would also increase the water storage capacity of the roof Improving air quality. Increased space for biodiversity, in line with the Natural Environment and Rural Communities Act, Biodiversity Duty and the Natural Habitat legislation Natura, Greater substrate depths provide opportunities for more varied planting and more microhabitats. A roof seeking to improve local biodiversity (e.g. habitat creation) would require a specific mix of indigenous species (often selected by an expert ecologist) as advised in The Code. These benefits are described in more detail below. Energy Thermal impact Buildings are responsible for ~50% of the UK s CO2 emissions. A high proportion of these emissions are from heating and cooling. Reducing the energy consumption of the UK s buildings will reduce their contribution to climate change. Green roofs can significantly reduce the cooling load of a building, resulting in reduced air cooling requirements and therefore reduced energy consumption and associated output of atmospheric carbon. The UK spends more money artificially cooling commercial buildings in summer than it does heating them in winter. Green roofs have been shown to impact positively on a building s energy consumption by improving its thermal performance; this varies depending on the weather. The potential direct savings from a green roof as advised in the CIRIA Building Greener report are advised below. Potential direct savings from green roof implementation (Banting et al, 2005) Category of energy saving Energy savings Demand load reduction from direct energy production Energy saving per m 2 of green roof 4.15 kwh / m 2 / year kw / m 2 / year The Developers Guide to Green Roofs produced by The Green Roof Centre advises that on a summer day, the temperature of a gravel roof can increase by as much as 25 C (77 F), to C ( F). Covered with a Green Roof, the temperature of that roof will stay at 25 C (77 F), saving energy costs. Poorly insulated roofs, as found on many existing buildings, will lead to overheating of spaces beneath them during the summer and excessive heating demand during the winter. By retrofitting green Traditional Roof Green Roof roofs, both air conditioning and heating usage is decreased. An energy study undertaken by the City of Chicago estimated that, with whole scale greening of the cities rooftops, energy to the value of $100M could be saved each year due to the reduced demand for air conditioning. This would to a reduction in peak demand in the order of 720MW. 26

27 Urban Heat Island Effect Urban areas can be up to 7 C warmer than the surrounding countryside due to the large areas of asphalt and other dark materials they contain. During the hot summer of 2003, night-time temperatures in London reached 9 C higher than outlying rural areas. Green roofs have very different thermal qualities to conventional roofs. They tend to reflect more of the sun s rays and shade and insulate the underlying structure this reduced the temperature of the roof surface. The evaporation of water from the soil and transpiration of water from leaves cools the roof. A study in Toronto (Banting et al, 2005) modelled the effect of green roofs on the city s urban Heat island concluded that widespread greening of roofs would reduce local ambient temperature by between 0.5 C and 2 C. It was calculated that this could lead to city-wide indirect savings from reduced energy demand for cooling of $12 million, equivalent to 2.37 kwh/m_ per year. Indirect savings are due to reduced temperature differences through the roofs and walls of buildings. The reduction in energy requirements was estimated to reduce carbon dioxide emissions from power stations by tonnes per year. (CIRIA, Building Greener, 2007) Water attenuation An established green roof will significantly reduce peak flow rates and total rainwater runoff compared to a conventional roof. This dramatically reduces the drainage infrastructure and water storage requirements on site. Green roofs store rainwater in the plants and substrate and release water back into the atmosphere through evapotranspiration and evaporation. In summer, green roofs can retain 70-80% of rainfall and in winter they retain 10-35% depending on their build-up. Generally the deeper the substrate the greater the average annual water retention. This is demonstrated by the table on page 25 taken from the FLL guidelines. With over 75% of rainwater becoming runoff in urban areas green roofs help reduce the pressure on the already strained sewer system reducing the chance of localised flooding. The diagram demonstrates the delayed time taken for water to run off a green roof in relation to a normal roof. Taken from CIRIA, Building Greener report,

28 Pollution control The urban heat island effect exacerbates ground-level ozone production, which is formed by a reaction between volatile organic compounds and nitrous oxides catalysed by heat and sunlight. It is classified as a pollutant and is the principal component of smog. Rainfall runoff from roofs can also be polluted (e.g. from bird droppings or atmospheric pollution). Green roofs can improve local air quality through mitigation of the urban heat island effect and by removing airborne particles, heavy metals and volatile organic compounds from the local atmosphere. The roof can retain and bind contaminants that are introduced to the surface either as dust or suspended/dissolved in rainwater. Johnston and Newton (2004) stated that 95 per cent of heavy metals are removed from runoff by green roofs and nitrogen levels can be reduced. This in turn reduced air and water quality. Biodiversity Different types of green roofs, substrate and vegetation will support different habitats and species. Biodiverse roofs can be designed to mimic various habitats. They can be especially important as a tool to recreate the pioneer (wasteland) communities that are sometimes lost when redevelopment takes place. Within urban areas, it is very often neglected brownfield sites that are the most biodiverse. The best designs may often be ones that support a range of habitats for wildlife, including substrates, microhabitats and substrate depths. Green roof designs should vary in different parts of the UK to meet the objectives of local Biodiversity Action Plans. A local biodiverse green roof on Sharrow School in Sheffield has been declared a Local Nature Reserve due to the variety of plants and habitats it contains. Sharrow School b. Relevance for environmentally significant issues or policy areas This project supports the following pieces of environmental legislation and policy areas through the environmental benefits the technology offers; The Kyoto Protocol, EU countries are legally bound to cut their greenhouse gas emissions to 8 % of 1990 levels by 2012 The European Commission proposed a unilateral 20% reduction in greenhouse gas emissions by 2020 through the EU Energy Policy (Jan, 2007) The European Strategic Energy Technology Plan (2006) sets out the development of technologies relating to low-energy buildings, energy conservation and carbon capture Since January 2006, Member States have been required to meet the 2002 Directive on Energy Performance of buildings, this includes the promotion of improvements of the energy performance of buildings within the EU 28

29 EU Water Framework Directive including flood policy and urban waste water directive which aims to reduce declining water quality European Floods Directive Clean Air Act for Europe, May CAFÉ The Code meets the criteria of relevant complementary documentation including; British Standards - Building Design British Standards - Structural Design British Standards - Maintenance Health & Safety Workmanship British Standards - Metal Roofing Specifications British Standards - Bitumen Waterproofing Specifications British Standards Plastic & Rubber British Standards - Mastic Asphalt Waterproofing Specifications Waterproofing Specifications British Standards - Mastic Asphalt Waterproofing Specifications Liquid Waterproofing Specifications British Standards - Timber Specifications British Liquid Waterproofing Specifications Green Roof Guidance 2. Long-term sustainability a) Long-term / qualitative environmental benefits ii) LIFE Environmental Policy and Governance The long-term sustainability of this project may not be like many others funded through LIFE+. The primary focus of this project was to create a legacy document which would provide a benchmark for current green roof best practice. It was important that the document was adopted by the UK construction industry as the recognised guidance for the country. Therefore, from the outset of GRACC it was in the project team s mind that buy-in needed to be gained from a major construction organisation. The NFRC (National Federation of Roofing Contractors) stepped forward as being willing to undertake the role of umbrella industry body, as it already represented most of the green roof industry suppliers in the UK, and had its self been investigating how an independent national Green Roof Guide could be produced for a number of years. The NFRC was established in 1892 and now represents almost 70% of the UK roofing industry. Through the partnership working of the GRACC Team and the NFRC, a national green roof industry forum was formed under the name GRO (Green Roof Organisations). It was with the aid of GRO members that the GRO Green Roof Code was written. As the project progressed the NFRC remained instrumental in the development of The Code, and stated that they would be keen to be the custodians of The Code on its completion. They also stated that they would be willing to maintain the GRO Forum and to instigate and apply and annual review of The GRO Code and update it as required. Therefore in terms of long-term sustainability of The GRO Code, and as such the GRACC project, is assured into the foreseeable future. In fact the NFRC and GRO are in the process of enhancing the status and profile of The GRO Code by establishing a network of training providers who will deliver courses to green roof installers, contract managers and green roof maintenance workers, using The Code as the core text. b) Long term qualitative economic benefits The development and dissemination of The Code document will ensure best practice green roofs are installed which maximise the benefits of the roof in terms of climate change mitigation and adaptation. This can lead to many costs savings long term for buildings featuring a green roof. In relation to Local Authorities adoption of The Code and Supplementary Planning Document due to dissemination and awareness raising activities will integrate The Code into the planning framework and lead to greater uptake amongst built environment professionals they liaise with. Over 185 Local authority personnel were engaged through the project and it is hoped information will be passed on through their networks. 29

30 Abiding by the principles of The Code in relation to substrate depth will ensure buildings housing a green roof use less energy due to the reduction in artificial cooling required. The exact savings of these benefits can be reviewed in 4.3 section 1. The Developers Guide to Green roofs advised that properties featuring a green roof built to the principles of The Code are more sustainable and can demand: Higher rents - leading to greater profit margins for developers Have less letting void periods Increased property value Reduces surface water runoff requirements and size and complexity of the on site drainage system Improves staff attenuation rates and productivity Lower tenant and employee turnover Green roofs can increase a building s marketability as they are an easily identifiable symbol of the green building movement and Corporate Social Responsibility. This has been shown to open up new contract opportunities with greener clientele. Moorgate Crofts - Moorgate Crofts is fully occupied with tenants unlike a similar local building without a green roof in close proximity. Green roofs complement SUD strategies and rainwater attenuation control on developments. An established green roof will significantly reduce peak flow rates and total rainwater runoff compared to a conventional roof. This dramatically reduces the drainage infrastructure and water storage requirements on site. Green roofs have also been found to extend the life of the waterproof layer on a roof as it protects it from ultra-violet light and temperature change. Green roofs have now been shown to double, if not triple the life of waterproofing membranes. In terms of gaining planning consent/permission incorporating a green roof into a development may gain support which can help to secure planning consent. It may be possible to retrofit green roofs on certain buildings without planning consent, although the planning authority should be consulted if there is doubt. Green roofs work well with other forms of sustainable technology including Solar Thermal and Photovoltaic (PV) Panels and rainwater harvesting systems for non potable applications. It has been shown that the cooling effect of a green roof leads to performance improvements from a PV system mounted on A-frames, as the roof is cooler and the PV cells work at a higher efficiency. This again may lead to cost savings. 30

31 c) Long term qualitative social benefits Green roofs can positively affect the urban environment by increasing amenity and green space in urban areas Green roofs can serve a number of functions and uses, including: Community gardens (e.g. local food production or co-ops), Commercial space (e.g. display areas and restaurant terraces or business units) Recreational space (e.g. lawn bowling and children s playgrounds). Wildlife habitats Education on schools Benefits of the Sharrow School s green roof terrace Research has proven that access to green space has social benefits in relation to job creation and health. In relation to job creation the support offered by The Code in relation to installation and design may lead to an increased number of installations. The Code also offers advice which shows potential for green roofs previously thought unsuitable. This surge in the market will create new job opportunities related to manufacturing, plant growth, design, installation, and maintenance. In relation to health the reduced pollution and increased water quality that green roofs bring can decrease demands on the health care system. Green roofs can serve as community hubs, increasing social cohesion, sense of community, and public safety. This increases exercise. Use of a green roof for food growing and exercise will lead to increased fitness and a healthier diet. 3. Replicability, demonstration, transferability, cooperation The potential for replicability of The Code is very high, not only for other EU countries, but also across Asia and Pacific Rim. The methodology for this project was quite simple, and assuming that other interested countries have some kind of national association for the roofing industry, a similar approach could be used to achieve a similar outcome to the UK s. The knowledge gained throughout this project regarding the drivers that move things forward, and barriers that needed to be overcome, would be transferable to conditions in many other countries. The Code will be available free to increase its use so it has limited benefits for commerciality. This was a very costs effective measure of ensuring best practice green roofs are implemented. 31

32 4. Innovation and demonstration value This project was unique in that it was environmentally-led. Groundwork Sheffield and the Green Roof Centre are independent from the green roof industry and as such did not suffer from commercial pressures and industry influences. Through the innovative partnership consortium of local authority, social enterprise, private sector, Government Department and Further Education organisations, The Code development was ensured a clear steer. The Innovation Awards in partnership with the National Federation of Roofing Contractors (NFRC) was a huge success. The Awards took the message of The Code right to the grass roots roofing industry, raising awareness and interest in the recommendations of The Code. 5. Long term indicators of the project success The quantifiable indicators of the longevity of this project can be seen in the adoption of The Code by the NFRC. The NFRC drive the quality and best practice of all roofing in the UK, they were quick and keen to take on the future management of The Code as part of their portfolio of roofing guidance and standards. In addition to the long term indicators of The Code such as revision and updates through the NFRC, there is also a clear intention from the green roof industry to embrace and endorse The Code. This is not least because the recommendations within The Code increase some of the materials required, but also increase the probability of the long term health of the green roof. In this way green roofs installed to the recommendation not only require more materials, therefore potentially increasing profits, but also they are likely to perform better, thereby reducing warranty issues and costs. Wide spread adoption of The Code will lead to more, better quality green roofs across the UK. More, better quality green roofs will in turn provide both soft outcomes such as increased biodiversity potential and habitat creation, and hard outcomes such as less need for excavation and below ground water storage. 32

33 5.4 Dissemination issues The original proposal set out the following dissemination plan: A number of publicity tools will be utilised to achieve this including a regular e-bulletin, dedicated web pages and press releases/articles for journals. Any organisation or individual with an interest in green roofs will be encouraged to become members of the information ing list. The project will provide regular updates via e-bulletins and have password protected sections of the website to access the latest news and progress. Other methods of dissemination of knowledge to be used: Via Groundwork Sheffield and Livingroofs.org websites and existing networks Awareness raising events Events Focus groups Website Publications Media Press releases The project has been especially well received by the press and media, with over 11 feature length editorials in various publications. An example can be viewed in appendix P. These include: BALI Landscape News, Spring 2009 Green roofs are coming be prepared BALI Who s Who feature, June 2009 The Green roof code Green Places, March 2009 How should your green roofs grow? Roofing Magazine, April 2009 Fancy growing a roof? Roofing Cladding and Insulation Magazine, March 2009 Offering Green Roof Guide Planteria Magazine, December 2008 The green roof code Constructor and Architect Magazine, March 2009 The green roof code of best practice Green Places, May 2009 Giving green roofs the green light Roofing Today, July 2009 The green roof code Irish Construction Magazine, Jan 2009 The Green Directory 2009 Green roofs are coming Green Build News, October 2009 The Green roof code Dissemination: overview per activity The deliverables of the project include; Present 36 awareness raising events on The Code Consultation 40 Stakeholders Hold 7 workshops Engage 450 participants at events Engage 150 Local Authorities in the consultation process Hold 5 focus groups Hold 6 task groups Establish dedicated web pages Production of 5 case studies by Groundwork Sheffield on different aspects of green roofs designed working with The Code Produce 25 case studies on awards winners Production of 25 press releases on award winners Make 25 life awards LIFE + awards Produce 3 guidance notes including a supplementary Planning Document produced by Groundwork Sheffield Produce quarterly e bulletin on developments Facilitate 2 joint seminars on The Code 33

34 Method Events Consultation Targets To present 36 awareness-raising events on The Code Hold 7 workshops Consult 40 stakeholders 150 local authorities engaged in the consultation process Engage 450 participants at events Delivered 36 awareness events 7 workshops held Consulted 165 stakeholders Engaged 183 local authorities and 566 Local authority personnel Engaged 2,537 participants Focus groups Hold 5 focus groups Hold 6 task groups 5 focus groups held Held 4 task groups Web page created Partner sites promoting The Code Website Publications and guidance notes To establish dedicated website To produce 3 guidance notes including a supplementary planning document Website created and partner sites promoting The Code. The Code is available on key partner websites including; Groundwork Sheffield ( sheffield/what-we-do/major-initiatives/gracc.aspx) Livingroofs.org ( org-living-roofs/gro-background.html) Green Roof Centre ( green_roof_code/life_) Editorials in publications (appendix P) Guidance notes Habitat Action Plan (Appendix D) Supplementary Planning Document (Appendix E) Green Roof Guide (Appendix I) DIY Guide to green roofs (Appendix J) Developers Guide to green roofs (appendix T) Five case studies on five different green roofs which illustrate best practice from The Code and Guidance (Appendix K) 34

35 Problems encountered No problems were encountered with awareness raising and workshop events Objective reached? & Feedback Yes Feedback received from all events was positive We had some initial difficulty attracting sufficient Local Authority representatives to the consultation workshops and events. When investigated further, it was found that Local Authority staff (especially those in planning) were experiencing severe time constraints due to budget cuts and staff reductions. This was making it increasingly difficult for such staff to attend meetings outside of core working requirements. In order to overcome this problem, The Code consultation was also conducted on-line via a specially commissioned software application. The software enabled us to efficiently and effectively collate and view feedback and comments from consultees. Yes - exceeded Feedback Natural England into The Code proved invaluable. Events were held at large scale renowned shows such as Ecobuild which attract around 40,000 visitors a year. This enabled us to exceed the number of participants we engaged. It was decided that a task group, as envisaged in the original proposal, was not the most appropriate group to direct the project due to the large number of partners and disparate needs of each group. Instead three specialist technical groups were established with the stakeholders. These were: A technical roofing group (GRO) A vegetation advisor group (Dr Dunnett and Alun Reece-Tarr) A regulatory group (EA & Natural England) Partially Some sections of The Code were heavily debated over in focus and task groups due to the different agendas of the members of the task group. This took more time than expected delaying the first draft of The Code. The team found it hard to maintain a level of up to date material for webpages was difficult when progress on The Code was delayed due to negotiations and the leaking of the current state of play would not necessarily be beneficial. Yes The NFRC reported that The Code was the most downloaded document from their website. 536 people downloaded The Code from the NFRC in October 2011 alone From March 2011 to Nov 2011 it received 2,135 page views. The main problems encountered were: Producing the Supplementary Planning Document (SPD) was hard as Local Authorities had their own format and mechanism for developing SPD s. The planning framework also changed part way through the project meaning the new planning system had to be researched further in order to start producing another document. Yes - exceeded Over 11 feature editorials placed in key sector magazines The format of The Code has caused much discussion due to differing needs of stakeholders. 35

36 Press releases To produce and disseminate quarterly e-bulletins on developments and progress within green roof technology. Quarterly e-bulletin Press release every second month 1 e-bulletin Joint seminars To facilitate two events with ISU (Sweden) for information sharing and exchange of best practice in 2009 & best practice visit to Stuttgart in May 2010 Green roof awards To make 25 Innovation Awards over the project lifetime 25 press releases produced on the winners 4 awards made in 2010 and 2011 through green roof category in National Federation of Roofing Contractor awards (NFRC) 1 press release produced on the 2010 winners. One to be produced on the 2011 winner after the projects end. Case studies 25 case studies produced on the winners Library of 5 case studies on different aspects of green roofs designed by working to The Code 9 cases studies produced see Appendix K 2 to follow after winners of 2012 awards are released 36

37 An e-bulletin and press release was not sent out quarterly as maintaining a level of up to date material for press releases/ e-bulletins is difficult when progress is either slow or negotiations are underway, and the leaking of the current state of play would not necessarily be beneficial. Because of this it was decided to cease green roof news and instead add updated onto the NFRC and Groundwork website where appropriate. No Take-up by the press was considerable with other 11 feature articles in relevant sector publications The number of press releases related to the NFRC awards was also reduced due to the reduction awards to be given from 25 to 4. One best practice visit was intended to take place with Swedish counterparts based at ISU & and the Scandinavian Green Roof Centre in Malmo. However despite numerous attempts to contact them, the Malmo team were not forthcoming. So an alternative strategy was devised working in partnership with members of the European Green Building Federation (EBF) to visit Stuttgart from the 4th to 7th May in No Feedback from the visits was positive (see appendix G) To compensate for the Malmo visit a seminar was held to 20 delegates to disseminate the final document Code document and celebrate its release. Overall number of awards given was reduced from 25 to four (a runner-up and winner for both 2010 and 2011) due to the number of awards ceremonies being held within the project timeframe. Despite this the exposure offered through the awards had higher impact due to the established profile of NFRC and high prominence of the award event, which have been held in central London and Brighton. This in turn reduced the number of press releases and case studies produced on the winners. 9 case studies will be produced through the project in total. 4 on the winners and runners up of the 2010 and 2011 NFRC awards and 5 demonstrating the different roofs built to the principles of The Code. Yes Feedback from the NFRC regarding the green roof category was positive Yes 37

38 4.4.2 Layman s report The project In 2009 Groundwork Sheffield secured 457,206 of European LIFE+ funding to deliver the project Green Roofs Against Climate Change project (GRACC). The project s main aim was to create a green roof code of best practice; setting standards for the design, installation and maintenance of green roofs across the UK. LIFE+ is the EU s funding stream for supporting environmental policy development across Member States. It is generally accepted that climate change is happening. The widespread flooding across England in July 2007 served to heighten public awareness of the potential effects of adverse climatic conditions - focusing attention on the need to plan and adapt urban environments for changing future climates. This has resulted in new forms of urban design, notably the integration of landscape with buildings to bring about a naturally cooler and more climatically responsive built environment. Green roofs are considered part of this innovative sustainable building form. Impermeable rooftops account for over 35% of space in urban areas illustrating the scope there is to implement green roof technology. Green roofs can help to reduce the effect of climate change and form part of the adaptation solution to storm-water overflow, high energy consumption, the spread of non porous groundcover and the Urban Heat Island Effect, whilst also creating affective wildlife habitat. However, green roofs can only provide these environmental benefits if designed and installed in a way that ensures that minimum performance criteria are met. A glossary of terms can be found in appendix X. The project objectives were to address climate change by increasing the quality of green roofs in the UK, by working with key stakeholders to produce a document or Code to support anyone who is considering, designing, specifying, installing or maintaining a green roof, or those involved in the strategic planning of green infrastructure. There are no current guidelines relating to this in the UK but there are in other countries such as Germany, which has increased confidence in the technology. Therefore the underlying hypothesis for the project was that without The Code, confidence in the technology would be jeopardised and the opportunity would be lost for green roofs to become a mainstream form of urban design in UK towns and cities. Consultation with stakeholders highlighted the need for two documents rather than a single standard against which all green roofs are judged. The project considered that The Code would encompass a broader set of principles and guidelines: a technical Code document and an interactive web based Green Roof Guide, containing more detail on specific parts of The Code. All parties using this Guide who require technical information should have a copy of the GRO Code: www. greenroofcode.co.uk and the most recent version of the FLL Guidelines. Complementary documents such as a set of green roof guidance notes, green roof habitat plan, developers guide to green roofs and a supplementary planning document were produced to help integrate green roofs into the planning framework and address barriers to the uptake of green roofs. The Code was developed in partnership with national and European experts, including The Green Roof Centre at the University of Sheffield, National Federation of Roofing Contractors, Livingroofs.org, GRO (Green Roof Organisation), the Environment Agency and the Homes and Communities Agency. The Code was published and edited by Groundwork Sheffield ( (ISBN: ). The Code meets the criteria of relevant complementary documentation including the following building Regulations (building design, structural design and maintenance), Health and Safety and many British Standards relating to Mastic asphalt and bitumen waterproofing specifications. The Green Roof Code and interactive Green Roof Guide have been designed to improve the quality of green roofs and thereby impact on the following climate change issues: Flooding - Green roofs reduce storm flow run-off by holding water in the green roof system. The minimum substrate depth of 80mm recommended in The Code means the green roof holds rainwater more effectively, reducing the risk of localised flooding. 38

39 Increasing production of greenhouse gases - Green roofs help maintain cooler buildings - Minimum substrate depths and guidance on the most effective type of vegetation to cool a building reduces the need for artificial cooling within the building. This in turn reduces the buildings electricity consumption and CO2 emissions. The Urban Heat Island Effect - The increased uptake of green roofs will result in cooler towns and cities, thereby reducing the Urban Heat Island Effect. Methodology and dissemination The methodology applied to this project was simple in structure and is replicable in other areas. First the project stakeholders had to be identified and engaged. Then desk based research occurred into the various codes and guidance currently available in the industry. Focus groups and awareness raising events input into this and the key principles The Code would encompass. Stakeholders were then asked to consult on the drafted Code document. This was then disseminated through various activities, with awareness raising events occurring throughout the project. Key stakeholders identified included: Government Bodies (Environment Agency, The Institute of Structural Engineers, Homes and Communities Agency, Natural England) The Green Roof Industry (Manufacturers, Installers, Supply Chain Companies) Local Authorities (Planners/Biodiversity Officers, Building Control) Built Environment Professionals (Architects, Structural Engineers, Surveyors) Specialist technical groups (technical, vegetation and regulatory) were created, containing stakeholders with specific expertise. Consultation took longer than expected due to the differing priorities of stakeholders and number of green roof products on the market. An online portal (similar to that used by Local Authorities on feedback of planning policy) was used to gain feedback on The Code from stakeholders, particular local authority members who found it hard to input due to time restrictions. In addition to this The Constructor Group became the project s media partner, allowing information to be disseminated to a larger, relevant audience through articles and editorials. Press releases were also issued to local media, and industry events were attended, such as Ecobuild (London) and the Greenbuild Expo (Manchester). The project team linked heavily with the National Federation of Roofing Contractors (NFRC), through the sponsorship of a Green Roof Award Category at their Annual Roofing Awards, held to an audience of 1,000 delegates. This was instrumental in disseminating The Code amongst the target audience. The Awards provided the opportunity to promote, celebrate and reward green roofs which conformed to the best practice principles of The Code and Green Roof Guidance. Case studies were of winners and runners up to provide best practice example to the construction industry. A best practice study visit to Stuttgart (Germany) with stakeholders in year 1 of the project allowed stakeholders and the project team to see first-hand the impact that local government policy can have on increasing green roof coverage. The final Code document was celebrated at a seminar delivered to key stakeholders and interested parties in late The Environment Agency together with the Homes and Communities Agency fully endorsed The Code and added their logos to the final publication. Natural England provided significant input at the consultation stage, which was incorporated into the final documents. Benefits and specification of green roofs A common green roof build up consists of: Roof resistant barrier Protection layer Drainage layer Filter layer Growing medium Vegetation Appropriate components i.e. outlet inspection chambers, 500mm vegetation barrier 39

40 Comparison of a traditional and green roof: Green Roof structure: 40

41 The Code reinforced the need for minimum standards in relation to green roof specification, design, construction and maintenance to ensure maximum benefits were gained in relation to climate change mitigation and mitigation. The most important aspect of green roof design noted in The Code is that the depth of green roof substrate used is not less than 80mm. This is essential to ensure the long term sustainability of the roof in terms of water retention and biodiversity value. Key factors covered in relation to the specification of plant layers include plant water storage capacity, plant architecture (e.g. leaf size, shape and coverage) and physiology (e.g. transpiration tendencies etc) will affect the roof s performance and its tolerance to drought, wind, light, shade and pollutants. Different green roof aspects and climate aspects will expose vegetation to different climates. If the principles of The Code are followed maximum benefits will be gained in terms of: Temperature reductions in urban environments due to increased thermal mass and cooling affect of vegetation Reductions in flash flooding risks due to the greater capacity to hold rainfall. The quality of storm water run-off was also improved due to the substrates filtering capacities in line with EU Water Framework Directive. Roofs built for this purpose would use plants with a high water storage capacity such as sedums Improving air quality. Increased space for biodiversity, in line with the Natural Environment and Rural Communities Act, Biodiversity Duty and the Natural Habitat legislation Natura, Greater substrate depths provide opportunities for more varied planting and more microhabitats. A roof seeking to improve local biodiversity (e.g. habitat creation) may require a specific mix of indigenous species (often selected by an expert ecologist). The key factors above demonstrate that different types of green roofs, substrate and vegetation will support different habitats and species. Biodiverse roofs can be designed to mimic various habitats. They can be especially important as a tool to recreate the plant communities that are sometimes lost when redevelopment takes place. These Brownfield sites are often the most biodiverse. The best designs may often be ones that support a range of habitats for wildlife, including substrates, microhabitats and substrate depths. Green roof designs should vary in different parts of the UK to meet the objectives of local Biodiversity Action Plans. How Dr Stephen Brenneissen recommends varying substrate depth to encourage invertibrates. 41

42 The Code also supports key existing legislation such as: The Kyoto Protocol, EU countries are legally bound to cut their greenhouse gas emissions to 8% of 1990 levels by 2012 EU Energy Policy (Jan, 2007) - The European Commissions aim to reduce green house gas emissions by 20% by 2020 The European Strategic Energy Technology Plan (2006) which sets out the development of technologies relating to low-energy buildings, energy conservation and carbon capture 2002 Directive on Energy Performance of buildings - promotion of improvements of the energy performance of buildings within the EU EU Water Framework Directive including flood policy and urban waste water directive which aims to reduce declining water quality European Floods Directive Clean Air Act for Europe, May CAFÉ Microclimate: The orientation of the building and that of any surrounding buildings in the vicinity will affect the shading levels on the roof, whilst also affecting wind levels. In terms of economic benefits of constructin a green roof to the principles of The Code, it can lead to cost savings in relation to reduced energy used due to the reduction in artificial cooling required. Developments featuring a green roof also demand higher rents and open up access to greener clientele due to outwardly demonstrating commitment to sustainability issues. The supporting Developers Guide to green roof document demonstrates that there is a reduction in void periods for those renting out buildings with green roofs. The water attenuation capability of green roofs to help reduce peak flow rates and l rainwater runoff, reducing the drainage infrastructure and water storage requirements of new developments. Research has shown that the cooling effect of a green roof leads to an increase in the efficiency of renewable forms of technology such as Solar Thermal and Photovoltaic (PV) Panels. Green roofs have social benefits as they create amenity space which can be used for recreation, community gardens or wildlife habitats. This has been shown to improve health and wellbeing. It is hoped that the awareness raising and dissemination activities of the project will lead to greater green roof uptake and job creation in the green roof sector to meet demand. After-LIFE To ensure its longevity Groundwork Sheffield has committed to keeping The Code and supporting documents available freely in the public domain on Groundwork Sheffield and key partner websites. The NFRC have agreed to be custodians for The Code, committing to updating in for the next 5 years in partnership with Groundwork Sheffield. The NFRC have disclosed that The Code has been the most heavily downloaded resource they have ever had on their site - such is the demand for and uptake of the document. In addition, a new website has been launched specifically to host the Green Roof Guide, a web based format was deemed most appropriate - due to its interactive nature. This can be found at GRO and GRACC have also been approached by the British Standards Institute (BSI) which is keen to develop a formal British Standard for green roofs based on The Code, which will highlight the document event further. Groundwork Sheffield has committed to producing case studies on the 2011 NFRC award winners which will be disclosed in These will be displayed on the project website. We have also committed to update the 5 case studies already established with key performance characteristic set out in section 3.1 of The Code, if provided by the installers. There are also plans to improve explanatory text regarding habitats in the online version of the Green Roof Guide. 42

43 5.4.3 After-LIFE Communication plan Whilst GRACC formally ends on 31st December 2011, a strong relationship has been built with GRO which includes members of the NFRC. As a result, GRO have committed to update The Code and guidance notes annually for 5 years into the future and to ensure their continued availability for free via the NFRC website and partner websites. This was confirmed formally at the GRO Meeting on 31st August The first annual review of The Code will take place on the 2nd of April at the annual GRO meeting (The agenda for the meeting can be viewed in appendix V). This will ensure that the commitment of involvement of partners is monitored regularly. The NFRC holds the master Code document and this updated all linked copies As a result, The Code will remain freely available into the future. The main threat to achieving the overall aim of GRACC is that awareness of The Code will lessen over time or partners may not fulfil their commitments to The Code. Groundwork Sheffield has committed to keeping dedicated websites hosting The Code live and up to date for the next 5 years along with links to these sites from the Groundwork Sheffield website. Groundwork Sheffield and The Green Roof Centre will continue to promote The Code and supported documentation at all events they attend. We aim to continue disseminating The Code and guidance documents to a range of appropriate level bodies such as Local Government Association, Royal Town Planning Institute, Institute of Environmental Management and Assessment (IEMA), and the Institute of Ecology and Environmental Management (IEEM). In the meantime, members of GRO and GRACC have also been approached by the British Standards Institute (BSI) which is keen to develop a formal British Standard for green roofs based on The Code. To date, this approach has not been taken up by GRACC due to the following: A British Standard document would not be freely available and is likely to dissuade people from purchasing the document. Not all sections of the green roof industry supply chain fully engage with British Standards which would ultimately stifle dissemination. Creating a British Standard would require additional investment which is currently not forthcoming from any of the partners involved. GRO do not feel that going down the route of a British Standard would increase the overall quality of green roofs over and above that which application of The Code can. In addition to The Code itself, the NFRC and GRO members are in the process of developing training for installers and maintenance teams. The training will use The Code as a foundation and look to develop best practice installation and maintenance methods. Due to current changes in the UK planning framework the original Supplementary Planning Document produced through the project required revising. ECUS Ltd, a local environmental consultancy have been appointed to research into the new system and provide an updated guidance note if appropriate. Groundwork Sheffield have committed to making this available on their website if produced. This will provide further links to Local Authorities to build on in the futures. Groundwork Sheffield has committed to producing case studies and a press release on the 2011 NFRC award winners which will be disclosed in These will be displayed on the projects website. We have also committed to update the 5 case studies already established with key performance characteristic set out in section 3.1 of The Code, if these will be disclosed by installers. There are also plans to improve explanatory text regarding habitats in the online version of the Green Roof Guide 43

44 Appendices A - Project GANTT chart B - Stakeholder map GRACC C - Tasks completed by team D - Habitat Action Plan E - Supplementary planning F - Mapping excercise G - Stuttgart visit write-up H - Awareness raising activities I - Green Roof Guide J - DIY Guide to green roofs K - Case studies L - Life consultation press release M - Project launch press release N - Judging pannel for NFRC 2010 O - Local authorities consulted P - Example article Q - Organigramme R - Overview and evaluation S - Management structure T - Developer s Guide U - NRFC Awards press release V - GRO meeting agenda W - Attendees to GRO event X - Glossary of terms Y - GRO specialist groups Z - Code presentation 44

45 Appendix A Project GANTT chart 45

46 46

47 Appendix B Stakeholder map GRACC 47

48 48

49 Appendix C Tasks completed by team 49

50 Appendix C: Examples of tasks completed by the project team overt the course of the project Project Management (Wendy Bussey 4.5 days a week and Fergus Beesley 3 days a week): Meetings and seminars attended (including key stakeholders: GRO, Livingroofs.org, Homes & Communities Agency) Monthly team meetings have been held with the rest of the project team. Established reporting systems (records of expenditure, progress reports, collation of output evidence) Monthly finance meetings have been held with the Finance Manager and Groundwork Executive Director. 7th January- Discussions had with the University of Sheffield to agree sub-contract agreement for expert advisor time. 15th January - GRO meeting held in Sheffield to mark start of GRaCC project 11th February - Presentation on the Code to Melton Council 3rd March - LIFE launch meeting, London 5th March - Presentation on the Code at EcoBuild, London 17th March - meeting HCA & agreeing co-financing arrangements 18th March - Task Group Meeting (UoS and GWS) 19th March - awareness raising event held with the GBSO (Green Business Support Organisation). This is an organisation for environmental practitioners across Yorkshire & The Humber region) 20th March - Presentation on the Code to the Homebuilding and Renovation Show, Birmingham 2nd April - Presentation on the Code to BALI members, Warwickshire 9th April - Meetings held with the British Standards Institute to discuss accreditation options and costs 14th April - meeting with Beta Technology 29th April - GRO meeting, London 1st May - Presentation to Cotswold District Council 6th May - Manchester Green Roof Programme Launch 15th May - Attend NFRC congress and awards 25th, 26th, 27th May - Attend World Green Roof Congress, Stuttgart 10th June - Eco-transformation workshop with city-region 17th June - Present at Green Build Expo, Manchester 20th June - Project update meeting with Livingroofs.org 20th June - Meeting with NFRA to discuss green roof awards 14th July - Presentation to Yorkshire RIBA members, Sheffield 11th August - Presentation to Unitied Utilities, Warrington Ongoing technical support and input from Beta Technology Production of final report Green Roof Development Officer (Anna Cooper 5 days a week): Attending monthly team meetings Liaising with stakeholders Liaising with Local Authorities research undertaken survey carried out on 21/1/09 Producing Green Roof News and editorials Meetings and seminars attended (including key stakeholders: GRO, Livingroofs.org) 15th January - GRO meeting held in Sheffield to mark start of GRaCC project 29th January - Meeting with to discuss LIFE+ 3rd March - LIFE launch meeting, London 5th March - Attendance at EcoBuild, London 14th April - Meeting with Beta Technology 29th April - GRO meeting, London 19th May - Meeting woth Groundwork Uk to discuss article on LIFE+ 17th June - Present at Green Build Expo, Manchester 11th August - Presentation to United Utilities, Warrington 50

51 Dissemination and network role (Cleo Watts/Paul Jones 3 days a week and Kate Beaumont 2 days a week): Attending REY events Arranging and attending the above meetings with the Project Manager Drafting press releases and editorials Providing text for website and e-bulletin Collating Green Roof News Creating marketing materials for conference and exhibitions attended. Admin (Mandy Jeffrey 3 days a week): Collating timesheets Processing invoices and payment Arranging meetings Bookings for awareness raising events Expert advisor (Jeff Sorrill and others as required): Co-ordinating specialist task teams Delivering training GWUK green roof champions training, GWUK landscape architect training: 11th June, general training Dearne Valley Eco-vision support Presentations at a wide range of events and workshop Technical advice Monitoring Officer ( Kate Beaumont 3 days a week) Providing and maintaining effective financial and monitoring systems Recording evidence of expenditure against budget headings. Recording deliverables and milestones alongside gathering the evidence that the deliverable and milestones have been achieved (e.g. delegate attendance, correspondence, copies of publications etc). Establishing audit trails, update financial records, produce statements of expenditure & income and re-profile in the case of any significant changes to the budget. 51

52 52

53 Appendix D Habitat Action Plan 53

54 Habitat Action Plan Guidance Questions Design & Characteristics Management & Maintenance Vegetation Target Species 54

55 The Habitat Action Plan Guidance is aimed at those commissioning and installing green roofs such as planning policy staff. It supports Local Planning Authorities to put in place policy which will support biodiverse green roofs. It provides the reader with the latest research and information about designing roofs rich in flora and fauna. It stresses the environmental benefits of sustainable green roofs and clarifies the relationship between biodiversity and BREEAM points when in rooftop situations. 55

56 Design & Characteristics 1. Have you considered a substrate depth of at least 80mm over the roof? Substrate is a key factor in creating a biodiverse roof. Substrates should be nutrient poor, well drained and varied in depth to provide the suitable conditions for species diversity. 80mm depth is the recommended minimum depth to support biodiverse green roofs. By varying your substrate depth and composition across the roof, you will help to encourage different species of flora and fauna. 2. What material is your substrate made up of? If possible, you should try and use screened and sorted locally sourced aggregates and soils for the substrate. This will help to recreate local habitats for specific species or variety of flora and fauna. This way, you are also re-using otherwise wasted construction materials. Do make sure the materials are not contaminated or from a site where invasive or unwanted plant species have been present (e.g. Japanese Knotweed). 3. What percentage area of your roof have you covered with substrate? The higher the percentage of roof that you cover with substrate, the greater chance there is of encouraging a variety of flora and fauna to populate the roof. As a minimum, for a biodiverse green roof you should consider covering 40% of the roof with substrate. The actual percentage coverage feasible will depend on the loadbearing, depth of substrate possible, size of roof, space available and pitch of roof. 4. What establishment method for planting has been used on the roof? Whilst pre-grown mats can be useful for some green roofs, encouraging higher levels of biodiversity requires considering the following establishment methods: seeding, plug plants (i.e. plants which have been pre-grown before planting) and spontaneous colonisation. This should be considered at the design stage of the green roof and be linked to the vegetation and species being targeted on the green roof. 56

57 Management & Maintenance 5. Do you have a management plan in place for the green roof? The choice to develop a biodiverse green roof or allow for spontaneous colonisation is not necessarily the easiest or least expensive option. A clear plan should be developed for a biodiverse green roof which includes: primary aims and objectives (e.g. in relation to enhancing local biodiversity), description of habitat to be achieved and species to be targeted. The plan should be shared with the project team early in the process. 6. Do you have a maintenance programme in place for the green roof? Biodiverse green roofs do require ongoing maintenance, although less frequently compared to an intensive green roof (e.g. a roof garden). Maintenance plans should be appropriate for the level of biodiversity being strived for on the roof. Maintenance may include: removing unwanted plant species from the substrate, altering features to increase biodiversity and also monitoring and measuring of species by specialists. 7. What level of level of human interference will occur on the green roof? Lower levels of human interference will encourage greater biodiversity by allowing uninterrupted growth and colonisation periods on the green roof. Whilst some green roofs are designed to allow for use by humans (such as roof gardens and terraces), minimal human interference will create a more natural and uninterrupted environment with greater potential for biodiversity. 8. What are the principal aims of your biodiverse green roof? It is important to establish from the outset the primary aim of your biodiverse green roof. For example, are you aiming to mimic a local habitat or to recreate a wasteland community that may have been lost through the development? Alternatively, green roofs can recreate habitat for some endangered species by focusing on a specified species habitat. Specialist ecologists may need to be contacted to establish feasibility. 57

58 Vegetation 9. Are the main plants you are using suitable for the area and the roof? Whilst native plant species (and those that are covered in BAPs) are usually preferable, consideration should also be given to non-native species with recognised biodiversity value. However, growing conditions on a roof can vary (e.g. different wind speeds, temperatures and sunlight), and thus habitats on the ground cannot always be mirrored on roofs, green roofs should be planned to take account of these variances. 10. Are you using plants that will encourage biodiversity? Laying lawn (turf) or pre-grown mats with minimal substrate across an entire green roof will limit the range of biodiversity found on the roof. Greater biodiversity will occur from a mixture of planting and habitats, and varying the planting across the green roof with features (see Target Species section). 11. How many habitats will your green roof support? Smaller green roofs should focus on fewer habitat types each covering a larger percentage of the roof. Larger green roofs may be able to host greater number of habitat types. Types of habitat can be chosen from local BAPs or existing HAPs for the area (e.g. Urban Common), and should be appropriate to local conditions. A habitat mosaic is an area or site comprised of multiple habitat types, and should encourage greater biodiversity. 12. Do your chosen habitats and vegetation meet the need of your targeted species? If you have chosen to design and develop a specified species habitat, it is important to consider the type of habitat and vegetation that will be required to support the target species. In this instance in particular, the habitat must be given plenty of time to become established and human interference should be minimised once planting is complete in order to encourage the introduction of the species. 58

59 Target Species 13. Are the chosen target species appropriate for the area and the roof? Habitats can be targeted to support certain faunal groups that may be listed on UK or local BAPs. This can add an interesting element to the development of your biodiverse green roof as it is sometimes possible to create habitats that will support endangered species. Detailed consideration and input from specialists will be required in order to ensure the feasibility of attracting target species and creating a habitat in which they will prosper. 14. Have you considered using features on the roof to enhance biodiversity? Certain features on green roofs can help to increase biodiversity in general, as well as supporting target species. These can include: piles of bricks, stones, or logs, pipes, mounds of sand or limestone and wet areas. The inclusion of bat or bird boxes, bird perches and invertebrate/bee houses can also encourage biodiversity. 15. How will your green roof connect to other areas that support target species? It is important to consider how your green roof links to other areas and habitats that support target species in the area. Green roofs may not be able to replicate habitats at a ground level, but they can provide a stepping stone for wildlife or species and offer connectivity for target species in an area. It is important to consider local BAPs and HAPs and existing projects for target species in your area when designing your green roof. 16. How will you monitor and measure the success of the habitat for the target species? If a green roof has been designed for a specified target species, it is important to measure the success of the roof to attract the species on an ongoing basis. This may be carried out by specialists who will be able to identify the target species. If the green roof is on a building open to the public, this can be used as an excellent communications tool and could be included on the website or on notice boards in the building. 59

60 60

61 Appendix E Suplementary planning 61

62 Green Roof Supplementary Planning Document Guidance Introduction a. What is an SPD? A Supplementary Planning Document (SPD) is one of the material considerations that can be taken into account when determining a planning application. It forms a part of the Local Development Framework (LDF) and is intended to expand or add details to planning policies in the Development Plan Documents (DPD). An SPD is important in helping the local authority make decisions about planning applications. b. Aims of this SPD Guidance To provide clear advice to developers, builders, architects, contractors, planners, communities and design professionals on green roofs To ensure that when green roofs are part of a proposed development, they are treated as an integral element of that development rather than an additional extra To set minimum requirements for green roofs on new developments c. How to use the SPD Guidance Section 1 explains what an SPD is and sets out the aims of the green roof SPD. Section 2 provides background and context to the document, providing information on types and benefits of and outlining the relevant policy framework. Section 3 sets out the green roof design requirements and forms the core element of the SPD. Section 4 provides background and supporting information and definitions of terms used in the document. 62

63 2. Background a. Green roofs Green roofs, sometimes referred to as living roofs, are roofs that are purposely planted, cultivated or seeded with vegetation. There are different types of green roof and each type functions differently in terms of the type of habitat provided, how storm-water runoff is affected and their impact on energy usage and thermal performance. There are two main types of green roof: intensive and extensive. Intensive roofs are more like gardens: they have a deep layer of soil and can support a range of plants, shrubs and trees. They provide a rich habitat for wildlife but require regular maintenance. Extensive roofs are low nutrient and low maintenance and are also often designed to be light weight. They do not require frequent maintenance or irrigation and the substrate is usually shallow, typically <100mm. Green roofs provide the following key benefits (these will be expanded on slightly): Reduced storm water run-off Increased roof lifespan Reduced energy consumption Climate change adaptation and mitigation Lessened urban heat island effect Increased biodiversity Improved air and water quality Reduced sound transfer Increased amenity space b. Key drivers and policy framework There are wide ranging policies at local, regional and national level that are associated with green roofs, and which must be taken into account when setting out the SPD. i. Local Planning advice notes Research advice notes Planning guidance notes Good practice guidance Unitary development plans Local development framework ii. Regional Regional spatial strategies (including the London Plan) iii. National PPS1 (Delivering Sustainable Development) PPS9 (Biodiversity and Geological Conservation) PPS25 (Development and Flood Risk) Climate Change Act 2008 Biodiversity Strategy for England Flood and Water Management Bill 63

64 3. Design requirements This section of the SPD gives details on how green roofs should be designed, installed and maintained in order to optimise waterproofing, minimise potential for leaks, maximise water supply to plants and provide enhanced amenity to the building. The following minimum design requirements should be considered: Approval: full details of the green roof construction and specification, together with a maintenance schedule, shall be submitted to and approved by the local authority prior to works commencing on site. Cover: unless otherwise agreed in writing the proposed green roof(s) (vegetated roof system) shall cover a minimum area of 80% of the roof and shall be provided prior to the use of the building commencing. Substrate: unless an alternative specification is agreed the green roof shall include a substrate based growing medium of 80mm minimum depth and incorporating 15-25% compost or other organic material and the vegetation type shall be herbaceous plants. Waterproofing: all green roofs must include a waterproofing system which is leak-tested and certified by the manufacturer/installer, and which should allow for vapour dispersion. Root resistant element: all green roofs must include protection from the plants roots penetrating the building. This can be done by either a chemical in the waterproof finish or a separate layer. 64

65 Appendix F Mapping excercise 65

66

67

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69

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71 Appendix G Stuttgart visit write-up 71

72 Appendix H The UK Green Roof Code (LIFE + project) Fact finding trip report : Tuesday 4th Friday 7th May 2010 In early May 2010, five delegates from the LIFE+, UK Green Roof Code Project undertook a fact finding trip to Stuttgart (Germany) and Linz (Austria), to see first-hand the impact that local government policy can have on increasing green roof coverage. It provided the chance to speak with people at the cutting edge of green roof legislation; to understand more about best practice techniques and the challenges for installing the technology. On arriving at Stuttgart airport, we found ourselves speeding along the extremely efficient tram system, which took us to the door of our hotel within 30 minutes. Once there, we were met by Wolfgang Ansel from the International Green Roof Association. Despite only having been in the country for an hour, we crammed into Wolfgang s car excited to see our first green roof scheme of the day which was Hohlgrabenacker - a new housing development on the outskirts of Stuttgart nestling in-between the tree covered district of Zuffenhausen. On route Wolfgang told us about IGRA and his work championing green roofs within the city. He spoke enthusiastically about ecology and landscape, and of the incentives offered by local government to encourage green roof implementation and sustainable design more generally. At Hohlgrabenacker, we were greeted by the principal Landscape Architect for the scheme; Freddy Diem. As we started to walk around the site, Freddy explained that to minimise the environmental impact of the development, a number of design criteria had been set including the requirement for green roofs, storm water retention and sustainable infiltration. The planners requested that the development achieve the ambitious target of only 20% impervious surfacing, primarily to address the lack of capacity within the existing drainage system. Freddy and his team had achieved this target and were justifiably proud of their efforts. Freddy and Wolfgang continued to show us the rest of the development, pointing out permeable road surfacing, pavements and green roofs, totalling 18,300m2. Green roofs are requested on approximately 80% of the dwellings and must have a substrate depth of 120mm in order to achieve the runoff coefficient of 0.3. Best practice in the UK is between 50 and 75mm, so the findings from Hohlgrabenacker are particularly useful as minimum standards will be drafted as part of the LIFE+ project. As we neared the end of our tour, the rain started to fall and we made our way back to the hotel, looking forward to the busy day ahead. On Wednesday, we were up early and sped off on a tram towards Scharnhausen, an ex army base, which is now home to over 6000 new homes. The site utilises a combined urban water management system complete with green roofs. As we left the city behind, we were amazed at how green the landscape suddenly became - even the tram tracks had low-growing grasses in between them. We stepped off the train to be met by a city planner, who had been heavily involved in developing Scharnhausen and then embarked on a walking tour of the estate. Wolfgang and his colleague helpfully explained the different design features including green roofs, drainage details, swales and gullies. Despite what felt like sub zero temperatures, we braved the outdoors for several hours eager to see and hear how the site had been developed using a fully integrated sustainable urban drainage system with rainwater feeding ponds and children s play areas. We ended the tour inside the town hall, which itself has an extensive green roof. Wolfgang led us out onto the Town Hall roof, for amazing views of green roofs stretching as far as the eye could see - they covered a variety 72

73 of buildings from schools, to supermarkets and offices. Following a hot drink and slice of pizza, we were ready for the afternoon. This session was held in the central municipality offices, and here Wolfgang gave a presentation on how the green roof strategy had evolved in Stuttgart and the aims of the IGRA. We talked about the difficulties and challenges for maintaining quality assurance and the importance of providing incentives to install green roofs wherever possible. Next, Wolfgang gave us an overview of the different green roof policies within different German cities emphasising the importance of locally specific policy drivers. This was extremely useful for our Environment Agency delegate (Tim Andrews), who explained the increasing focus on flood and water management within the Environment Agency s remit. Wolfgang s presentation also included valuable information about how the water runoff co-efficients are generated within the FLL guidelines. Interestingly, unlike the UK, biodiversity is not a big driver for green roofs in Germany. Wolfgang was very keen to know more about the biodiversity aspect of our work and The UK Green Roof Code, so we agreed to send him further information about the roofs we have in the UK. Finally we were introduced to a local Green Party Cllr, who discussed the importance of having a mandatory green roof policy in order to make a real difference in practice. After a long day we were ready for our beds and looking forward to the train journey from Stuttgart to Linz. On Thursday afternoon, after yet another impressive journey by public transport, we arrived in Linz raring to go. We were met by Edmund Maurer, a senior planner within the Municipality of Linz, who has been instrumental in leading the city s green roof policy. Following a tour of the city centre we went for a meal and discussed our plan of action for the next day. Edmund had a full itinerary planned for the Friday and announced that he would be picking us up from the Hotel lobby at 8.00am!. So early on the Friday morning we climbed into the minibus, and were driven to our first site visit of the day. The first stop was to see one of Linz s oldest green roofs - an intensive rooftop garden complete with an allotment and a variety of fruit trees and plants. The roof was on top of a 1950 s block of flats, and across the road from a new housing complex. All these new homes had extensive green roofs and there were even green roofs on the raised entrances to underground car parks - in one case the gardens for the surrounding dwelling sat over the underground car park. Edmund highlighted the difficult issue of policing the quality of green roof installation, pointing to several of the new green roofs which looked stressed and dried out. Again the issue of substrate depth was discussed, and similarly to Stuttgart, Linz is now recommending a deeper substrate of around 110 mm. Next we went to see Linz s biggest extensive green roof - over 25,000 mt 2 (? Please could you let me know the size Edmund - thanks!) spanning a furniture assembly factory owned by the Schachermayer company, in the industrial heartlands. The factory owner generously allowed us to visit the roof area and we roamed across the vast expanse of sedum, while the building s facility manager explained the major driver for the company installing the roof had been the cooling benefits for the space below and reduced air-conditioning requirements. A closer inspection of the plants growing found an abundance of chives and Dusty highlighted a section of the roof which had been repaired and replaced with a different substrate. The result was a lower quality patch of green roof where the sedum looked very stressed. Dusty and the Facility Manager agreed that the substrate in this area had a higher content of crushed brick than the remainder of the roof and as a result was not able to hold enough water. Before leaving the industrial area of Linz, Edmund took us to a nearby Combined Heat and Power plant, which housed a 300 metre tall chimney. Edmund explained that the chimney provided an excellent viewing point from where we could see the effects of Linz s green roof policy on the ground below. Initially we thought Edmund was joking, however we soon found ourselves ascending in a tiny 73

74 rickety elevator towards the tower s viewing platform. At the top we nervously climbed out from the elevator and braced ourselves against the winds to peer over the railings. Once the scary feeling of being 300 metres above the ground had subsided, it was possible to see the impact of the green roof policy immediately. Due to the incremental nature of development within the industrial area, one could effectively draw a line between developments pre 1985 i.e. prior to the green roof policy and those post 1985 i.e. after the policy s introduction. The Schachermayer s green roof stood out like a green sea against the backdrop of grey factories and smoking chimney stacks. After taking in the skyline of the city, we descended and were driven to the Bindermichl Motorway. The Motorway had previously cut through a residential estate - effectively dividing the communities on either side. The housing in the area had grown increasingly undesirable as air and noise pollution from the motorway grew. As the quality of life for local people declined, pressure was put on the local government to address the situation. The response from the local politicians was radical and on a grand scale; - the construction of a park over the motorway. On visiting the park - it looks and feels just like any other park; there are no obvious signs that a dual-level motorway runs beneath the grass and trees. This site visit was perhaps the most inspirational of all - highlighting both the potential for green roofs and the positive outcomes that occur when there is strong political backing for a solution. We came away feeling enthused and motivated by our time spent in Stuttgart and Linz - the findings are of great assistance to the LIFE+, UK Green Roof Code project. The results of robust green roof policies were clearly evident in the developments we saw and the trip gave us valuable insights for developing both green roof policy and minimum standards back in the UK. The trip also emphasised the benefits of joint working between Member States, and highlighted how the experiences and learning gained would not have been possible without the commitment from Wolfgang Ansel and Edmund Maurer. So, this report concludes by saying thank you to Wolfgang and Edmund for dedicating their time and energies to arranging site visits, co-ordinating meetings and exchanging best practice. We look forward to seeing them in the UK! Wendy Bussey (wendy.bussey@groundwork.org.uk ) Project Manager, Groundwork Sheffield

75 Appendix H Awareness raising activities 75

76 Appendix I: Update on Awareness raising activities Awareness raising started from March 2009, The first twelve months were focused primarily on raising awareness of green roofs in general and the need for the Code. People were encouraged to become a consultee by registering on the project webpages (via The Green Roof Centre and Groundwork Sheffield websites). In the second year stakeholder events sought feedback on various chapters and sections of the Code. An online engagement tool was used to engage and raise awareness of the project using the same format as many Local Authorities had used for consulting on their new planning frameworks throughout The code official launch was in May 2011 as part of the National Roofing Awards with a project summary being held in November 2011 to launch and celebrate the green roof guidance. A best practice study visit to Stuttgart (Germany) and Linz (Austria) occurred in the 2nd year to see first-hand the impact that local government policy can have on increasing green roof coverage. It provided the chance to speak with people at the cutting edge of green roof legislation; to understand more about best practice techniques and the challenges for installing the technology. Participants at events Total for 3 years: 450 (approx 13 per event) Achieved in year 1: 280 Achieved in year 2: 2,120 Achieved in year 3: 137 Achieved to date: 2,537 Awareness Raising events Target for 3 years: 36 awareness raising events (4 in each region) Achieved in year 1: 7 Achieved in year 2: 15 Achieved in year 3: 13 Achieved to date: 35 Overview of events held Output Duration Attendees Location Evidence Ecobuild 3rd - 5th March days (short seminars across the period) 120 London Presentation and photo in appendix photos G Cotswold Council 1st May hour Seminar 23 South West Please see appendix U for the presentation from the event. Manchester Green Expo 18th June hour presentation 35 North West Presentation in appendix I House building and Renovation Show, Birmingham 30 minute Presentation 18 West Midlands Please see appendix X for presentation Doncaster - Green Business Support Organisation event 30 minutes 34 Yorkshire & The Humber See appendix O for a copy of the publicity material surrounding the event. 76

77 Lemington Spar - BALI event 1 hour 15 West Midlands See appendix T for the agenda from the event RIBA event in Sheffield 2 hour seminar 20 Yorkshire & The Humber Please see appendix R for an evaluation sheet from the event. Green Roof CPD Workshop with Sheffield Hallam University 2 hour CPD 15 Yorkshire & The Humber See appendix P for the agenda from the event TOTAL 305 Year 2 Event Duration Purpose Date Attendees Location Evidence Introduction to green roofs course 1 day Awareness raising 10th Sept N/A Spreadsheet containing contact information of 5 people (attendees) Presentation given at East Midlands Expo day Awareness raising 8th Oct Leicester Presenter materials and event flyer Introduction to green roofs course 1 day Awareness raising 9th Oct ICOSS, Sheffield Delegate list Delivery Design Quality Awards 12 hrs Networking 9th Oct Barnsley Networking contacts North East Derbyshire District Council 1 day Awareness raising 13th Oct 2009 N/A N.E. Derbyshire Life+ Outputs Folder Association of Wildlife Trust Consultancies 2 days Seminar delivery 3rd and 4th Nov Sheffield Flyer Greater Manchester Forest Network 2 hrs Seminar 17th Nov delegates, 27 businesses Manchester Event materials Editorial for Green Build News Magazine October 2010 issue n/a Press 8th Jan 2010 n/a n/a Article Sustainable Construction inet 1 day Seminar 2nd Feb Nottingham Delegate list Digging Deeper into Green Roofs 1 day Awareness raising 9th Feb Sheffield Event materials 77

78 Green Roofs awards judging panel 1 day Panel meeting 25th Feb London Panel list appendix H EcoBuild conference 3 days Networking event 2nd, 3rd and 4th Mar London Life+ Outputs Folder Green Roof Safari (for Festival of Social Science 1 day Awareness raising 17th Mar Sheffield Sheets with names of attendees and The Festival of Social Science booklet Roofing Awards day Awareness raising 14th May ,000+ London 2 letters regarding the awards and photos Green Build Expo day Awareness raising 26th May Manchester Delegate list Total 2,120 Year 3 Event Duration Purpose Date Attendees Location Evidence Groundwork Lancashire 1 day Green Roof training 2nd Feb Wigan Presentation U3A Gardening Group Sheffield 2 hours Awareness raising 8th Feb Sheffield Presentation EA/Derbyshire County Council 2 hours Awareness raising 10th Feb Matlock Attendance sheet EA/Derbyshire County Council 2 hours Awareness raising 25th Feb Matlock Attendance sheet EcoBuild conference 1 day Networking event 1st Mar London Life+ Outputs folder University of Sheffield Council 1 hour Awareness raising 2nd Mar Sheffield None IStructE event 1 hour Awareness raising 16th Mar Wakefield Attendance sheet Scott Wilson 1 hour Awareness raising 18th Mar Chesterfield Attendance sheet Roofing Awards 1 day Awareness raising 20th May Brighton 2 letters regarding the awards and photos Yorkshire Water 2 hours Awareness raising 25th Jul Bradford Attendance sheet NFRC Event 2 hours GRO Code session 27th Jul London Presentation 78

79 Overview of the code 3 hours Disseminate the code 16th Nov Sheffield, COSS Sign in sheet Green roof training East Midlands Landscape Institute 2 hours Training 16th Nov Nottingham Attendance sheet Total 1,437 79

80 80

81 Appendix I Green Roof Guide 81

82 The Green Roof Centre 82

83 Green roofs perform a vital role in helping cities adapt to the effects of climate change by reducing the need for artificial cooling in hot weather and attenuating or capturing rainwater runoff, as well as providing a range of habitats for urban wildlife. These guidelines detail the rules, regulations and legislation for building green roofs in the UK. 83

84 Contents 06 Who is this guidance for? 07 What will this guidance NOT cover? 08 What are green roofs? 10 Types of green roof 14 Green Roof Structure 16 Benefits of green roofs 17 Increasing roof lifespan 17 Climate change mitigation 18 Climate Change Adaption 18 Lessening the Urban Heat Island effect 19 Increasing Biodiversity 20 Improving air and water quality 20 Reducing sound transfer 21 Amenity Space 22 Design Considerations 27 Key technical design requirements 30 Access Requirements 31 Considerations dependent on the green roof being new-build or retrofit? 34 Construction Practice 36 Biodiversity & Planting 46 Maintenence 50 Glossary of green roof terms 05 84

85 85 06 Who is this guidance for? This guide will help anyone who is considering, designing, specifying, installing or maintaining a green roof or those involved in the strategic planning of green infrastructure. Green, living and intentionally vegetated roofs are becoming more common in the UK. They provide many benefits to the occupants of buildings, as well as to the local setting. Green roofs are one of the most readily accessible sustainable technologies available to the construction industry. They can be included as part of new buildings and may also be retrofitted to existing buildings. What will this guidance NOT cover? This guidance does not cover certain technical areas of green roof technology such as drainage flow rates, growing medium performance criteria or waterproofing. If you require technical information of this type please download the English language Guidelines for the planning, execution and upkeep of green roof sites 2008 from the FLL website: FLL - Forschüngsgesellschaft Landschaftsentwicklung Landschaftbau (Landscape Research, Development and Construction Society). It should be remembered that although green roof technology is relatively straightforward, it is possible for people who are unfamiliar with the technology to make mistakes or miss opportunities to maximise the benefits. All parties using this Guide and who require technical information should have a copy of the GRO Code: and the most recent version of the FLL Guidelines: 07 For the purposes of this guide: a living or green roof is; a roof, deck or other structure onto which vegetation is intentionally grown or habitats for wildlife are established.

86 What are green roofs? A green / living roof is a roof onto which vegetation is grown intentionally or wildlife habitats are established. There are different types of green roof and it is important to understand that each type functions and looks different. This is because each green roof is unique and provides a different type of habitat, water storage capacity and energy saving potential. Green roofs can be extensive - implying shallow substrate and load nutrition, through to intensive - similar to roof gardens. The 2011 GRO Code provides UK specific green roof recommendations. Grass Roof in Oswego Illinois, USA. Greg Robbins It is estimated that there is at least 200 million m² of roof space in the UK, which could be greened with little or no modification to the roof structure. Turf roofs were common in northern Europe, but decreased in popularity as the industrial revolution progressed. 43% of German cities provided incentives for green roof installation. Other countries in Europe such as Switzerland and Austria also have a long tradition in using green roofs. More recently Canada, America, Japan and Singapore have experienced a growth in green roof uptake. Living Roofs and Walls Technical Report: Supporting London Plan Policy

87 Types of green roof Green roofs are classified according to their depth and maintenance requirement. The following names for different green roofs have been adopted by the construction industry: Type of green roof Description Extensive Less than 100mm substrate depth, and not usually irrigated Low maintenance Limited water holding Limited biodiversity potential Includes pre-grown vegetation mats or substrate. Lightweight extensive Super lightweight Low biodiversity potential Low water holding Includes pre-grown vegetation mats Sometimes irrigated No additional substrate Open substrate. Consists of thin (12mm) drainage board, a filter fleece/water retention mat and pre-grown vegetated mat about 25mm in thickness Minimum loadings Sometimes irrigated Practical for some retro-fits Limited vegetation diversity Tendency to dry out. Intensive Semi-intensive Over 200mm substrate depth, intensive maintenance requirement Sometimes irrigated Lawn or roof garden Amenity Space Water attenuation and some biodiversity can be achieved. 100mm to 200mm substrate depth, moderate maintenance, wider range of plants Sometimes irrigated Rainwater attenuation Supports vegetation Slightly higher maintenance. Biodiverse / wildlife (extensive) Supports particular species or group of species Natural colonisation is encouraged Limit level of human interaction Focus on biodiversity value. Roof gardens / podium decks Intensive and well understood Outside scope of this document. These definitions are not always clear cut and it is possible to have green roofs which have characteristics of more than one type, e.g. a 200mm deep substrate which still has low maintenance requirements

88 Biodiverse & Wildlife Extensive 100mm 60mm - 80mm Semi-intensive 500mm Varying depths increases biodiversity, attracting wildlife including birds and insects. 100mm 80mm - 200mm 500mm Intensive For a green roof to flourish it must have: Sunlight Moisture Drainage Aeration to the plants root systems Nutrients 100mm Roof Garden min 200mm The green roof system build-up can consist of: Type B Substrate: Type A 500mm Root resistant material Moisture retention/protection layer Drainage layer Filter layer Growing medium Course substrate for drainage if deeper than 400mm

89 Green Roof Structure The conditions of each individual site must be considered before construction begins, drawing on the skills of specialists: Plant Level Substrate drainage engineers for the hydrological aspects ecologists for the biodiversity elements landscape architects for the overall layout Filter Sheet Drainage Layer Protection Mat Root Barrier Water-proofing* Roof Construction Ideally each green roof is bespoke to different site conditions and local climate. Therefore, designing green roofs to take into consideration both the client s needs and local microclimatic and bioregional factors will result in a better and more sustainable solution. *If the water-proofing is not root-resistant, a root barrier should also be used. Most extensive green roofs, and many intensive green roofs, are supplied as complete systems, which include all components for green roof construction from the insulation and waterproofing membrane to specialist soil mixes and vegetation. These all-in-one systems are useful in many applications, particularly where there is limited flexibility in terms of structural capacity as pre-made systems have a verified saturated weight. However, some suppliers of green roof systems may be able to supply and provide data for individual components which can allow for the possibility of bespoke designs

90 Benefits of green roofs Increasing roof lifespan Green roofs provide numerous benefits. By considering each benefit at the earliest stages of design it will be possible to create a multi-responsive green roof. Flood Reduction An established green roof will significantly reduce peak flow rates and total rainwater runoff compared to a conventional roof. Green roofs store rainwater in the plants and substrate and release water back into the atmosphere through evapotranspiration and evaporation. Roof surfaces are constantly under attack from ultra-violet light and temperature change. The original green roofs in Germany in the 1880s were created when bitumen was covered with 6cm of sand, which colonised naturally with vegetation. This sand covering was to protect the bitumen from fire, however the covering was found to extend the life of the waterproof layer. Green roofs have now been shown to double, if not triple the life of waterproofing membranes. Climate change mitigation In summer, green roofs can retain 70-80% of rainfall and in winter they retain 10-35% depending on their build-up. Generally, the deeper the substrate the greater the average annual water retention. Where green roofs are used on a new development, it is sometimes possible for cost savings made on drainage to be used to offset the additional cost of the green roof installation. Buildings are responsible for ~50% of the UK s CO 2 emissions. A high proportion of these emissions are from heating and cooling. Reducing the energy consumption of the UK s buildings will reduce their contribution to climate change. Green roofs can significantly reduce the cooling load of a building, resulting in reduced air cooling requirements and therefore reduced energy consumption and associated output of atmospheric carbon. The UK spends more money artificially cooling commercial buildings in summer than it does heating them in winter. Green roofs have been shown to impact positively on a building s energy consumption by improving its thermal performance, this varies depending on the weather. Traditional Roof Green Roof Poorly insulated roofs, as found on many existing buildings, will lead to overheating of spaces beneath them during the summer, and excessive heating demand during the winter. By retrofitting green roofs, both air conditioning and heating usage is decreased

91 Climate change adaptation Increasing Biodiversity Green roofs are one of the most effective ways of combating the urban heat island effect and will therefore be part of the raft of future measures designed to help cities adapt. Lessening the urban heat island effect During the hot summer of 2003, night-time temperatures in London reached 9 C higher than outlying rural areas. Different types of green roofs, substrate and vegetation will support different habitats and species. Biodiverse roofs can be designed to mimic various habitats. They can be especially important as a tool to recreate the pioneer (wasteland) communities that are sometimes lost when redevelopment takes place. Within urban areas, it is very often neglected brownfield sites that are the most biodiverse. The best designs may often be ones that support a range of habitats for wildlife, including substrates, microhabitats and substrate depths. Green roofs have very different thermal qualities to conventional roofs. They tend to reflect more of the sun s rays and shade and insulate the underlying structure. The evaporation of water from the soil and transpiration of water from leaves cools the roof. Green roof designs should vary in different parts of the UK to meet the objectives of local Biodiversity Action Plans. Green roof thermal benefits. Shade, albedo, evapotranspiration How Dr. Brenneissen recommends varying substrate depth to encourage invertebrates. Stephan Brenneisen, ZHAW

92 Improving air and water quality Amenity Space The urban heat island effect exacerbates ground-level ozone production, which is formed by a reaction between volatile organic compounds and nitrous oxides catalysed by heat and sunlight. It is classified as a pollutant and is the principal component of smog. Green roofs can improve local air quality through mitigation of the urban heat island effect. A living roof can also help to remove airborne particles, heavy metals and volatile organic compounds from the local atmosphere. As these contaminants are retained by the green roof itself, their infiltration of the water system through surface runoff is lessened, in turn improving local water quality. Reducing sound transfer Designing green roofs for people to access either physically or visually is a great way to get vegetation and some habitat types into the built environment. Whether designed as a roof terrace with paving and raised planters for full access by building occupants or the general public, or high level meadows of wildflower with limited access. People will feel a benefit from being able to access the area. The Fukuoka City Hall is a great example. By extending the vegetation up the back of the building, the cities only park was almost doubled in sizes. The terraces on the back of the building are fully accessible to the public and provide a great oasis in a city of glass and concrete. Rain hammer on some deck roofed buildings, including schools, have been concerns for building designers for some years. Sound escaping from industrial process and other noise processes can also cause issues within local communities. The build-up of organic material within a green roof significantly reduces noise transfer through a roofs structure. Fukuoka City Hall, Japan

93 Design Considerations a) Access and Fire Risk Access As with all roofs, and especially flat roofs, maintenance is required and therefore access must be considered. All green roofs require some degree of maintenance. LOW maintenance should not be interpreted as NO maintenance. Extensive green roofs require less maintenance than intensive roofs, but there is still a requirement to clear gutters and unwanted vegetation every year. Fire Risk First modern green roofs were installed as fire prevention measures. Although experience in Germany has shown that the risk of fire is small, dry vegetation on green roofs does have the potential to catch alight following prolonged hot weather. The following measures are recommended to be put in place to reduce the risk of fire: Vegetation barriers (intentionally un-vegetated strips) of pebbles (20mm - 40mm) or paving (concrete) at 500mm wide to all roof penetrations and in front of all up-stands Pebble or concrete paving in the vegetation at every 40m run, with a minimum width of 1m or a 300mm high fire wall Tests in Germany (DIN ) have demonstrated that extensive roofs are unlikely to be ignited by sparks provided that the substrate base is a minimum of 30mm and contains no more than 20% organic content. Therefore it is recommended that green roof substrate does not contain more than 20% organic content. b) Management of Design Guarantees If the green roof is bought as a package from a reputable firm and fitted by approved contractors, guarantees against faulty construction will be provided. Some green roof systems come with a guarantee of up to 20 years to cover defective product or workmanship. Manufacturers and Supply There are an increasing number of green roof component suppliers in the UK. Look for products which have guarantees and include the supplier in the design process as they will advise on options, loading, drainage and thermal performance. Planning Consent/Permission Incorporating a green roof into a development may gain support which can help to secure planning consent. It may be possible to retrofit green roofs on certain buildings without planning consent, although the planning authority should be consulted if there is doubt. Vegetation barriers are kept clear of encroaching plants by routine maintenance

94 c) Roof Structure Outlet and Downpipe Requirement There should be a minimum of two downpipe outlets per roof as a precaution against blockage. All outlets should be protected by an inspection chamber and surrounded by a pebble vegetation barrier to prevent plant encroachment. A green roof results in a reduction in total runoff volume and peak flow. The reduction in peak flow depends on the intensity of the rainfall and the level of saturation of the substrate before the rain began. Roof Pitch Formula Structural Capacity Structural loads on the roof depend on the type of green roof chosen and a structural assessment is always required. It is important that calculations incorporate the load when the substrate is saturated, as this will be when the loads are greatest. d) Design Factors Biodiversity It may take a while for a green roof to create the appropriate habitat, It cannot be assumed that a green roof will be immediately successful in conserving key species. It should also be noted that green roofs cannot replicate all habitats that occur at ground level. Certain species of plant require deep soil or shelter which cannot be feasibly created at roof level, and some soils which occur at ground level may be unsuitable for inclusion on a green roof build-up. Irrigation Extensive (including biodiverse) green roofs do not usually require irrigation, although they are often watered during the establishment phase (the first 4 to 6 weeks after installation). Semi intensive green roofs should not need to be watered unless there is a prolonged period (usually defined as six weeks) without rain. Pitch of the Roof Any pitch of roof can be greened, to the point where the surface is vertical. Greening surfaces over 45 requires technology closer to that used for living walls, outside the scope of this document. In order to green steeply pitched roofs, more complicated designs and installation methods are required. Roofs from flat (~3 ) up to 10 can be greened with standard green roof products. Intensive green roofs are often irrigated. Deeper substrates are less vulnerable to drying out as they can store more rainwater, but the plants are more water dependent, so irrigation can be necessary

95 Rainwater Harvesting Storm-water runoff from a green roof is reduced compared to a traditional roof. However, rainwater can still be collected from a green roof and used for any non-potable applications. Water may be discoloured with leachates from the green roof substrates, however the colour can be used as a good indicator of the building s environmental credentials. Where rainwater is harvested from green roofs, fertilisers should not be used. Solar Thermal and Photovoltaic (PV) Panels On roofs, both solar thermal and PV panels can be combined effectively with green roofs. It has been shown that the cooling effect of a green roof leads to performance improvements from a PV system mounted on A-frames, as the roof is cooler and the PV cells work at a higher efficiency. Key technical design requirements Waterproofing The most important element of any roof is that it is water resistant to ensure the integrity of the building is not compromised. The waterproof component of the roof must be confirmed as being sound before installation. A green roof should be installed over a root barrier, which can be incorporated into the waterproofing itself or may consist of an additional membrane on top. Up-stand Details Roof perimeters, up-stands, outlets and protrusions through the roof should be protected by an un-vegetated area of 20mm - 40mm with rounded shingles or paving slabs. This should be the same depth as the substrate and no less than 500mm across. Diagrams to show the required un-vegetated area of any green roof. 500mm 500mm Outlet Inspection Chambers All outlets and downpipes from the roof should have easily accessible chambers with removable covers to prevent materials being washed down, but also enables direct access for maintenance and inspection. Loading Weight It is fundamental that the saturated weight of the proposed green roof system is obtained and the information is given to a chartered structural engineer. All loading values are based on saturated loads

96 Every green roof is being designed and installed for a reason, those reasons usually corresponds to one of the recognised benefits of green roofs. The advantage of a green roof, is that whichever benefit is being prioritised, some aspect of the others are also achieved. From the list below decide what the reason is for your green roof (more information on each point can be found in the Benefits section), and keep that reason in mind as you design the roof. Reasons Water attenuation Increase roof lifespan Improve local air quality Cool building / Reduce Urban Heat Island Effect Design requirements Substrate depth of at least 80mm,* ideally deeper < 200mm. Reservoir / drainage board with water holding capacity. Unrestricted water escape. Substrate depth of at least 80mm.* Double skin exposed waterproofing. Substrate depth of at least 80mm,* ideally deeper < 200mm. High % of roof covered by vegetation. Varied types and heights of plants. Substrate depth of at least 80mm,* ideally deeper < 200mm. High % of roof covered by vegetation. Varied types and heights of plants. Conserve biodiversity Improve water quality Reduce sound transfer Amenity space Aesthetic impact Substrate depth of at least 80mm,* ideally deeper < 200mm. Varied depths of substrate, undulate between depths across the roof. Varied types and heights of plants. Include natural features. Substrate depth of at least 80mm,* ideally deeper < 200mm. Specific substrates and minerals can be used to filter out particular elements. Substrate depth of at least 80mm,* ideally deeper < 200mm. Substrate depth of at least 80mm,* ideally deeper < 200mm where planted. Protection mat. Drainage board. Good safe access and stable walkways. Edge protection of at least 1.2m height from top of substrate or walkways. Substrate depth of at least 80mm,* ideally deeper. High % of roof covered by vegetation. Varied types and heights of plants. May require irrigation. * In line with the GRO Code 2011:

97 Access Requirements Green roofs are typecast according to their depth and maintenance requirement. The following names for different green roofs have been adopted by the construction industry: Considerations dependent on the green roof being new-build or retrofit? Features of any Green Roof: Access required Minimum maintenance Regular maintenance Type of access Access can be via ManSafe cable system or cherry picker. Access can be via ManSafe cable system or cherry picker, however, total personnel enclosure is preferred by the Health & Safety Executive. A building structure designed to take the loads of the green roof Waterproof membrane and root resistant membrane Protective sheet Drainage system to allow excess water to leave the roof easily 500mm gravel or paving margin to all roof penetrations Up-stands of a suitable height to prevent material being blown off the roof A 1m wide, 300mm tall un-vegetated barrier every 40m Growing medium with no more than 20% organic matter Full public Partial roof access Visually overlooked access Total personnel enclosure must be provided i.e. a perimeter barrier of at least 1.2m from the top of the substrate, must be in place to all open sides. Ideally any barrier should be set inside the line of the edge of the roof. A viewing deck or enclosed patio is a good solution, however the perimeter must have barriers at least 1.2m from the top of the substrate or walkway. This type of site can be via ManSafe cable system or cherry picker. New-Build Specific Green Roof System - No matter what species of plants are specified, for them to flourish the green roof system needs: Sunlight Moisture Protective sheet Drainage Aeration to the plants root systems Nutrients To achieve this, a successful system must replicate nature, but within a compressed space. Most green roofs will have depths of between 80mm and 200mm, only roof gardens incorporating turf, shrubs and trees would be expected to have greater depths

98 A common green roof build up consists of: Roof resistant barrier Protection layer Drainage layer Filter layer Growing medium Vegetation Appropriate components i.e. outlet inspection chambers, 500mm vegetation barrier. Retrofit Specific Structural Capacity When retrofitting a green roof on to any building it is advisable to have a suitably qualified person undertake a structural survey of the building. Many older buildings were over designed/engineered and have spare capacity in their structure, which will allow green roofs to be fitted without additional construction. Conversely, many newer buildings and industrial units are built near to the limits of their capacity. The loading of the green roof must be established before the survey is carried out to ensure capacity. Once the building s general loading capacity is known and any strong or weak loading points identified, the green roof can be designed to suit, or the capacity of the building can be adapted. Deeper substrate depths can be placed where loading capacity is higher i.e. above supporting columns. Plant Level Substrate Filter Sheet Drainage Layer Protection Mat Root Barrier Water-proofing* Roof Construction Water Escape When a green roof is being designed, there will be an anticipated level of water retention within the layers and substrate. It is crucial to the success of the roof that any excess water is drained from the roof as quickly as possible. This will prevent ponding and over-loading. *If the water-proofing is not root-resistant, a root barrier should also be used

99 Construction Practice How should delivery and storage of materials be organised? How do different green roof systems affect construction? a) Mat-Based Green Roofs - Typically consist of pre-grown mats of sedum or meadow flowers placed over water retentive material (e.g. horticultural rock wool), or a thin layer of substrate. Pre-cultivated mats are a good solution for wind-exposed areas, as they hold additional substrate in place. Biodegradable nets can be secured to hold the mats in place. These materials simply require rolling out like turf, cutting to size and watering in. The rolled up vegetation mats will suffer if they are stored in rolls for more than 48 hours. Aim for these to arrive on site the day they are to be installed. b) Substrate-based Green Roofs - Layers of growing medium, which support plant growth. The materials come to site as separate elements; the moisture mat, drainage board and filter layer. The substrate will be delivered in bulk bags, craned on to the roof and spread or blown using hoses. c) Biodiverse / Wildlife Green Roofs - Locally sourced aggregates and natural features are used to recreate habitats for specific species or a variety of flora or fauna. Successful biodiverse and wildlife roofs need a high level of design input from specialists if they are to provide suitable habitats for the target species. Biodiverse roofs are normally left to vegetate through natural colonisation but may also be seeded with a local wildflower seed mixture or suitable wildflower plugs. All green roofs, which include intentional vegetation, should be watered-in for between 4 and 6 weeks after installation, depending on the weather at the time. a) Programming - Ideally the green roof should be the last element of constructions on any development. Elements of the roof which are living products i.e. plants, must be delivered in a just in time manner. b) Vegetation Care and Preparation - Ensure good water pressure is available at roof level. All plants and pre-grown mats should be well watered while in storage and after installation. Depending on weather conditions, 6 or 8 weeks of watering may be required. c) Site Storage - Where materials come on to site that need to be stored, care should be taken to reduce the risk of damage. Bulk bags of substrate should not be stacked more than two bags high and the substrate should not get mixed with other aggregates. d) Delivery to the Roof - Materials should be stored at ground level and carried, craned or pumped up when required. Ensure that materials are not stored, even for a short time, in a single area on the roof - although a building may be designed to take the additional load of a green roof, this is usually based on even distribution. Are there seasonal considerations when planning green roofs? a) Planting Seasons - Spring / Autumn are the best times to install a green roof and ensure successful establishment. It is recommended that green roofs are not installed during Summer - this needs to be factored into the construction programme. b) Exceptions - Biodiverse roofs, which are not intended to have plants on them from an early stage, can be installed at any time

100 Biodiversity & Planting What are the main types of green roof plant? a) Choosing Vegetation - Vegetation is what defines a green roof. It determines the visual character and quality of the roof. Its successful establishment is therefore central to a successful green roof. Whilst roofs covered purely in substrate or aggregate will have benefits, the plant layer will enhance and magnify those benefits. Vegetation protects the substrate from leaching and erosion; it traps, absorbs and evaporates rain water; contributes to cooling the roofs surface; provides food and habitat for invertebrates and birds; and will aid the capture of air pollutants and provide a sink for atmospheric carbon. The green roof environment is particularly harsh for plant growth: very shallow growing medium; limited water and nutrients; increased exposure to wind and intense sunlight. But it is not an impossible environment, and a large number of plants are well adapted to coping with drought stress or very shallow soils because the places that they grow naturally are very similar: rocky cliffs, dry grasslands, etc. Many green roof plants are low and spread, to effectively cover the surface. There are many other more specific conditions for plant choice that may be related to a specific function or type of roof: the aesthetics of the plant, whether it provides a food source for invertebrates, is it characteristic of a particular habitat or region, etc. Sedums are the most widely used plants for green roofs. They are supremely drought-resistant, and able to grow in shallow, freedraining substrates. Many grow naturally on bare rock surfaces. They were widely used in the early days of the development of extensive green roofs because they naturally colonised aggregate-covered flat roofs. However, sedums have come to have a rather negative association on ecological grounds. This is to some extent unfounded, and is more to do with the way they are used, rather than with the plants themselves. Sedum-only mats used in super-lightweight green roofs with little or no substrate can result in low-diversity roofs, with sparse or poor plant growth. However, when used in substrate-based systems, and when mixed with a wider diversity of plants, sedums can provide an essential fail-safe against summer drought, and provide an excellent nectar source during the flowering period. b) Succulents / Sedums - Succulent species store water in their leaves and have considerable moisture-conserving abilities. Green Roof Sedums are the most commonly used: mostly evergreens, with year-round plant cover, and a wide variety of leaf shapes and colours. Most species flower in May and June and the most common flower colours are yellow or pale pink. Reliable and widely used species include Sedum album, S.acre and S.rupestre (widely naturalised in the UK). These species all have relatively small leaves, as does S.hispanicum. S.spurium has larger, flatter leaves and provides a visual contrast to the other types in a mixture

101 c) Flowering Plants - Herbaceous species and alpines: Plants in this group give visual, structural and ecological diversity to a green roof. Widely used and reliable species include Tunic Plant, Petrorhagia saxifraga with pink flowers on dense, finely leaved plants, and Chives. Dianthus species such as D.deltoides and D.carthusianorum are effective, the latter seeding freely around a roof from year to year. d) Grasses - Grasses can form the sole component of green roof vegetation, but on their own can be prone to drought damage and die-back on un-irrigated green roofs. As part of mixed vegetation they provide visual contrast and structural diversity. Freely seeding grasses can dominate a roof and lower vegetation diversity. Koeleria glauca and K.macrantha are suitable, as are many Festuca species. e) Native Wildflowers - The increasing interest in green roofs for biodiversity has led to great interest in the use of native plant species. Dry grassland plant communities offer much potential

102 How can plants be established on a green roof? a) Pre-grown Vegetation Mats - Vegetation mats offer instant greening, to a known specification. A geotextile mat supports a thin layer of growing medium, into which the plants are established at the plant nursery before being transported to the site. The most common type are sedum mats, composed of a mix of different sedum species. These mats are often laid over minimal depths of substrate or directly onto a moisture retention mat, thereby creating very lightweight systems, and in some instances this may be the only option available. Good contact between the mat and whatever is underneath is essential during the establish phase, and irrigation may be necessary. Species-diverse vegetation mats are also available for green roofs, these may contain sedums, but also include a range of flowering plants. Such mats have greater aesthetic appeal and biodiversity value, but must be used with a substrate layer. Wildflower turf can contain a good range of appropriate native species. Turf should only be considered where irrigation is available and a reasonable depth of growing medium is being used. b) Plug planting - Plugs are small rooted cuttings or seedlings, grown in small compartments in cell trays containing compost. They are relatively cheap and allow a roof to be vegetated with a known mix of plants in the desired densities and arrangements. The plugs are planted directly into the substrate. Typical density of planting is plants per m². Planting in staggered rows ensures an even coverage. The plugs should not be allowed to dry out in the trays, and should be thoroughly moistened before planting (dry plugs will hinder or prevent root outgrowth into the surrounding green roof growing medium), and the roof kept moist until the plug plants begin to root out into the growing medium. Sedum species are also available in larger plugs or discs, which are established in exactly the same manner. In some instances, desired plants may not be available as plug plants, and container grown plants may have to be used. The smallest container size possible should be used (the mass of highly organic compost in most nursery obtained container plants can hinder new root growth out into the more harsh green roof growing medium. If container plants are to be used, the roots should be loosened prior to planting to enable the greatest contact of roots with the green roof growing medium. c) Cuttings - Sedum species root readily from fragments of leaves and stems. Bags of sedum cuttings are readily available, which are strewn across the surface of the leveled growing medium on the roof. It is essential that the cuttings remain moist until rooting has occurred. On a large scale, hydro-seeding techniques are used, whereby the cuttings are pumped out onto the roof in slurry of water-retentive gel and nutrients. The additional moisture holding capacity aids establishment

103 d) Seedings - An alternative approach that is particularly useful if the growing medium is very coarse and seeds are likely to fall or be washed deep into the substrate is to thinly spread a pre-inoculated (i.e. containing the required seed mix) layer of sand or fine growing medium over the surface. The seed will already be incorporated into the growing medium and the surface will only require a light firming. Seeding is best undertaken in the autumn or late winter/spring. Some species require winter chilling, and therefore spring sowing of the plants would not be effective. e) Natural Colonisation - The most cost-effective and ecological approach to vegetating green roofs is to allow natural colonisation: enabling plants which blow on to the roof surface naturally, or which are brought there by birds. It is a good vegetating technique for biodiverse roofs. Those plants that establish, survive and persist, will be well adapted to the green roof conditions and will also be reflective of the typical vegetation of disturbed sites in the immediate area. It is best used with infertile or freely draining substrate - rich and productive substrates can encourage a rank, low-diversity outcome. However, this method leaves very little control over the composition of the vegetation, and only certain types of plants are able to get to the roof. Many of the really tough and reliable green roof plants are not so mobile and would never get to the roof by these means. The aesthetic appearance can be very wild due to the lack of control, however, interesting and unexpected species can arrive, creating a unique roof. There is no need to be restricted to using one method only, plug plants can be used to create reliable and known vegetation, and a seed mix sown between. Sowing and planting of desired species onto biodiverse roofs can enhance natural colonisation. Which species are to be conserved on the green roof? Biodiverse or wildlife roofs are designed to either replicate the habitat for a particular species or create a range of habitats to encourage an array of species. Roofs that replace or replicate habitats are becoming more common in the UK. These roofs are referred to as: biodiverse; brown; rubble; brownfield; eco; habitat or even by the name of the species they are aimed at, i.e. Black Redstart roof. A wildlife roof is not necessarily the least expensive option, nor should it be considered as an opportunity to recycle unscreened site waste on the roof of a new development. British Building Regulations outlaw the direct transfer of demolition waste to roof level, without adequate screening for potentially polluting elements within the materials. Such materials may not be suitable to attract intended species. Substrates such as topsoil are very fertile and heavy when saturated and may have the seed or propagules of undesirable species within them, leading to a higher maintenance requirement. When designing a wildlife roof, consider: which species are to be conserved? As with any green roof, the growing medium is key to the success and should complement the essential elements to the survival of the species, e.g. invertebrates prefer less compacted substrates that can be burrowed into to escape the midday sun. Before deciding on which habitat to create or species to target, consult your Local Biodiversity Action Plan (LBAP) to highlight priority species and their favoured habitat in need of protection in your area. These are available online or from your local Wildlife Trust. LBAP s apply to habitats, plants, invertebrates and birds

104 44 What additional features should be included to promote a biodiverse green roof? a) Substrate for biodiverse and wildlife roofs - Not considered a growing medium. When specifying a biodiverse green roof a particular type of habitat is usually trying to be achieved. b) Mosaics of habitat - If the roof is large enough, it may be possible to create a variety of microhabitats to increase the sites attractiveness to plants, invertebrates and birds. You may want to section off the roof or have a different habitat on each roof space. Different habitats can be created with substrates, plants and depth. c) Vegetation - Many wildlife roof designers allow self-colonisation to occur on the roof, thereby allowing a more locally appropriate habitat to develop from the local seed bank. Pre-grown vegetation mats are normally unsuitable for wildlife roofs due to the small number of species they contain. It is also difficult for invertebrates to dig into the mats and make nests below the surface, with the exception of those grown specifically for the purpose. d) Natural features to attract wildlife Logs - Trees sawn into logs of no more than 600mm in length, laid on top of each other to provide nesting for insects and perches for birds. Stacked to no more than 350mm high. Clean / Cleaned Bricks - Dumped in a pile to provide habitat for spiders and insects. Stacked to no more than 350mm high. Stones - Local stone, cobbles or rocks can be used to create mounds for insects to live in and birds to peck through. Stones should be no more than the size of a fist or in the case of flat stone about the size of a plate. They must be stacked no more than 350mm high. Sand - Ordinary sharp sand or builders ballast can be used to create either sand beds or sand mounds for species of insect and especially bees which nest in sand. Mounds should not be higher than the top of the nearest upstand. Note: Demolition waste and site won materials can not be put straight on to the roof without screening for possible contaminates, harmful materials and there may also be seed banks of undesirable plants within any fine material

105 46 Maintenance How should maintenance be managed? a) Maintenance - Perceived to be one of the greatest barriers to their installation. The maintenance schedule should be considered during the design process, when the demand for maintenance input can be anticipated. There is no such thing as a no maintenance roof. it is strongly advised to include the cost of the post installation maintenance programme within the budget and tender documents. Biodiverse and low-maintenance roofs will still require visits once or twice a year to clear gutters and drains. Roofs near to deciduous trees also need maintaining in late autumn to clear leaves. b) Extensive <100mm Low Nutrition Substrate - Drainage outlets and inspection chambers cleared of vegetation, as with any roof. Ensure outlets and shingle perimeters are clear of plants. c) Semi Extensive - 100mm to 200mm low to medium nutrition substrate - Drainage outlets and inspection chambers cleared of vegetation. Ensure outlets and shingle perimeters are clear of plants. Removal of undesirable vegetation 6 monthly. d) Intensive - 200mm+ medium nutrition substrates and top soils - Drainage outlets and inspection chambers cleared of vegetation. Ensure outlets and shingle perimeters are clear of plants. Take care of lawns, hedges, etc. Replacement of failed plants exceeding 5% of plants installed. Replenishment of any areas of settled substrate. e) Biodiverse - Very low, to low nutrition - Drainage outlets and inspection chambers cleared of vegetation. Ensure outlets and shingle perimeters are clear of dead and live plants. Low vegetation is common and none is general undesirable. f) Post Installation - Many contractors will include, or at least suggest, an agreed period of regular maintenance. This is especially important whilst the roof is establishing. Some extensive green roof system suppliers will have their own approved contractors who will monitor progress immediately following installation and after the first full growing season (usually between months) before finally signing over maintenance duties to the building manager. increasing numbers of contractors have received specialist training in green roof care from organisations such as GRO and BALI. What are the key factors that should be considered during maintenance? a) Undesirable Plants - All efforts should be made to prevent drains becoming blocked and the growth of unintentional vegetation which could be detrimental to the intentional planting regime, biodiversity aims and the building fabric (Buddleia, for example, should be removed while still immature). b) Irrigation - Access to a water point is essential during the establishment stage of most green roofs. However, on an extensive green roof, a permanent irrigation system is not necessary. This may be required on intensive roofs in rain-shadowed locations. The deeper the substrate, the more moisture it can hold to ensure plant survival during dry periods

106 48 c) Fertilisers - The preferred option is not to fertilise extensive green roofs, as species diversity may be reduced and the use of fertiliser will result in increased nutrient levels in storm-water runoff, which will negatively affect local water quality. Where fertiliser is required to maintain the health of particular plant species, fertiliser application should be kept to a minimum and should be in accordance with the advice of the supplier. Where rainwater is harvested from a green roof, fertiliser should not be applied. d) Fire Breaks - Vegetation breaks/barriers have an important safety function and prevent the spread of fire. All vegetation barriers at upstands, roof penetrations and firebreaks must be maintained at their original width and cleared of any encroaching plants. e) Drain Heads and Outlets - All drainage points must be checked every year and cleared out if necessary to ensure optimum performance. Excess water must be able to leave the roof, to avoid ponding and overloading. f) Health and Safety During Maintenance - Where maintenance will be undertaken within 2m of the edge of a green roof, fall protection must be provided. It is important that fall protection systems are themselves maintained once a year. There are examples of green roofs on low-rise buildings that are now being designed so that the complete roof can be accessed from a cherry picker to reduce the risk of accidents. How can damage be minimised during maintenance? a) Build-Up Awareness - Ensure anyone working on the roof is briefed as to the build-up of layered components. b) Tools - Tools must be carefully chosen so as not to interfere or damage anything below the substrate. c) Programme - Works should be programmed in order to minimise the amount of traffic across the green roof after installation. Repeated walking on a limited area of green roof will result in substrate compression and damage to vegetation

107 50 Glossary of green roof terms Biodiverse Roof Wildlife or brown roof designed to either replicate the habitat for a single or limited number of species or to create a range of habitats to maximise the array of species, which inhabit the roof. Brown Roof Biodiverse or wildlife roof designed to either replicate the habitat for a single or limited number of species or to create a range of habitats to maximise the array of species, which inhabit the roof. BS British Standards formulated by the British Standard Institute (BSi). Drainage Layer / Reservoir Board Part of the standard green roof build-up, which allows excess water to drain away to the down pipe outlets. Some drainage layers also provide a reservoir effect to retain moisture for a longer period to help maintain. Drainage layers may be made of a variety of materials including hard plastic, foam or coarse gravel. DIN Standards Deutsches Institut für Normung German Institute for Standardization. DIN Standards are the published results of DIN s work. Extensive Green Roof Low nutrient and low maintenance, also often designed to be lightweight. Not irrigated. Usually shallow substrate, typically less than 100mm, and often vegetated with sedum. Filter Fleece / Fines Layer Part of a standard green roof build-up, which prevents fines and sediments from being washed into the drainage system. FLL Forschüngsgesellschaft Landschaftsentwicklung Landschaftbau (Landscape Research, Development and Construction Society) Green Roof A roof or deck onto which vegetation is intentionally grown or habitats for wildlife are established, including: extensive, intensive and semiintensive roofs; roof gardens; biodiverse roofs; brown roofs; public and private amenity spaces. The Green Roof System The layers of material, which make up a green roof build-up. Growing Medium / Substrate An engineered soil replacement specifically designed to give green roof plants what they need to survive and to allow water to be absorbed and drain away. Substrates contain specified ratio of organic and inorganic material. GRO Green Roof Organisation: The industry forum for green roof development and promotion in the UK, facilitated by the NFRC. HSE Health & Safety Executive

108 52 Hydro Seeding Spraying a specially designed blend of seeds and growing medium. Intensive Green Roof A green roof that requires intensive maintenance. Usually irrigated and usually with more than 200mm depth of substrate. Equivalent to a garden and usually referred to as a roof garden. Protection Layer Relatively thick (2mm) geotextile blanket, which provides protection to the waterproof membrane while the other parts of the green roof system, are being installed. Reservoir Board / Drainage Layer Part of the standard green roof build-up, which allows excess water to drain away to the down pipe outlets. Some drainage layers also provide a reservoir effect to retain moisture for a longer period to help maintain. Drainage layers may be made of a variety of materials including hard plastic, foam or coarse gravel. Root Barrier A membrane or layer designed to prevent roots from penetrating the waterproofing layer and building fabric. Sedum A genus of about 400 species of low growing leafy succulents, which are drought tolerant and found throughout the northern hemisphere. Not all species are suitable for roofs. Semi-intensive Green Roof Intermediate green roof type with characteristics of both extensive and intensive green roofs. Typically 100mm to 200mm substrate depth, sometimes irrigated, occasionally managed, and usually planted with a range of species. Standard / Traditional / Conventional Roof Un-vegetated and non-absorbent roofs i.e. asphalt, single ply, mineral felt, liquid applied, metal deck etc. Substrate / Growing Medium An engineered soil replacement specifically designed to give green roof plants what they need and to survive and to allow water to be absorbed and to drain away. Substrates contain specified ratio of organic and inorganic material. System The term given to the combination of layers in a green roof build-up. SUDS Sustainable (Urban) Drainage Systems. Vapour Barrier Typically a plastic or foil sheet that resists diffusion of moisture through wall, ceiling and floor in a buildings. Wildlife Roof Biodiverse or brown roofs designed to either replicate the habitat for a single or limited number of species or to create a range of habitats to maximise the array of species

109 54 This guide has been developed in partnership with national and European experts including The Green Roof Centre at the University of Sheffield, Livingroofs.org, GRO (Green Roof Organisation), the Environment Agency and Homes & Communities Agency. Funded by: Life+ Fund, European Commission Groundwork Sheffield Homes and Community Agency Green Roof Centre Livingroofs.org This guide is available online at: 109

110 110

111 Appendix J DIY Guide to green roofs 111

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117 Appendix K Case studies 123

118 Angram Bank Angram Bank Children s Centre, High Green, Sheffield Angram Bank Children s Centre is part of the government s Sure Start initiative to give support to families with children under the age of five. The children s centre has been built on the grounds of Angram Bank Primary School and provides a day nursery and adult learning facility. The new building has been constructed into a steep bank and carefully planned to maximise sunlight and incorporate sustainable features such as the lawn, wildflower and sedum roof. Contractors Kier Sheffield were awarded a commendation in the SCALA Design & Quality of Construction Awards in 2009 for the project. The enclosed embankment into which the children s centre is built opens up at the top into a flat lawned roof top play area. The grassed area is enhanced by the presence of wildflower borders and sedum areas to encourage biodiversity. As well as reducing the environmental impacts of the new building and increasing its life expectancy, the green roof provides a useful outside space in which to educate children. The building itself aims to incorporate sustainable low maintenance material and the green roof, embankment sides and beco block insulated concrete retaining walls contribute to high levels of insulation. Roof Type: Intensive Lawn / Extensive Wildflower and Sedum Roof Size: 300m² Main Contractor: Kier Sheffield Architect: Sheffield Design and Planning Managment Completed: 2009 With the contribution of the LIFE financial instrument of the European Community

119 Holt House Holt House Children s Centre, Sheffield Holt House Children s Centre is housed in a purpose built addition to the existing school premises. The project was undertaken as part of Sheffield Early Years Education and Childcare Service s aim to develop 31 fully operational children s centres across the city. The architects Sheffield Design and Planning Management worked alongside local contractors Malden Roofing. Malden installed a Bauder felt roof laid on metal decking with a VB4 Expal vapour barrier, G4E Underlay and Plant E-root resistant top layer. The substrate was Bauder extensive substrate. Early problems during construction resulted in the green roof being laid and seeded twice, as the first attempt had to be removed and re-laid. The slightly sloping roof is not accessible to the public, but can be viewed from ground level. Roof Type: Extensive Alpine / Wildflower seeded Roof Size: 100m² Main Contractor: Malden Roofing Architect: Sheffield Design and Planning Management Completed: October 2008 With the contribution of the LIFE financial instrument of the European Community

120 Humanities Research Institution University of Sheffield, Humanities Research Institution, Douglas Knoop Centre The imaginatively designed Humanities conference and seminar facility combines the old and the new; restoring the original Georgian architecture and creating a new flexible conference space, recessed into the ground so that the two buildings sit comfortably side by side. The new Douglas Knoop centre has a flat lawned roof which is designed to soften the presence of the contemporary structure and compliment the delicate neatness of the existing Georgian architecture. The intensive lawned roof has a substrate depth of approximately 450mm which is built on to a concrete roof. The aesthetics of the green roof are driven by function with passive ventilation units radiating the area and a central circular glazed roof light present to allow light into the space below. Seating areas are placed adjacent to ventilation units providing a social use for the garden. The development has created an aesthetically pleasing, functional green roof which improved the functionality of the building below while creating an attractive recreational space for the buildings users. The Humanities building needed to expand on a limited space meaning that an innovative recessed design could accommodate the new conference room, digital suite and seminar room without creating a cumbersome extension. The roof was a key feature in the design, creating a usable garden space for social use and an environmentally efficient roof construction. Roof Type: Intensive Lawn / Roof Garden Roof Size: 450m² Roof System: Erisco Bauder Main Contractor: William Birch and Sons Roof Contactor: Malden Roofing Architect: Bond Bryan Architects Completed: May 2006 With the contribution of the LIFE financial instrument of the European Community

121 Manor Lodge Sheffield Manor Lodge Discovery Centre Sheffield Manor Lodge Discovery Centre is a purpose built education and visitors centre which was funded by the Heritage Lottery Fund ( 1.25million). It is the gate way to the Sheffield Manor Lodge site and is used for exhibitions and displays allowing visitors to learn about the relatively unknown Scheduled Ancient Monument site. Green Estate Ltd is a social enterprise which manages the site. The Discovery Centre features a green roof with a graduated substrate depth, reaching 200mm at the centre and sloping down to 100mm at the building s edge on the soft pitch of the roof. The Substrate has been seeded with a grass seed mix composed by Green Estate. For increased aesthetic appeal, the roof also contains plug plants which flower over the summer months. The roof is a showcase of what Green Estate can do. The Manor Lodge site also hosts other green roofed developments including arts and crafts studios with 400m² of grass seeded roof, a horse shelter with Lindum blanketed roof and a small storage shed. The intention of the developments at Sheffield Manor Lodge are to create a valued space which is transformed and managed in a way that demonstrates environmental excellence, protects the site and enhances the local heritage while delivering social fairness for current and future generations. Roof Type: Grass Seed Mix / Plug planted Roof Size: 350m² Substrate Depth: mm graduated Roof Contractor: Green Estate Ltd Completed: 2009 With the contribution of the LIFE financial instrument of the European Community

122 Regent s Place Regent s Place is a development of three new multi-storey buildings in London, comprising of office and residential space. Arup Environmental designed the roof at Regent s Place, working closely with client British Land to help implement their corporate Bio-diversity Action Plan. Arup were tasked with designing green roofs to cover two terraced areas and one roof, all sited in prominent locations and therefore needing to be aesthetically pleasing at different times of the year. Once the waterproof membrane was in place, a puzzle pattern was created, using polyester powder coated vertical aluminium dividers laid over a reservoir board to compartmentalise the roof and terraces. Each compartment was then filled with one type of growing medium, installed at different depths to create different habitats. Substrates used included: pebbles, crushed brick, limestone chippings, pine bark strippings and pellite. Planting varied between compartments, and included mosses, sedums, wildflowers, grasses, small shrubs and aquatic plants, according to the type of substrate and orientation of the compartment. The finished project combines aesthetics with benefits to local bio-diversity, providing essential habitat for a range of invertebrate species, and foraging habitat for birds including the Black Redstart. Roof Type: Bio-diverse Roof Size: 2,600m² Roof Contractor: Tilbury Contracts Ltd (using ZinCo Green Roof and Hydrotech MM6125 from Alumasc) Architect: Terry Farrell Ltd Bio-diverse Roof Architect: Arup Environmental Completed: September 2009 With the contribution of the LIFE financial instrument of the European Community

123 Rockliffe Hall Rockliffe Hall Hotel Rockliffe Hall in Hutworth, near Darlington, is a listed building set within 375 acres of preserved countryside. The 19th century estate s recent extension houses a luxury hotel, spa and the UK s longest golf course. The location for the Hall s new clubhouse was carefully selected so that it sat low down in the surrounding landscape. The architects worked closely with Alumasc s Technical Support Team to create a green roof that blended seamlessly into its location, making the clubhouse almost invisible from the hotel. Wild grass varieties were selected to harmonise with surrounding plant species, and to complement the clubhouse s natural timber facade. Roof Type: Extensive Roof Size: 1,600m² Roof Contractor: Roofclad Systems (using Alumasc ZinCo Extensive Green Roof) Main Contractor: Shepherd Construction Ltd Architect: Browne Smith Baker Completed: January 2009 With the contribution of the LIFE financial instrument of the European Community

124 The Cube The Cube is a mixed use apartment and business development situated in Sheffield s cultural industries quarter. The development, created through a partnership of and Derwent Living, boasts an innovative example of 21st Century sustainability incorporating a green roof. The green roof system was installed over a 661m² area. The substrate used comprises of 70% crushed brick and 30% organic matter spread unevenly across the roof space with an average depth of 80mm. The roof is a wildflower meadow, chosen to enhance biodiversity in the city centre. A short flowering seed mix of drought tolerant grasses, alpines and perennials specially formulated by Dr Dunnett of Sheffield University via Pictorial Meadows and Green Estate. Unlike using sedum blankets, the seeding method does not provide an immediate greening effect but takes time to establish. Within the first year, about 60% coverage was achieved. However, once established, seeds are lower maintenance and result in more interesting habitats which are better suited to Sheffield s climate. Aims of the Green Roof: To provide an environmentally friendly solution for the roof of The Cube, To provide a site to monitor the pictorial meadows seed mix so it may assist in the future development of green roofs in the Sheffield area, To provide a demonstration site in the heart of the city centre to show other developers and contractors the benefits of green roofs creating a sustainable blueprint for them to copy. Roof Type: Biodiverse Semi-Extensive Wildflower seeded Roof Size: 661m² Main Contractor: Harrisons Roof Contractor: Green Estate Ltd and Paragon Roofing Architect: Carey Jones Completed: March 2007 With the contribution of the LIFE financial instrument of the European Community

125 Peacehaven Peacehaven Wastewater Treatment Works The 300million Peacehaven Wastewater Treatment Works in East Sussex features the UK s largest curved green roof. The 17,800m² roof was a key factor in securing planning permission for the site after a decade of delays. The building was sunk into the ground to minimise its visual impact and the roof s curved profile helps to integrate the plant into the surrounding landscape of rolling downs. Southern Water proposed the new Works in order to treat 95 million litres of wastewater a day generated from various sites. Work began in July 2009 and the roof was completed in May The plant will be fully operational by spring The green roof, which was supplied by Frost Landscapes Ltd, enhances the scheme s sustainability and biodiversity, while helping to attenuate rainwater run-off and provide excellent thermal insulation. The Derbigum Rapido waterproofing system, a vital element of the green roof and one of the main contributors to the success of the project, was developed by Alumasc and the installing contractor, Prater Ltd, to meet the requirements of the client, Southern Water, and architect Montgomery Watson Harza. Following their work on the project, Prater have been awarded the sought after Costain Blue Standard for contractors and have been shortlisted for the Contractor of the Year awards. Prater won the green roof category in the 2012 NFRC Roofing Awards. Roof Type: Extensive Roof Size: 17,800m2 Roof Contractor: Alumasc & Frost Landscapes Ltd Main Contractor: Prater Architect: Montgomery Watson Harza Completed: May 2011 With the contribution of the LIFE financial instrument of the European Community

126 West Ham Bus Garage The 48million West Ham bus garage is the largest in the capital and was commissioned to meet the increased demand for public transport during the London 2012 Olympic Games. The West Ham site houses over 300 buses and is the largest and greenest bus garage in the UK. It includes a range of environmental features and produces more than 20% of its own energy needs from renewable on-site sources. Pringle Richards Sharratt Architects (PRS) commissioned approximately 4,000m² of Blackdown s Extensive Nature Mat green roof system, which covers half of the overall roof area. The roof has helped to improve the biodiversity of the local area and forms an important part of the site s sustainable urban drainage system (SUDS). The Weat Ham bus garage has been awarded an A rated Energy Performance Certificate, and is predicted to produce 27% less CO² emissions than an equivalent building built with traditional materials. Blackdown and roofing contractor Lakesmere jointly won the Best Sustainable Green Roof award at the 2011 NFRC Roofing Awards. Roof Type: Extensive Roof Size: 8,000m² in total, 4,000m² of which is green Roof Contractor: Blackdown Greenroofs & Lakesmere Main Contractor: Mansell Construction Services Architect: Pringle Richards Sharratt Architects Completed: 2008 With the contribution of the LIFE financial instrument of the European Community

127 Appendix L Life consultation press release 127

128 Appendix M Opinions sought as UK Green roof guide nears completion Consultation begins on green roof code of best practice Groundwork Sheffield are seeking opinions on the UK s first ever online guide for designing and constructing green roofs In relation to planning and biodiversity guidance. The free guide, funded through 320,000 of European Life+ funding aims to raise the standard of green roof design and installation across the UK by providing best practice guidance for the construction industry. Comments are welcomed from building professionals, architects, engineers, ecologists and anyone else with an interest in green buildings and sustainability. Green roofs perform a vital role in mitigating the effects of climate change by reducing the need for artificial cooling in hot weather and capturing rainwater run-off, as well as providing a range of habitats for urban wildlife. But green roofs can only deliver on these environmental benefits if installed to the highest specifications. The guide is of critical importance as every green roof is bespoke and must meet minimum specifications if maximum benefits are to be experienced. Consultation has occurred with European experts and key stakeholders in the green roof arena including The Green Roof Centre, Livingroofs. org, the Environment Agency and Green Roof Organisation (GRO). Anyone wanting to contribute views should visit The deadline for comments is May 2011 For further information contact: Anna Cooper on

129 Appendix M Project launch press release 129

130 Appendix N January 2009 New lease of LIFE for Green Roofs Groundwork Sheffield gets go-ahead for 914,213 project Groundwork Sheffield has successfully secured European Life+ funding to raise the standard of green roof design and installation across the UK. Green roofs perform a vital role in mitigating the effects of climate change by reducing the need for artificial cooling in hot weather and capturing rainwater run-off, as well as providing a range of habitats for urban wildlife. But green roofs can only deliver on these environmental benefits if installed to the highest specifications. Currently there are no UK-specific standards, which mean there is an over-reliance on European standards which have not been developed for the UK climate. The Life+ funding contributes to a Euros 914,213 project that will enable Groundwork Sheffield, in partnership with national and European experts, to establish a UK code of best practice for the design and installation of green roofs. Project partners include The Green Roof Centre, Livingroofs. org, Clear Ltd and the European Federation of Green Buildings. LIFE+ is the EU s financial instrument supporting environmental policy development across Member States. For more information on the project please contact Wendy Bussey, Groundwork Sheffield on

131 Appendix N Judging pannel for NFRC

132 Appendix O Judging Panel for National Roofing Awards 2010 Judging the Excellence in Roofing Awards Special thanks to our judges: Julyan Gordon, Master of the Worshipful Company of Tylers & Bricklayers; Damon Schunmann, Features Editor of Construction News; Dr. Paul Blackmore, Associate Director of BRE, Alan Williamson, Director of Michael Kilbey Associates and Bob Hann, FRA Honorary Life Member. Also thanks to our independent adjudicator Nicky Rogers, Editor of Roofing Magazine and our technical experts: Kevin Taylor (NFRC), Ian Henning (NFRC), Paul Stephenson (SPRA), Bill Jenkins (FRA), Wendy Bussey (The Green Roof Centre) and Carl Bream (LCA). 132

133 Appendix O Local authorities consulted 133

134 First Name Last Name Job Description Council Andrew Christina Martin Mark Julia Tom Jenny Peter Rosemary Ian John James Matthew Chris David Becki Hazel Jon Steve Fiona Louise Helen Kate Sarah Tamara John Kristina Michael Chris Annie Karen George Adam Chris James Jeff Paul Kay Simone Bill Peter Colin Helen David Gary Alex Andrew Mike Miles Richard Colm Kathy Liz Pat Peter George Neville Chryse Debbie Bannister Doar Winnard Armitage Scott Lindsay Eckford Fallon Coyne Thomson Eyles Farrell Thomas Logue Hodcroft Tighe Honeysett Sutcliffe Molloy Edwards Briggs Blenkham Bell Greenborough Walters Oxley Peat Slater Thomas Cooper Perkins Munson Harvett Tinker Adams Prior Julings Butler Gorton Cooper Brindley Jeynes Brookes-Martin Renwick Kennison Nickson Jones Waite Duckworth Blakeway McCann Cartwright Curley Ashton Jepson Munson Stork Tinsley Hill Council Champion Biodiversity co-ordinator Development Control Manager Landscape Planner Head of Planning Chair Ecologist Sustainability Officer Directorate of Development Environmental Strategy Environmental Protection Sustainable City Coordinator Housing Stratergy and Enabling Manager Council Champion Landcsape Planning Officer Helped Refurbish Sheffield Cathedral Green Roof Expert Climate Change Adaptation Strategy M Strategy Manager Policy Officer Advisor on Environmental Issues Environment Unit Environment Officer (Partnerships) Senior Development Officer Environment Directorate Climate change officer Head of Environmental Sustainability Landscape Planner Climate Change Officer Barnsley Metropolitan Borough Council Barnsley Metropolitan Borough Council Barnsley Metropolitan Borough Council Barnsley Metropolitan Borough Council Barnsley Metropolitan Borough Council Bedfordshire County Council Bedfordshire County Council Bedfordshire County Council Birmingham City Council Birmingham City Council Birmingham City Council Birmingham City Council Blaby District Council Blaby District Council Blyth Valley Borough Council Bradford Metropolitan District Council Bradford Metropolitan District Council Brighton and Hove Council Brighton and Hove Council Brighton and Hove Council Bristol City Council Bury Metropolitan Borough Council Bury Metropolitan Borough Council Calderdale Metropolitan Borugh Council Calderdale Metropolitan Borugh Council Cheshire County Council Cheshire County Council Cheshire County Council Cheshire County Council Chester City Council Chester City Council Chesterfield Borough Council City of Lincoln Council City of Lincoln Council City of Lincoln Council City of Lincoln Council City of York Council City of York Council City of York Council City of York Council Coventry City Council Coventry City Council Derbyshire County Council Derbyshire County Council Derbyshire County Council Doncaster Metropolitan Borough Council Doncaster Metropolitan Borough Council Doncaster Metropolitan Borough Council Doncaster Metropolitan Borough Council Doncaster Metropolitan Borough Council Doncaster Metropolitan Borough Council Doncaster Metropolitan Borough Council Doncaster Metropolitan Borough Council Doncaster Metropolitan Borough Council Doncaster Metropolitan Borough Council Doncaster Metropolitan Borough Council Dorset Council Dudley Metropolitan Borough Council East Riding of Yorkshire Council East Riding of Yorkshire Council Gateshead Council Gloucestershire County Council Greater London Authority Greater London Authority Greater London Authority Greater London Authority Greater London Authority High Peak Borough Council Kirklees Council Kirklees Council Kirklees Council Kirklees Council Kirklees Council Lancashire County Council Lancashire County Council Leeds City Council Leeds City Council Leicester City Council Leicester City Council Leicester City Council 134

135 Rebecca Sue Alan Christopher Steve Linda Phillipa Rachel Lawrence Chit Moy Leanne Richard Ian Pauline Stuart Ben James Lydia Peter Graeme James Adrian Stephen Eddie Tim Andrew Graham John Phil Rob Neil Philip Keith Eirwen Charles Cotton Timms Gledhill Bibb Golightly Beard Salter Hogger Pinturault Chong Cash Brisland Harris Blackley Manning Bayley Rose Brass Morrison McMillan Wilson Thompson McLoughlin Peel Rychlak Allen Ashall Megson Edwards Larter Smart Hunt Keynes Bennell Hopwood Clay Contract Landscape Architect Nature Conservation Officer Parks Superintendant Environmental Sustainability Officer Climate Change Officer Regeneration Project Manager Housing Sustainability Officer Biodiversity Officer Contaminated Land & Water Noise Pollution Midlothian Biodiversity Projects Officer Environmental Policy Conservation Officer Environment Officer (Built Conservation) Environment Team Manager Regional Planning Officer Head of Countryside Services Contract Administrator Sustainability Leicester City Council Leicester City Council Leicester City Council Lewes District Council Lewes District Council Lincolnshire County Council London Borough of B & D London Borough of B & D London Borough of B & D London Borough of Bexley London Borough of Camden London Borough of Camden London Borough of Islington Council London Borough of Sutton Luton Borough Council Luton Borough Council Manchester City Council Manchester City Council Manchester City Council Manchester City Council Manchester City Council Manchester City Council Midlothian Council Midlothian Council Newcastle City Council Newcastle City Council Newcastle City Council North Cornwall District Council North Devon District Council North Dorset District Council North Down Borough Council North East Derbyshire District Council North East Lincolnshire Council North East Lincolnshire Council North Hertfordshire District Council North Kesteven District Council North Lincolnshire Council North Lincolnshire Council North Lincolnshire Council North Norfolk District Council North Shropshire District Council North Somerset Council North Warwickshire Borough Council North West Leicestershire District Council North West Regional Assembly North Wiltshire District Council North Yorkshire County Council North Yorkshire County Council North Yorkshire County Council Norwich City Council Nottinghamshire County Council Nottinghamshire County Council Nottinghamshire County Council Nottinghamshire County Council Nottinghamshire County Council Nottinghamshire County Council Nottinghamshire County Council Nuneaton and Bedworth Borough Council Oadby and Wigston District Council Oldham Metropolitan Borough Council Oldham Metropolitan Borough Council Oldham Metropolitan Borough Council Omagh County Town Council Orkney Islands Council Oswestry Borough Council Oxfordshire County Council Oxfordshire County Council Pembrokeshire Council Pendle Borough Council Penwith District Council Perth and Kinross Council Peterborough City Council Peterborough City Council Plymouth City Council Portsmouth City Council Preston City Council Purbeck District Council Redcar and Cleveland Council Redditch Borough Council Renfrewshire Council Restormel Borough Council Rhondda-Cynon-Taff Council 135

136 Rachel Graham Richard Alan Ashley Rasuli Beverley Bruce Carolyn David David Hannah James Jason Karen Leon Malcolm Michela Paul Richard Sandra Stephen Stephen Steve Malcolm Steve Malcolm Howard Andrew Mike Philip Rachel June Matthew Philip Wayne Jeanette Stuart Terry Alf Amanda Andy Ann Bernard Bernard Bryan Cath Cath Chris Chris Cath Dan David David David Derek Emma Evelyn Miranda Fran Gary Gary Gary Geoff Gill Harry Helen Howard Ford Burgess Hughbridge Bamforth Langrick Azim Aldeton Carter Barber Potts Rhodes Richardson Cox Mckoy Gallagher Gasiorski Brown Griffith Smith Malkin Siner Lister Moralee Fryer Meekins Brown Browne Buckley Burton Gibbons Gill Overfield Rothwell Woodward James Priestly Burton Martin Hessleton Meade Stokes Nolan Gosse Little Hoermann Lodge Basilio Roff Heeley Roberts Arnold Lewis Anson Cooper Shepherd Statham Wells Milne Plowden Hill Weatherall Hunt McGrogan Aitken Furniss Harpham Wright Baxter Head of Regeneration Policy Planner Air Action Officer Building Control Surveyor Project Officer Policy and Partnerships Support Officer Planning Officer (Landscape) Sales Rep for South Yorkshire Architectural Manager Architect Head of Agriculture / Champion Senior Landscape Architect Engineer Transport Planner Researcher Environmental Strategy Landscape Officer Urban Designer Principal Planner (LDF Team) Heritage Parks Officer Head of Environmental Strategy Environmental Strategy Officer Architect Director for the East ADF Architect Councillor Neighbourhoods Directorate Social Services Property Manager North Sheffield Regeneration Team AM Richmondshire District Council Richmondshire District Council Rochdale Metropolitan Borough Council Rochford District Council Rossendale Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Rotherham Metropolitan Borough Council Runnymede Borough Council Rushcliffe Borough Council Rushmoor Borough Council Rutland County Council Ryedale District Council Salford City Council Salford City Council Sandwell Metropolitan Borough Council Scarborough Borough Council Sedgemoor District Council Sedgemoor District Council Sedgemoor District Council Sefton Metropolitan Borough Council Selby District Council Sevenoaks District Council 136

137 Ian Ian Ian Ibrar Jackie James Jan Sue Steve Jan Janet Jill Jillian Jillian Jim John John John John John John John Jon Joe Mary Julie Karen Kate Ken Keith Les John Lucia Lucy Mark Martin Mary Mary Matthew Mick Maire (Moya) Noel Penny Pat Paul Paul Peter Peter Robert Sam Sam Scott Shaffaq Shanza Simon Stella Stewart Stuart Stuart Sylvia Tim Vicky Viveen Caroline Aimee Silvia Colin Rick Mike Sally Egan Gill Janet Idris Paul Robert Richard Laurie Caroline Robert Johanna Debbie Ashmore Mitchell Taylor Hussain Drayton Barnes Fizgerald Barker Carvell Wilson Gaynor Ray Creasy Missen Breakey Batley Bownes Cotton Gaunt Keyworth Mothersole Webster Dallow Taylor Bagley Watson Wood Mansell Dunn Missen Sturch Crossley Holland Lorente-Arnau Setchell Peat Green Bagley Lea Ridge Crofts McCarthy Smith Thompson Midgley Bangert Scriven Price Slater Thompson Sykes Thorne Porter Mohammed Hussain Ogden Mekonnen Garvey Massey Turner Dunkley Rippon Penn Dennis Creswell Ambrose Anginotti Barnes Bingham Brearley Cuckney Diarmund Furniss Gaynor Hepworth Hudson Kerslake King Lane Leary MacDonald Mawson Merrill Design and Project Management Director for the South ADF Architectural technologist Landscaper Town Planner Architects Practice Manager Head of Environmental Services Executive Director Woodland Project Officer Councillor Landscape Architect Planning Officer Team Leader Environmental Planning Director of Development Services Development Officer Head of Service Councillor Director Premises & Assets - City Centre Manager Social Services specification manager Ranger Services Manager Urban Design Conservation Team East Sheffield Regeneration Team M Local Development Control Officer Housing Market Renewal Developer South Sheffield Regeneration Team M Development Manager Senior Architect Planning Chief Quantity Surveyor Head of Special Projects Chief Executive Councillor Regeneration Coordinator Planning 137

138 Roger Martin Slow Joanne Ian Caroline Andy Marilyn Philip Philip William Mike Andrew Angie Darren Emma Matthew Jerry Andrew Brian Ian Erica Tony John Nowell Page Rob Roney Stanwon Stiff Wild Hallard Heath Leves Blyth Winks Christelow Jukes Pegram Wilson Westbrook Smith Horrocks Rooney Stephenson Drew Phillips Harrison Conservation Officer Conservation Officer Training Mngr Principal Planning Officer Sustainability Officer Health & Environment Advisor Sustainability Team / Local Agenda 21 Nature Wildlife & the Unitary Development Environment Coordinator Community Planning Officer Corporate Director (Environment) Senior Project Manager Planning control manager Planning support manager Shrewsbury and Atcham Borough Council Shropshire County Council Solihull Metropolitan Borough Council Somerset County Council South Ayrshire Council South Bedfordshire District Council South Bucks District Council South Derbyshire District Council South Derbyshire District Council South Derbyshire District Council South Derbyshire District Council South Gloucestershire District Council South Hams District Council South Holland District Council South Kesteven District Council South Lanarkshire Council South Norfolk District Council South Northamptonshire Council South Oxfordshire District Council South Ribble Borough Council South Shropshire District Council South Staffordshire District Council South Tyneside Council South Tyneside Council Southampton City Council St Albans District Council St Edmundsbury Borough Council St Helens Metropolitan Borough Council Stafford Borough Council Staffordshire County Council Staffordshire County Council Stevenage Borough Council Stirling Council Stockport Metropolitan Borough Council Stockport Metropolitan Borough Council Stockport Metropolitan Borough Council Stockport Metropolitan Borough Council Stockton-on-Tees Borough Council Trafford Metropolitan Borough Council Tynedale Distrcit Council Uttlesford District Council Vale of Glamorgan Council Vale of White Horse Distrcit Council Vale Royal Borough Council Wakefield Metropolitan District Council Wakefield Metropolitan District Council Wakefield Metropolitan District Council Wakefield Metropolitan District Council Walsall Metropolitan Borough Council Walthomstow Parks and Gardens Wansbeck District Council Warrington Borough Council Warwickshire County Council Watford Borough Council Waveney District Council Wear Valley District Council Wellingborough Borough Council Wells City Council Welwyn Hatfield District Council West Berkshire Council West Devon Borough Council West Dunbartonshire Council West Lancashire District Council West Lancashire District Council West Lancashire District Council West Lancashire District Council West Lancashire District Council West Lancashire District Council West Lancashire District Council West Lancashire District Council West Lancashire District Council West Lancashire District Council West Lindsey District Council West Lothian Council West Lothian Council 138

139 jim Stacey Peter Alan Andy Anne Charlotte Chris Chris Darren Dave David David Debbie Flis dave Tony George Chit Christopher Ruth Marilyn Wendy Linda Mick Jonathan Leanne Rachel Edmund Julie Angela Andrew Esther Emma Michela Paul rachael Miles Anna Ted Julian Gary Melanie Ruth Kathy Zoe James Mairead Roger Mrs Julia Meyrick Rebecca bruce Cougill Box Cordin Pashley chisholm Gault Jackson Riley Falmer Wilby Lawson Slinger Alston Washbrook Wilson Philips Muson Chong Tinker Newton Hallard Taylor Beard Empsall Sadler Brisland Overfield Hopkins Watson Bence Wilkins Leyland Preistley Wells Griffith Phillips Richardson Duckworth Jones Talbot Mawson Hunt Tapping Wilson Cartwright Rushton Farnell Stack Parker Scott Brentall Cotton Building standards manager Project Manager Policy Officer Architectural Technician Sustaianblity Manager HASC Landcsape Planning Officer Senior Sustainability Officer (Planning) Design and Conservation Officer City Development Officer Environmental Sustainability Officer Principle Development Officer Green City Team Leader Biodiversity Officer countryside planning assistant Tree Officer (Planning) Landscape Architect Landscape Architect Landscape Architect Planning Officer Planning Officer Team Leader, Landscape Design Environmental Sustainability Officer Planning officer Principal policy officer Project Officer Woodland Project Officer Landscape Designer Project Officer Project Officer Environment Officer Property Stratergy Landscape Planner Senior Planning Office Contract landscape architect West Lothian Council West Lothian Council West Lothian Council West Oxfordshire District Council West Somerset District Council West Sussex County Council West Wiltshire District Council Westminster City Council Westminster City Council Wigan Metropolitan Borough Council Wiltshire County Council Winchester City Council Wirral Metropolitan Borough Council Wirral Metropolitan Borough Council Woking Borough Council Wokingham District Council Wolverhampton City Council Worcester City Council Worthing Borough Council Wrexham County Borough Council Wychavon District Council Wyre Forest District Council Wyre Forest District Council Brierley Forest Park Visitor Centre Chesterfield Borough Council Ashfield District Council East Midlands Bioversity Partnership Nottingham City council Broxtowe Borough Council Newark and sherwood district council Ashfield District Council Broxtowe Borough Council Derby City Council Derbyshire county council Mansfield District Council Stevenage Borough Council Warwickshire County Council Leeds City Council London Borough of Camden Doncaster Metropolitan Borough Council London Borough of Islington Council South Derbyshire District Council City of York Council London Borough of B & D Manchester City Council London Borough of Islington Council Rotherham Metropolitan Borough Council Nottingham City Council South Gloucestershire Council West Lancashire District Council City of York Council Rotherham Metropolitan Borough Council Rushcliffe Borough Council Ryedale District Council Greater London Authority Barnsley Metropolitan Borough Council Southampton City Council Kirklees Council Manchester City Council Brighton and Hove Council Dublin City Council Southend Council Barking & Dagenham Council Bedfordshire County Council Gloucestershire County Council Leicester City Council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council 139

140 Jon Jackie Jamie Robert James Bill John Richard Gareth Rob Steve David Pratima Steve Robert Carol Ian Ian Maggie Mary Liz Frank Mike Joanna Gary Judith Barry Gylnis Chris Ester Bryan Debbie Micheal Walter Jodie Bradbury Wardle Foot Biggs Biddlestone Shaw Allsop Sandbach Griffiths Cogings Mead Wilson Balaghee Phillipson Twiggs Barnett Stevenson Shuttleworth Bishop Carr Ewbank Leeming Ashworth Rees Purdy Twiggs Joyce Foster Hope Smith Walters Hill Howard Burrows Davis Development Control Officer Improvement and scrutiny officer Sustainability Officer Head service for regeneration Highways Asset Implmentation Officer Senior Planning Officer Planning Assistant Senior Planning Officer Head of Housing Transport Asset Manager Climate Change Officer Principle Planner Flood Risk Management Trainee Senior Planning Officer Environmental services Emergency Planning Principle Environmental Officer Priniple Plannign Policy Officer Project Manager Corporate Property Deputy Director Senior Valuer Cosnervation and design manager Senior Landscape Architect Climate Change Officer Senior Planning Officer Prinicple Planner Climate change manager Climate adaptation project officer Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Cotswolds council Derbyshire County council Derbyshire County council Amber Valley borough concil Chesterfield Borough Council Derbyshire County council Derbyshire Dales District Council Derbyshire County council Derbyshire County council Derbyshire Dales District Council Derbyshire Dales District Council Derbyshire County council Derbyshire County council Deby City Council Bolsover District Council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council North East Derbyshire District Council Derbyshire County council Derby City Council Derbyshire County council Derby City Council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Dervyshire Dales District Council Derbyshire County council Nottinghamshire County Council Leicester City Council Derbyshire County council Lincolnshire County Council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Derbyshire County council Lincolnshire County Council Katie Martin Al Aleksandra Charlotte Sopie Michael O Donnell Dowson Kazmierczar Rose Thomas Glasgow Tameside Borough Council Salford City Council 140

141 Appendix P Example article 141

142

143 Appendix Q Organigramme 143

144 144

145 Appendix R Overview and evaluation 145

146 146

147 147

148 148

149 149

150 150

151 Appendix S Management structure 151

152 152

153 Appendix T Developer s Guide 153

154

155 Green Roof Developor s Guide This document was funded by Life+ and Groundwork Sheffield, in partnership with the Green Roof Centre. Published September 2011

156 Contents Report objectives Introduction Green roof: Fast Facts Economic Analysis Whole Life Cost & Life Cycle Analysis 5.1 Whole Life Cost 5.2 Life Cycle Analysis (or Assessment) 5.3 The difference between WLC and LCA Net Present Value 6.1 How do NPV and DCF work? 6.2 Discount rate 6.3 Problems with a WLC approach Why green roofs influence a building s sustainability How can anyone make money from sustainability? Long term costs & the people factor How can the value of developments be improved? Green roofs and planning approval Green roof definitions Types of green roofs Construction of green roofs 14.1 Types of vegetation used for a green roof 14.2 Biodiverse 14.3 Summary Financial and economic factors for green roofs 15.1 Capital costs 15.2 The product life of a green roof 15.3 Maintenance costs 15.4 Energy costs 15.5 How green roofs can influence yield Process 16.1 Green roofs and Solar Panels 16.2 Green roofs and Solar Water Heating Panels 16.3 Green roofs and Air Conditioning AHUs 16.4 The benefits of green roofs for insulation properties 16.5 Rainwater management 16.6 Benefits of green roofs for amenity 16.7 Urban Heat Island Effect (UHIE) Case studies 17.1 Barclays Tower Canary Wharf 17.2 Paradise Park Children s Centre Barriers to green roof implementation 18.1 Lack of common standard 18.2 Fire hazard 18.3 Maintenance 18.4 Cost 18.5 Structural issues 18.6 Damage to Waterproofing 18.7 Lack of Expertise 18.8 Lack of Policy

157 Tables Table 1 Table 2 Table 3 Table 4 Table 5 Table 6 Table 7 Table 8 Table 9 Table 10 Table 11 Table 12 Table 13 Table 14 Table 15 Table 16 Table 17 Table 18 Table 19 Effect comparison of different Discount Rates Temperature comparisons of Exposed and Green Roofs Effect of efficiency gains on P and L account Comparison of yield and years purchase Comparison of roof benefits Guide to installed cost of different roof types Comparison of the lives of exposed roofs and Green roofs Comparison of NPV of screws in a single ply roof kwh savings from 100mm Green roofs Comparing NPV & Yield for 2 identical buildings, 1 with a green roof Value changes with Discount Rate Study of temperatures under membranes of a conventional and a green roof Comparison of rainwater effects Green roof reduction in Nitrogen and Phosphates The Canary Wharf data Barclay s Tower Financial Appraisal Paradise Park Data Paradise Financial Appraisal Green Roof additional loadings Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Summer roof diurnal temperature range Winter roof diurnal range Impact of green roof on emissions A typical engineered design Comparison of roof build-up Biodiverse roof installed at Sharrow Primary School, Sheffield The Cube live/work development, Sheffield PVs on a white roof Photovoltaics and green roofs, Switzerland Exposed roofs and green roofs with solar panels Sheffield Wednesday football ground 26th June 2007 North Haringey School amenity space on roof Moorgate Crofts Business Centre, Rotherham White Rose Car Park Green roof St. Vincent s Park artist impression Sedum mat area of the roof Barclay s Tower Jubilee Park Canary Wharf London

158 Glossary Cold deck roof The insulation is located on the interior side of the deck. The deck is not warmed by the building interior and ventilation is required above the insulating layer to reduce condensation. In the relatively humid climate of the UK the cold deck roof is generally not a preferred option. Covenant In tenant terms it s the quality of the business and how likely they are to be able to pay the rent for the full lease term. Inverted warm deck roof The insulation is located on the exterior of the roof waterproof layer. The waterproof layer now becomes the vapour control layer preventing condensation between itself and the deck. The thermal insulation protects the waterproof layer from extremes of temperature. The thermal insulation is commonly retained in place by ballast consisting of paving slabs or gravel. Evapotranspiration The combined action of evaporation (of water from the soil) and transpiration (water loss from plants). Substrate Growing medium for the plants and can be made up of various materials including soil, and reclaimed building materials mixed with nutrient material (compost). The key factors are substrate depth and whether it is nutrient rich or poor. Transpiration To give off (water) vapour through the skin (of plants). Warm deck roof Insulation is placed between the exterior waterproof layer and the roof deck (the deck being the surface that supports the waterproof layer and transfers roof surface loads to structural members). A vapour control layer is placed between the insulation and waterproof layer to reduce condensation. No internal ventilation of the roof interior is required. Whole Life Costs The analysis usually using Net Present Value of future inflows and outflows of cash due to a particular asset or change. Life Cycle Assessment Life Cycle Assessment (lca, life cycle analysis or ecobalance) is used to assess the environmental performance of a product from cradle to grave. Net present Value The discounting of future cashflows to present day values. Urban Heat Island Effect (UHIE) The Urban Heat Island Effect is where an urban area has a higher temperature than the surrounding land. It is caused by the reduction in green space through urbanisation and the large amount of hard surfaces that provide high thermal mass and can result in the area of the heat island having its own micro-climate. The Environmental Protection Agency state that on hot summer days, urban air can be 2-10 F (2-6 C) hotter than the surrounding countryside.

159 1. Report Objectives This report aims to demonstrate the economic advantages of integrating Green Roofs into a development and will relate existing data to a UK setting. The recognised methodologies of Net Present Value and Discount Rate are used to demonstrate both the short-term and long-term financial gains to be had from investment in Green Roof technology. Although this report looks primarily at commercial and office developments, the same financial and non financial benefits can be derived for residential apartment blocks and public buildings, in fact any low pitch flat roof. The current thinking on Green Roofs, in relation to key benefits will be reviewed, including: Increasing energy efficiency - cooling in summer, insulation in winter Filtering and cleaning toxins from both air and storm water Retaining rainwater before it evaporates, Delaying storm surges and reducing the likelihood of flooding Reducing urban temperatures and associated smog and low atmosphere ozone Insulating against sound and noise Preserving and enhancing biodiversity Providing aesthetic appeal and green space recreational opportunities Using recycled materials including aggregates and plastics improves sustainability The final section of the report will show how these general benefits can be translated into the following income for developers and building owners: Increased rent Attract better covenant tenants Decrease letting voids Increase the value of a building.

160 2. Introduction It is generally accepted that climate change is happening. The widespread flooding across England in July 2007 served to heighten public awareness of the potential effects and has focused attention on the need to plan and adapt for changing future climates. This approach is termed sustainable development with guidance to achieve it set down in PPS1 of the National Planning Policy Developers have to balance their responsibility to ensure that they reduce their impact on the environment and society whilst still making money. Sustainable development is common-place in rhetoric but difficult to achieve in a cost effective reality. This report demonstrates how we can improve development economics for new and refurbished buildings and at the same time bring environmental and social benefits. The problem usually raised with environmental improvements is that they are prohibitively costly. This report shows how to combine the capital costs and the cost in use to ensure the right decisions are taken with regard to developments. There is an environmental technology that saves money, improves the value of the development, reduces the environmental impact, and provides real benefits to staff. In other words a win/win/win option. Green roofs are that technology and this report demonstrates how installing green roofs on a new or refurbished building will: Increase the value of a development Increase rent Increase yield Reduce the void periods Increase letability Reduce energy consumption Reduce CO2 emissions Remove pollutants from the air Reduce the occupation costs of a building The report also looks at how to value a green roof, what design options are available, how to install them and how to maximise the benefits. Developers need to consider climate proofing their buildings to cope with wetter winters and warmer summers. Our cities will be up to 6 degrees hotter as high density developments lead to the Urban Heat Island effect. The developers able to respond to these challenges and changing customer preferences for greener buildings will maintain a competitive advantage in the marketplace.

161 3. Green Roof: Fast Facts Things you should know about Green Roofs before reading this report: A typical single storey building with a Green Roof and 100mm (3.9 inches) of growing medium would result in a 25% reduction in summer cooling needs and 15% reduction in heating in winter. 1m 2 (10.76 ft 2 ) of grass roof can remove between 0.2 kg of airborne particulates from the air every year. 1 m 2 (10.76 ft 2 ) of foliage can evaporate over 0.5 litres of water on a hot day and on an annual basis the same 1m 2 can evaporate up to 700 litres of water. A Green Roof with a 120mm (4.7 inches) substrate layer can reduce sound by 40 decibels; a 200mm (7.9 inches) substrate layer can reduce sound by decibels. On a summer day, the temperature of a gravel roof can increase by as much as 25 C (77 F), to C ( F). Covered with a Green Roof, the temperature of that roof will stay at 25 C (77 F), saving energy costs. 200 mm (7.9 inches) of substrate with a 20cm to 40cm ( inches) layer of thick grass has the combined insulation value of 150mm (5.9 inches) of mineral wool. Rooms under a Green Roof are at least 3-4 C ( F) cooler than the air outside, when outdoor temperatures range between C (77-86 F). The Possman Cider Cooling and Storage Facility in Frankfurt, Germany yielded a 2-3 year payback for their Green Roof system through savings in heating and cooling costs, as well as in equipment costs, since additional cooling towers had become unnecessary. Green Roofs retain between 50 and 70% of the rain that falls on them; in winter they retain between 25 and 40%. A Green Roof with a 40 to 200mm ( inches) layer of growing medium can hold 100 to 150mm ( inches) of water This report will show how these general benefits can be translated into specific income for developers and building owners: Increased rent Attract better covenant tenants Decrease letting voids Increase the value of a building. We will first look at what an economical analysis can tell us about the inclusion or otherwise of a Green Roof on a development.

162 4. Economic Analysis This report looks primarily at commercial and office developments however, the same financial and non financial benefits can be derived for residential apartment blocks and public buildings, in fact any low pitch flat roof. In every development appraisal an economic analysis takes place, which can be fairly rudimentary or extremely detailed and it can be based on known data or estimates. The analysis will always include the capital cost of the development and an appraisal of the value when complete. Recently developers have been using Net Present Value, (NPV), to assess the value of the project. NPV has a number of advantages as it uses capital cost and the cost of using the building to assess value. This provides a better analysis of the economic benefits of how a development is designed. It makes possible the estimation of the positive or negative impact on the project s profit of any decision the design team or the developer makes. The ultimate value of the project is primarily derived from hard facts, such as the rent and the net lettable area, but it is also influenced by subjective considerations such as the covenant of the tenant and the likelihood of future rental voids. Increasingly values are being influenced by the concept of for how long the building will be satisfactory to tenants. This is logical because the value is going to be based on the number of years that the investor can reasonably expect rental income less any costs incurred along the way. This is the very calculation that NPV does to determine value and can be applied equally to the whole building or a single component. In this section we will look at the various methods of analysis including: Whole life cost Life cycle analysis Net Present Value and what benefits they provide to a developer.

163 5. Whole Life Cost & Life Cycle Analysis We need to look at what Whole Life Cost (WLC), and Life Cycle Analysis (LCA), mean and the difference between. Unfortunately the two terms Whole Life Cost and Life Cycle Analysis are often used interchangeably and, incorrectly, to describe whatever it is that the user wants it to mean. There is also another term in common usage - Life Cycle Costing, which has no universally accepted meaning and can refer to WLC or LCA, or a bit of both, depending on who is using it and the context. We do not use the term Life Cycle Costing in this report however, when used in a development scenario the meaning should always be defined by the user. Both WLC and LCA have well accepted definitions and they describe very different processes that have different uses. 5.1 Whole Life Cost Whole Life Cost is the analysis of all relevant and identifiable cashflows regarding the acquisition and use of an asset. Definition of Whole Life Costs, The Whole Life Cost Forum Where: Cost - may be financial only or may include non financial elements (LCA) Analysis the presentation of the data in a way that is understandable to the reader Relevant - means those costs directly attributed to the asset under review Identifiable - means we have to be able to quantify it in some way Cashflows - are the annual incomes and expenditures for the life of the asset Assets - can be whole buildings or a single small component Acquisition - can mean the construction of a building or the purchase of a component Use - is all costs involved in the use of the asset 5.2 Life Cycle Analysis (or Assessment) Life Cycle Assessment is a process to evaluate the environmental burdens associated with a product, process, or activity by identifying and quantifying energy and materials used and wastes released to the environment; to assess the impact of those energy and materials used and releases to the environment; and to identify and evaluate opportunities to affect environmental improvements. The assessment includes the entire life cycle of the product, process or activity, encompassing, extracting and processing raw materials; manufacturing, transportation and distribution; use, re-use, maintenance; recycling, and final disposal. - Guidelines for Life-Cycle Assessment: A Code of Practice, SETAC, Brussels You will note the difference in language and construction of these two definitions.

164 5.3 The difference between WLC and LCA WLC is essentially an economic analysis with defined meanings and a methodology that provides repeatable results. The definition is tight and precise and not open to much interpretation or influence by the operator. LCA, on the other hand, is wide ranging and allows a lot of interpretation by the operator. In fact most LCA methodologies provide for weighting of the results to highlight aspects that the user considers more important. This weighting means that the results are rarely repeatable as different people have widely different perceptions of each element s importance which will vary the weightings and the result. The author took part in a LCA comparison of land based aggregates versus sea dredged for a project at Heathrow Airport. The analysis team considered the land miles that the aggregates would have to travel, land derived 20 to 40 miles and sea dredged Norfolk coast to West London 140 miles, was similar and had identical weightings. The team also decided that the general impact of a quarry was 5 times greater than the impact of sea dredging on the environment even though it was shown that the sea dredged required more energy to extract and process. This interpretation element of assigning weightings allows the results to be skewed to achieve a pre-determined outcome in this case using sea based aggregates. In summary the results from LCA need to used with care and the results from WLC need to be used with knowledge. This report is focused on demonstrating the financial value of developers incorporating Green Roofs which means LCA is less appropriate than WLC here. WLC uses Net Present Value (NPV) to calculate the outcome of a decision and to understand the results correctly we need look at the process of NPV more closely.

165 6. Net Present Value Net Present Value (NPV) can tell us, very clearly and decisively, if it s more profitable to spend more capital today and lower the cost in use or select a lower capital cost option and accept the cost in use impact. However, typically there are a number of names used which mean slightly different things but are in common use. When users talk about looking at the overall value of a project they usually refer to a Net Present Value (NPV) which is a way of describing the method of Discounted Cash Flows (DCF). When using DCF the answer can be positive, a net present value (NPV) or negative, a net present cost (NPC) which, to confuse things further, can also be expressed as a positive number. DCF is a comparison technique and is used to compare the results of a decision. Therefore the logical spread of results are positive numbers show an income and negative show a cost. We are used to this concept, because we understand that higher positive numbers and lower negative number are the better results. DCF is undeniably considered a black art by many in the property industry but it is a very useful step forward. Before about 1990 the most common way of selecting between capital projects was a simple payback calculation - how many years of profit would it take to pay back the original investment - which unfortunately did not always lead to the best decisions being taken. 6.1 How do NPV and DCF Work? DCF was invented to answer a simple question If I have 2 competing investment opportunities and can only afford to invest in 1, which one should it be? If you were offered these 2 similar capital investments of say 100 each with payback periods of 2 years, 4 years. under the payback method of assessment you should accept the first, but this assumes the different lives of the investments have no impact on the profitability. So let us now add a little more information and see if that changes the decision: investment 1 provides 50 surplus per year but its life is 3 years, investment 2 provides only 33 surplus per year but has a life of 6 years. To understand the relative benefits, and make the decision now, we need to analyse the future cashflows which look like this: Investment opportunity Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Total income nil nil nil Now the logical decision is to go for Investment 2 as it provides a higher surplus for the same investment. Which is why payback often gave the wrong guidance.

166 Discounting the forward value of the inflows adds to the validity of the result by compensating for the time it takes to earn the surpluses. The easiest way to explain Net Present Value is in terms of the well understood principle: the return required by an investor. Let s suppose you have some money to invest, and you have been offered a government bond as an investment (bonds give fixed returns so are sold at a lower amount than the face value). When the bond matures, exactly one year from now, you will be able to exchange it for 100 in cash. The bank issuing the bond is 100% reliable and risk-free so no risk premium needs to be applied. So the question is: how much would you be willing to pay now in order to obtain this bond? Given the choice between receiving 100 today or 100 next year, almost everybody would choose to have the money now. In other words, money today is more valuable than the same amount of money tomorrow. This principle is called the time value of money. The difference in value is not only due to inflation - even if inflation were zero, people would virtually always prefer to receive money now than in a year s time. The main reasons for this are: most people have an expectation that their wealth will be greater in the future, so the relative value to them of a particular sum of money will be correspondingly less in the future money received now can be put to work to earn a return so that, in a years time it will have accumulated in value the benefit of money received now is certain whereas, because there is no guarantee that you will be alive next year, the benefit of money received next year is uncertain. This is the element of risk. Suppose you want to earn 10% annual interest on your investment. You will therefore be willing to pay around 91 for the bond. The present value (PV) is calculated using the formula: Present value = the value of the bond x the required return Which for our example is: Present value = 100 x = So, at a 10% rate of return, the bond is worth today. Another way of saying the same thing is: at a discount rate of 10%, the bond has a present value of This means that, to you today, the value of 100 in 12 months time is So, it can be seen how the future value of money is discounted by a rate that is time-related. Now, consider another investment. This time it is a 1,000 bond maturing in 2 years. But this time you only require an 8% rate of return on your investment. You would therefore be willing to pay the present value today for the bond ( x 1.08 x 1.08 = 1,000). The present value of a future sum of money therefore depends on three factors: how big the cashflows are how far into the future the sum of money will be paid or received the rate of return that is expected or required.

167 To summarise In present value terms, any future set of cashflows, including inflows and outflows, will have a current value depending on the time-period and discount rate applied. For any given discount rate, the present value of a future sum of money is the amount you would need to invest today, at an interest rate equal to the discount rate, in order to obtain that sum of money. In a DCF analysis of a project, each component of the project cash flow is treated as if it were equivalent to a bond - in other words, it is the promise of a particular sum of money at some specific time in the future and therefore carries risk which is included in the Discount Rate. Once you have chosen what discount rate you wish to use, you can calculate the present values of the different parts of the cash flow. If you sum together the annual present values of all the different components of the project cash-flow, the result is called the Net Present Value. On the following page we add more data to our previous example to see if the results change. So let s now add some more data to our earlier example with a 10% discount rate: Investment 1 Discount Discounted Cashflow Capital Cost Year Year Year Year Year Year Total Investment 2 Discount Discounted Cashflow Capital Cost Year Year Year Year Year Year Total The Net Present Value of the 2 investments are: Investment 1 26 Investment 2 49 As investment 2 generates a higher return that is the one that should be chosen. The problem with development projects is that the initial cashflows are usually costs generating net outflows and that the benefits, or inflows, do not start to accumulate until a later date. The longer that time-period or the lower the inflows the less value they will have today. Also the inflows may not be directly to the benefit of the original developer. So having seen what NPV is, what can it do for developers? NPV can tell us clearly if it s better to spend more capital today and make a greater return during the future. Using Green Roofs as an example at a basic analysis level the capital costs are balanced against savings made in the drainage and in reduced energy costs throughout the life of the project. The analysis can add in as many other incomes and costs as the user sees fit. Later in this report we will look at the impact a Green Roof makes on the value of a development and what financial benefits can, and should, be included. Net Present Value function is available in all good spreadsheets and is not difficult to operate once the methodology is understood. We now move onto the variable in a NPV calculation, the Discount Rate, and how to use it.

168 6.2 Discount rate Selection of Discount Rate is very important as 5% and 10% Discount Rates for the same conditions give very different results see table 1 below. While Net Present Value is a very robust approach to analysis with very few areas open to manipulation, it should be acknowledged, however, that a skilled practitioner in NPV can influence the result by selecting an inappropriate Discount Rate. Unfortunately this is the area in which decision makers are less likely to have sufficient knowledge to make their own assessments. The discount rate used to evaluate a project should reflect:- The weighted average cost of the capital WACC, (which is unique to the business concerned) this is the average cost of borrowing to the business and includes bank borrowing and shareholder returns. The risk of the project to the business - the benefit of money received now is certain whereas, because there is no guarantee that you will be alive next year, the benefit of money received next year is uncertain there is, therefore, a risk with any investment and that risk tends to grow with time. The opportunity cost of that capital - money received now can be put to work to earn a return so that, in a year s time it will have accumulated in value. Table 1 Effect comparison of different Discount Rates Discount Rate 5% 7% 8% 10% NPV 24,188 19,307 17,350 14,154 Table 1 uses identical cashflows over 15 years and only the discount rate is changed. The variance between the 5% and 15% discount rate demonstrates the importance of selecting the right rate. In recent studies various rates have been used. Acks (2003) used a private real discount rate of 8% for New York City buildings, while the Treasury Board of Canada (1998) suggested a general rate of 10%. Wong et al. (2004), in a life cycle analysis of the private costs of Green Roofs in Singapore, used a rate equal to the average prime rate (bank interest rate) over the last 10 years which was 5.15%. However, using the average interest rate is not an acceptable method for deciding the discount rate as it has no reference to the cost base of the business making the decision. In the absence of reliable data to assess the Discount Rate the author has found that a rate of 7% provides the right level of comparability and provides sufficient cover for the risk involved. The choice of Discount Rate impacts Green Roof projects as they typically involve significant costs of construction in the present day (ie 100% non discounted costs) and benefits that accrue over the life of the roof, higher discount rates make these projects look less attractive than cases with identical costs and benefits but lower discount rates. For more information on Discount Rates see

169 6.3 Problems with a WLC approach The majority of the construction industry, including major clients such as the Government, focus just on the initial capital cost with no understanding of the links between Capital Costs, Cost in Use and project value. How many times do development teams fight to keep costs to budget and how many times do excellent project requirements get cut out to reduce the overall budget? The project Quantity Surveyor must be instructed to consider cost in use and to complete a Net Present Value analysis for each option selection and decision points. Without this instruction from the client they will have no other option but to be capital focused. The other misnomer to be wary of is value engineering where the normal process is to strip out capital costs without considering either the impact on the cost of use or how that element will affect the costs of other components. However, speculative developers and long term property investors are beginning to understand and to exploit the concept of how green technologies, and particularly Green Roofs, add value to their developments. We look at this in more depth now. This concludes the theory behind financial appraisals and we now need to consider the non-financial aspects of asset selection and decision making.

170 7. Why Green Roofs influence a building s sustainability It is a simple concept that roofs absorb heat; stand on any roof in the summer and the reflected light levels are high and the surface is hot. Similarly go into the loft of any home in the UK and the solar gain and heat transmission is evident by the stiflingly hot atmosphere. By making roofs cooler, designers can reduce the amount of absorbed solar energy, and consequently reduce the amount of heat conduction into buildings. This reduces daytime net energy inputs (Akbari and Konopacki, 20041; Akbari et al, 2001) and the demand for air conditioning. Eumorfopoulu (1998) carried out detailed calculations to examine the thermal behaviour of a planted roof and concluded that Green Roofs can contribute to the thermal performance of buildings. This study further showed that of the total solar radiation absorbed by the planted roof, 27% is reflected, while the plants and the soil absorb 60%, and 13% is transmitted into the soils. Evidently, with a Green Roof the insulation value is in both the plants and the layer of substrates (Eumorfopoulu, 1998). Patterson (1998) also showed that Green Roofs prevented temperature extremes and the insulation value of the soil on the structure lowered the cooling energy costs. Onmura et al. (2001) measured surface temperatures of white roofs and Green Roofs and found that a typical Japanese roof was at 60 C whereas a Green Roof was around 28 to 30 C. Similar studies have been carried out in Germany with a similar 60 C but with a reduction to 25 C. This 35 C reduction is now considered to be the European average. Sonne (2006) used a roof with 50% Green Roof and 50% exposed to compare surface temperatures. They found that there was an average range of; Table 2 Temperature comparisons of Exposed and Green Roofs Roof Type Lowest temp Highest temp Range Time of peak Exposed 8 C 36 C 28 C 14:00 Green 16.6 C 17.8 C 1.2 C 23:00 Sonne also measured the daily minimum and maximum variations. The results are also fairly consistent over the summer and winter months. Figure 1 Summer roof diurnal temperature range Conventional Roof Peak East Conventional East Green Midle Conventional Middle Green West Conventional West Green Temperature F Green Roof Peak Hour of Day

171 Figure 2 Winter roof diurnal range Conventional Roof Peak East Conventional East Green Midle Conventional Middle Green West Conventional Temperature F Green Roof Peak West Green Hour of Day The daily range in temperatures for the exposed and Green Roof is 600 F and 60 F respectively. Large ranges in maximum and minimum temperatures over the 24 hour cycle causes severe heat stress on all the roof components including expansion and contraction and out gassing of volatiles. This also means the surface waterproof covering is more likely to fail early. Reducing the heat load and stress increases all the component s lives and reduces the heat transferring into and out of the building. Additionally the reduced range with a Green Roof allows the building to reach an even heat loss/gain profile. This in turn allows the air-conditioning and heating to be designed for lower extremes and to work at higher efficiency. It also allows the plant to be suitably downsized. The impact on the sustainability of a Green Roof can be demonstrated in graphical form in Figure 3 below. Figure 3 Impact of Green Roof on emissions Strategies Processes Results Cooler Roofs Shade Trees Direct Reduces A/C Use Reduces Demand at Power Plants Less Energy Consumed Indirect Area Sources Emit Less Lower CO2, NOx and VOC Levels Cooler Roofs Cooler Pavements All Vegetation Reduces Outdoor Temperatures Slows Reaction Rates Lower Ozone Levels Source: Banting et al, Oct 2005 p18 Green Roofs lead to lower energy consumption and therefore, through lower generation, to lower CO 2 emissions. It s clear that if there is lower energy consumption then there will be cash savings, but Green Roofs and sustainability can affect developer s income and profit in many more ways.

172 8. How can anyone make money from sustainability? This is a question many developers are asking and it can be difficult to demonstrate until the principles of NPV are understood. Essentially sustainability can provide income or reduced cost and sometimes it can do both. Green Roofs are one of the best examples of increased income, reduced cost and lower impacts on the environment. A win/win option. Often sustainability will produce benefits that translate into future benefits which might be realised by the occupier or long term building owner rather than the developer. However, NPV will demonstrate those future benefits which can increase the present value of the development by improving rent and yield and reducing void periods.

173 9. Long-term costs & the people factor Recent and widely reported research into office accommodation has identified the relationship between capital cost, the cost in use and the cost to the business of assets as: Capital Cost Cost in Use Business Costs Source: The long term costs of owning and using buildings - published by The Royal Academy of Engineering (November 1998). What this means is that to operate and maintain the building will cost 5x the capital costs over the life of the building. However, the cost of using the building for the occupier is 200x the capital costs. However, as we have seen most developers are very focused on build cost, i.e. the initial capital cost. This is due to the way most developments are funded with two funding sources: 1. Development capital. This is a short term funder who takes the risk while the building is constructed and while the developer finds tenants. The cost is around 2% higher than the long term funding. 2. Once the building is occupied the short term funds are replaced by a long term funder. All developers have good sales and marketing teams that are focused on attracting tenants and can advise the design team on what the target tenants will want. What most developers lack is the ability to maximise the value of the final product. Critically these relationships appear to work in reverse as well. So, if a developer just focuses on lowest capital cost, ignoring performance and cost in use, the effect of reducing the capital cost by 10% could be: Capital Cost Cost in Use Cost to Business k + 500k + 20m This means that a reduction of 100k in capital cost which cuts performance can cost an additional 550k in building running and 20m in occupation and employment costs for the occupying business. The real reason we build buildings is to provide a warm, dry, safe place for an organisation to employ people, to do what it does, to earn profit. In simple terms a company employs 100 people. If a building provides an efficient working place then the benefits impact the bottom line immediately with no intervening costs Table 3 Effect of efficiency gains on P and L account Efficiency par 5% 10% Employees Earnings 3,500,000 3,675,000 4,042,500 Earnings/Employee 35,000 36,750 40,425 Increase in proftability 0 175, ,500 In this example, a 5% efficiency brings 175,000 additional profit which is attributable to each year of the building s life.

174 This workforce efficiency can be generated in a number of ways but an obvious example is a building with inefficient air-conditioning, which will soon over heat, resulting in staff being unable to work efficiently in temperatures over 25 C. An actual example of this is a newly refurbished Government office in central London where one of the client requirements was to reduce energy consumption. They opted for a naturally ventilated building with no air-conditioning however, in the summer the temperatures exceed 280 C and now all desks have 1.5kWh personal fans adding 1.5MWh per year to the building consumption. With urban temperatures rising the building will fail on more days a year. Once the impact on the cost in use and the building user is understood the impact on development income starts to become more obvious. However, there are a few problems still to overcome.

175 10. How can the value of developments be improved? Buildings are valued by combining the hard facts with soft issues, such as letability and local competition. The hard factors can be broken down to: The size in square feet. That is the gross net lettable, remove common parts and toilets and only measure the space the tenant can use. The rent. This is the amount of rent stated on the lease excluding service charge. So stage 1 is size x rent which gives gross income (earnings) per year. An example is a building with 1,000 sqft net letable and a tenant at 20 /sqft/year. So the earnings are 1,000 x 20 = 20,000 each year of the lease. However, to value a building we need to multiply the income per year, the 20k from above, with a factor that reflects the security provided by the building to ensure future letting potential, the future cashflows which is an NPV calculation. Factors that affect the value: Length and type of lease. Some valuers and purchasers favour 25 year FR&I (fully repairing and insuring) the traditional UK institutional lease. But it is now a bit out of favour with a lot of tenants and purchasers. With a 10 year lease the tenant has the option to leave without obligation and the owner can refurbish and increase the rent and hence value but this will mean they have rental income voids. The creditability of the leaseholder. This is called the covenant. A blue chip FTSE listed tenant is deemed less risky than a small business. The reletability of the building. This is a factor to cover how easy will it be to re-let the building at the end of the lease or when the tenant disappears. There are lots of things that affect this such as floor to ceiling height, flexibility, location, elevation treatment (will it look nice in 10 years?) the quality of local competition and how will the decision makers and their employees like the building. The maintenance profile of the building. If good quality design and materials are used the cost of maintenance is reduced and higher positive cashflows are generated in the future. This is translated into a higher NPV and current valuation. A good example is the roof s waterproof layer. A built up roof is cheap but will last only 10 years or so whereas a single ply membrane will last 25 years. So the built up roof is replaced twice during the single ply life. The impact of replacing the roof is substantial which is why the additional capital cost is more than offset by the increased value of the development. User acceptability of the building. If the building is unacceptable to the users, for any reason, the tenancy is at risk and the relettability is lowered.

176 Currently there is a big push from Government to avoid air conditioning, as a way of reducing energy consumption, and use naturally ventilated systems. Naturally ventilated buildings are like the old electric storage heaters - they were fine for part of the day but were too cold or too hot the rest. The offices with natural ventilation systems are not comfortable places for staff to work in. This is now widely known amongst occupiers so if there are 2 competing buildings, one with and the other without air-conditioning, the air-conditioned will be occupied first. So the value of naturally ventilated buildings is much lower than air conditioned or good comfort cooled. This is an example of how focusing on one element of sustainability, energy reduction, and ignoring the people elements leads to failure. Therefore, generally the better the building the higher the value. The value is determined by taking the fixed criteria, the square feet x the rent, and multiplying it by a number of years that reflects its value compared to other similar buildings. This is known as years purchase and is a measure of quality as well as value. This years purchase must also balance the price paid to the developer with the time left for the investor to make his return. The basic value equation is: net lettable space x rent x no. years purchase = value However, years purchase can be expressed as a % called yield, where yield is the inverse fraction. yield % = 100 years purchase To convert a yield to years purchase use this calculation. years purchase = 100 yield Many in the property world use yield and years purchase to provide a shorthand comparative value and quality descriptor. The following table demonstrates the values from a range of yields for the same 10,000 income. Table 4 Comparison of yield and years purchase Yield % 5% 8% 10% 12.5% 15% Year s Purchase Value 200, , ,000 80, As the yield is an inverse you will see that the lower the yield, the higher the value. This is counter-intuitive and therefore not widely understood. However, if a developer says something will reduce the yield by a half a percent you now know that it will increase the number of years purchase and increase the income! Property investment funds have very quickly identified that tenants do not stay in buildings that do not provide the right working environment for their staff. In our example, therefore, a building with poor natural ventilation will be harder to let, now and in the future, and the number of years purchase (yield) offered will be lower. Conversely Green Roofs, which have a wide range of financial, environmental and social benefits, provide a significant positive effect on the value of the development. We now need to look at Green Roofs in more detail.

177 11. Green Roofs and Planning Approval From a planning perspective, Green Roofs can help to satisfy a range of needs which will increasingly have to be considered as part of a planning application. Sheffield s Head of Planning, Les Sturch, has stated: By using a Green Roof an applicant can provide benefits which satisfy a number of planning policy requirements at the same time; for instance sustainable drainage, reduced energy consumption, improved biodiversity and better air quality. We are increasingly expecting developments to demonstrate holistic approaches to dealing with these environmental issues. Whilst adding a Green Roof will not ensure a successful planning application it will add to the credibility and desirability of the building in the eyes of the planning office.

178 12. Green Roof definitions A succinct definition of a Green Roof is found on Wikipedia. A Green Roof is a roof of a building which is partially or completely covered with plants. It may be a tended roof garden or a more self-maintaining ecology. Ref en.wikipedia.org/wiki/green_roof A Green Roof development involves the creation of green and living areas on top of a man-made structures. This green space can be below, at or above grade (ground level), but in all cases the plants are not planted in the ground but on top of a structure over a useable space. Many ground level gardens are in fact Green Roofs over car parks or amenity space. (Pictures FTW Gardens and Canary Wharf). Green Roofs can provide a wide range of public and private benefits. Green Roof systems may be engineered, with proprietary drainage layers, filter cloth, growing media and plants in pre grown mats by the roofing supplier, or each component of the system may be installed separately in layers by a Green Roof contractor or even the original ground worker. Green Roofs can be used in many applications, including commercial, industrial, government and residential applications. In Europe, they have been widely used for many years for their storm water management and energy savings, as well as their aesthetic benefits.

179 13. Types of Green Roofs Green Roofs refer to the environmental benefits of plants on roofs, rather than to the colour green. In fact with many roofs planted for their biodiversity they are anything but green, often being referred to as brown roofs as they change through the seasons This section will provide descriptions of the types of roof and their differences, usually soil depth and planting regime. Green Roof is a generic term that has evolved since the early 1900 s and is now often called a living roof. Green Roofs are primarily divided into extensive and intensive categories. Intensive Green Roofs For intensive Green Roofs, the growing media is fairly deep - usually more than 300mm and supports shrub and tree growth. A roof top garden or a patio is an example of an intensive roof. The saturated weight is 3.3kN/m 2 or more and irrigation is necessary in most cases. They require a lot of maintenance, like any other well-kept garden does. Intensive roofs provide real social benefits for building occupiers with recreational space. Semi-extensive Green Roofs Usually mm inches deep with a saturated weight of kN/m 2. Whether irrigation is necessary or not depends on the regional climate and on the kind of plants that are used. Shrubs, perennials, herbs and grasses can be used on semi-extensive roofs and they are usually accessible to staff. They can include hard paved areas and are attractive to a wide range of invertebrates. Extensive Green Roofs Typically mm deep with a saturated weight of kN/m 2. They are ideal for the growth of drought-tolerant plants, particular succulents like Sedum. They don t need irrigation and only little maintenance. Due to the low maintenance, they are often the roof of choice for building owners looking to reduce costs and improve the environment.

180 The extensive roof type can be further sub-divided into: Sedum plug planted or mats is often used when aesthetic or visual impacts are important. A sedum roof tends to be visually consistent throughout the year. Some suppliers offer roofs, primarily sedum mats, with thicknesses of around 50mm. It is generally accepted that roofs with less than 60mm of growing medium will not survive and will require extensive maintenance and replanting. Biodiverse using a number of local plants and alpines with locally sourced growing mediums, where possible. The visual aspect will change with the seasons particularly during winter. Biodiverse roofs are more attractive to wildlife and can be designed to attract and sustain local birds, insects and invertebrates. Extensive Green Roofs normally have a thinner growing medium but can offer as much amenity and recreation if planting is designed rather than merely specifying a sedum mat. A semi-extensive roof in Grey s Inn Road, London installed 2 years ago has a simple paved area with plastic chairs and tables for staff. It is in great demand all day and one employee said he came in an hour early to have coffee on the roof and prepare for the working day. They are usually less costly to install than intensive Green Roofs and are less costly to maintain, as they do not require mowing, irrigation or any other form of intensive management. Extensive Green Roofs generally provide greater biodiversity interest than intensive roofs. Usually they are planted with or colonised by, mosses, succulents, wild flowers and grasses that are able to survive on the shallow low-nutrient substrates that form their growing medium. Commercial systems in the UK generally use sedums (Sedum spp.) as the principal plant species in the vegetation layer. Sedums, which are low growing succulents, are often used as they are drought and wind tolerant, form a dense covering and can be very visually attractive. These sedum based systems generally come in two forms: a blanket/mat system, a substrate-based planted or hydro seeded system. Often blanket systems are the only type that can be used on existing buildings due to load restrictions. On new build, however, where additional structural loading can be taken into account during the design and construction process, substrate systems (which can comprise recycled materials) are preferred because of the greater environmental benefits they bring. The construction of the roofs will be discussed further in the next section.

181 14. Construction of Green Roofs Essentially, a Green Roof system consists of layers that imitate natural processes of evapotranspiration and filtration, and also protect the building and roof. The basic components are: a waterproof layer a root repellent membrane the drainage system (to drain excess water) a filter cloth (to allow water to drain but prevent soil escaping) soil substrate seeds and plants Figure 4 A typical engineered design Vegetation Growing Medium Drainage, Aeration, Water Storage and Root Barrier Insulation Membrane Protection and Root Barrier Roofing Membrane Structural Support Figure 5 Comparison of roof build-up Gravel-ballested Roof Gravel Protection Layer Waterproofing Moisture Barrier Insulation Seperation Layer Source; England et al 2004 Green Roof Substrate Filter Fabric Drainage Protection Layer Waterproofing Moisture Barrier Insulation Seperation Layer

182 14.1 Types of vegetation used for a Green Roof Vegetation is the most important layer of a Green Roof. Plants add aesthetics and also determine the success or failure of the project, depending on their hardiness. Biodiverse (extensive) roofs offer the easiest and lowest cost option. Many seed suppliers offer local wild flower mixes which can be as low as 0.19 per m 2. The downside is the roof may take 2 or 3 seasons to become established. However, the additions of annuals such as such as cornflowers will add colour and interest while the roof matures. Any well designed roof, of any type, should include timber and stones to encourage invertebrates to colonise the roof. Of course the extreme solution is to allow the roof to self seed which is especially effective if reusing the top soil of an existing brown field site. Although, this make take several seasons to mature and may suffer from soil erosion if not planted with grasses or similar. Although plants are the most vital component of an extensive Green Roof, they are often the most neglected due to cost concerns. Plant plugs with fully established root systems quickly spread out their roots horizontally and form a dense vegetation mat in a few growing seasons. Plant cuttings (mostly from sedum) can also be spread over the soil layer. While these cuttings may eventually form roots, it can take twice as long before the roots can actively hold the soil in place, prevent wind erosion and use water. From an initial-cost perspective, plant cuttings are more economical because they are less labour intensive to install. However, the survival rate of cuttings is only about 50%, compared to 80% for plant plugs with established root systems reducing the whole life cost benefit as if half the plants need to be replaced within the first year, the apparent cost advantage quickly disappears. The plants most commonly used in sedum roofs are succulents and other low growing plants that are capable of storing water in either fleshy leaves, bulbs or roots. Plants successfully used in shallow soil beds on roof surfaces include various species of sedum, sempervivum, creeping thyme, allium, phloxes, anntenaria, armeria and aubrieta, as well as numerous others. What makes these plants good Green Roof candidates is their ability to adapt to alpine conditions with little soil, no water, high winds and high sun exposure. These plants have to be real survivors. It is also advisable to include native grass seeds over a newly planted roof because the seeds will germinate quickly and stabilise the soil layer until the Green Roof plants start to spread. However, this adds to the appearance changing seasonally and during wet and dry periods. Grasses will grow during wetter periods, and the alpine natives will flourish and display their flowers during long hot and dry summers. Mosses should be avoided as Green Roof vegetation. While their sponge-like forms do soak up and retain a lot of water, they can pose a fire hazard in a drought. Intensive roofs will use any plant found in gardens today and range from ornamental trees to lawns but this increases the maintenance cost and they must be extensively irrigated in dry spells.

183 14.2 Biodiverse There is a type of vegetation that is growing in popularity often called Biodiverse which uses a number of local plants and alpines with locally sourced growing mediums, where possible. All types of construction can be used for Biodiverse roofs. These roofs often include a local wild flower mix and so the visual aspect will change with the seasons particularly during winter. Biodiverse roofs are more attractive to wildlife and can be designed to attract and sustain local birds, insects and invertebrates. Figure 6 Biodiverse roof being installed at Sharrow Primary School, Sheffield (This is currently the largest biodiverse roof outside London) Source: The Green Roof Centre 14.3 Summary Table 5 Comparison of roof benefits Water Attenuation Water Runoff Energy Reduction Biodiversity Maintenance Sustainability Engineered Sedum Mat Sedum Extensive Biodiverse Intensive Naural Sedum Mat Sedum Extensive Biodiverse Intensive to to to to Medium Medium Very Low Very Low Very High Medium Medium Very Low Very Low Very High Poor - Very Good In considering the cost benefit analysis of any project it is important to establish the basic parameters which are reviewed fro Green Roofs in the next section.

184 15. Financial and economic factors for Green Roofs The cost benefit analysis of a Green Roof has a number of factors that can affect the result. This section will look at these before we move onto the analysis of some typical roofs Biodiverse There has been some debate recently over the costs of installing Green Roofs. The cost is very project specific however, we offer some guidance for approximate prices in the table below. Engineered roofs are designed and installed by the roofing supplier and natural roofs are designed by a specialist and can be installed by the site groundworker: Table 6 Guide to installed cost of different roof types Engineered /m 2 Cost /m 2 Natural Construction /m 2 Cost /m 2 Warm roof expose Sedum Blanket Sedum Plug Biodiverse Inverted Roof Shingle Paving Sedum Blanket Sedum Plug Biodiverse Table 6 uses a single ply membrane roof as the base cost and shows the additional cost for the different Green Roof build-ups. Note that for an inverted roof, replacing the paving with a natural Biodiverse roof means no additional cost The product life of a Green Roof The life of a Green Roof is often hard to define, Acks (2003), states that a Green Roof will at least double the life of the waterproofing layer when compared to a normal exposed roof. This doubling of the life of the waterproof layer is now widely accepted in the UK and European roofing industry although it is not currently reflected in standards or warranties. Table 7 Comparison of the lives of exposed roofs and Green Roofs Built Up Mastic Single Ply Metal Exposed (years) Green Roof (years)

185 When assessing the life of a compound product, such as a roof, the selection of the components needs to be addressed to ensure maximum financial benefit is achieved. For example the screws used to mechanically fix a single ply roof have different lives depending on the material. However, they have little impact on the overall initial capital cost. The life of an alloy screw is between 10 and 15 years whereas a stainless steel screw is lifed at 40+ years. So to reduce the initial cost marginally the developer requires the subsequent owner to refurbish the whole roof 10 to 15 years earlier than should be required. The NPV comparison is in table the following below: Table 8 Comparison of NPV of screws in a single ply roof Cost NPV Stainless steel screws Alloy screws + 500k + 20m This means that to save 5,000 capital cost the owner of the building has to pay out for substantial remedial and replacement work between 10 and 15 years later Maintenance costs Maintenance costs are divided into two categories, annual and cyclical. Annual costs are incurred every year and cyclical are recurrent costs but outside the annual cycle. For example annual costs will include outlet inspection and cleaning whereas cyclical will include replacement of the waterproof layer at the end of its life. The maintenance costs are varied by the type of roof. For extensive roofs, previous studies indicate little difference between Green Roof and standard roof maintenance costs. Acks (2003) for example, assumed $0.60 per square foot for Green Roofs and $0.10 per square foot for standard roofs without any data, and Wong et al. (2004) assumed identical annual maintenance costs for standard (exposed roofs) and inaccessible Green Roofs. The article pointed out that an exposed roof required more frequent replacement of the waterproof layer. Today the UK industry accepts that the annual maintenance cost of an extensive roof and an exposed roof is generally the same and that the life of the roof waterproof covering is doubled. In contrast intensive roofs require more maintenance as they are equivalent to a garden or park and plant selection has a big impact on maintenance costs.

186 15.4 Energy costs All previous studies into Green Roofs have derived energy savings but the calculation of the benefits vary enormously. Many studies relate the savings to a monetary value and the difference between the values in Acks 2003 and Wong et al is in excess of 100%. This a fairly unhelpful method as the energy saved should be measured in definable units, kilowatt hours (kwh), without the addition of variables such as cost/kwh. The actual amount of reduction is building and location specific. However, there is now a number of good quality studies that have been completed, on broadly similar 100mm deep substrate roofs, that provide consistent data giving upper and lower figures, Table 9 kwh savings from 100mm Green Roofs Location kwh/year/m 2 Toronto 4.15 Germany 4.0 Barclay s Tower Canary Wharf London Notes on Table 9: 1. The savings are averaged over the year 2. Depth of substrate is slightly lower at 80mm The data from Barclay s Tower is particularly valuable as it was a retrofit sedum mat roof where there is 3 years of records without the Green Roof and for each year since its construction. The variation between the results can be due to a number of factors such as location, exposure and type of heating and cooling used. Unfortunately we are unable to provide a simple one size fits all energy saving amount/m 2 but the range is now fairly consistent across studies. In the next section we look at how these factors combine to improve the value of the development.

187 15.5 How Green Roofs can influence yield In section 10 we looked at factors affecting yield. Green Roofs can increase the value of a development because they improve all the factors considered in setting the years purchase and therefore yield: Lower energy costs over the life of the building Lower refurbishment costs of roof by extending waterproof layer life If the roof is occupier accessible then there is significant employee benefit Provides a Planning benefit Increase rental value Decrease void periods Will increase the yield applied in valuing the development Reduced constructor costs if considered early enough and the design is adjusted to maximise potential benefits. Charlie Green, Director of The Office Group, owners and managers of 175 Gray s Inn Road, London WC1 is unequivocal in attributing the reduction in voids on his Green Roof. These offices have enjoyed a faster take up of space than in our other buildings. This is directly attributable to having the roof,- with a number of tenants stating they preferred us to our competition because of the Green Roof, with some even enduring long commuting journeys In essence a building with a Green Roof will have a higher Net Present Value and that translates into a higher years purchase for valuation purposes. If we compare 2 buildings with the same 10,000 sqft floor area and rent of 250,000; 25 year FR&I lease with 10 year break clause, and a building life of 35 years. Table 10 Comparison of NPV & Yield for 2 identical buildings 1 with a Green Roof Building 1 Building 2 Green Roof Rent pa Void Energy pa Roof referbishment Net Present Value Yield Yield Improvement No 250,000 6 months 30, ,000 (Year 15) 963, % Yes 250,000 3 months 24,000 None 1,212, % 0.48% Data for table 1 Building 1, no Green Roof energy cost 30,000pa 6 month void in year 10, 150,000 roof recover in year 15. Building 2, Green Roof, 20% saving on energy 24,000pa, 3 month void in year 10, no roof refurbishment costs. This supports the proposition that the use of a Green Roof can increase value and improves yield by 0.5%. Varying the rent and cost of construction maintains a consistent 0.48% improvement. However, as the DCF theory predicts, changing the Discount Rate does change the yield for a Green Roof, as table 10 below illustrates. Table 11 Value changes with Discount Rate Discount Rate 4% 10% Improvement in Yield 0.48% 0.80% Absolute value improvement 120, ,000

188 16. Process To maximise the benefit to the developer and the environment, the Green Roof should be included in the client brief and designed from pre-inception. Only then can the design team design their components to take advantage of the effects of a Green Roof. The two main areas of impact are: Drainage - reduced runoffs allow smaller and fewer rainwater outlets with less surface water to dispose of. This leads to lower cost drainage, which when combined with SUDS, can reduce the offsite requirements to zero. Mechanical and electrical - with lower thermal gain in the summer and loss in the winter the cooling and heating loads are reduced and the designs can be more effective and economical. Also the use of Green Roofs provides higher efficiencies in the Air Handling Units and Solar Heating. However, both of these benefits are difficult to ascertain in financial terms as they require an alternative design to be completed and so far there has been limited research that has attempted this. Current research appears to be lacking in terms of quantifying other benefits of Green Roofs, Banting et al (2005) sums up the research into costs and benefits very succinctly; Researchers have provided empirical evidence of benefits... However, many of these benefits are very dependent on the specific Green Roof designs implemented on buildings. Such results cannot be easily extended to typical Green Roof installations without having an impact on other benefits. The Eastside Report for Birmingham states that there are drainage gains to be made where Green Roofs are incorporated early. However, their attempts at reducing the cash gain to a % of building costs was not successful as the volume of a building may vary substantially for 2 similar roof areas. Consider the two case studies Barclays Tower (over 200M build cost) and Paradise Park (1.2M). The Green Roofs were 850m 2 and 400m 2 respectively and would constitute % and 1.8% of build costs. The current traditional design team usually does not include anyone qualified to design or supervise a Green Roof. It will be necessary to include these following skills: Substrate and drainage layer design Planting regime. A good Green Roof design will balance the benefits of the Green Roof and the costs of the additional structural requirements, if any. The specialist Green Roof consultant should be appointed at pre-inception and they must be fully integrated into the team as a key member, otherwise the benefits of a Green Roof will be at risk. However, not all roofs need to be extensively designed, they can be very simple: Figure 7 The Cube live/work development, Sheffield Source: The Green Roof Centre

189 16.1 Green Roofs and Solar Panels There is a perception that a building can either have Green Roofs or solar production at roof level but not both. In fact there is substantial evidence from Germany and the US that the use of both solar or photovoltaic panels (PVs) and Green Roofs provides dual benefits in terms of energy production and energy saved. The Green Roof element increases the efficiency of solar production by reducing fluctuation of temperatures at roof level, the diurnal effect (see section 8), and by maintaining a more efficient microclimate around the solar panels. The current evidence is based on data from PVs but is equally applicable to solar water heating and the efficiency of air conditioning plant. We have seen that the temperature at 1m above an exposed roof can rise to 600C this causes the air to rise causing a turbulent heat haze over the roof. Everyone has seen the wavering effect of looking through a heat haze and it is this interference, occlusion, with the passage of sunlight which reduces the effective amount of sunlight striking the solar collectors surface lowering the energy conversion. Figure 8 PVs on a white roof Gregg et al. while researching PV efficiencies for United Solar Ovonic LLC, found the performance of photovoltaic panels is lowered by 0.5%/ºC above or below 25ºC. Therefore at 600ºC the efficiency is reduced by 17.5% affecting the payback period and economic viability of PVs. Figure 9 Photovoltaics and Green Roofs, Switzerland However, the use of a Green Roof maintains the ambient temperature at roof at about 25ºC allowing the PVs to work at optimum efficiency Photos: Livingroofs.org

190 Figure 10 Exposed roofs and Green Roofs with solar panels If we bring these two pictures together, it s fairly obvious how hot the uncovered roof can be and it is easy to appreciate how a Green Roof conditions the air and improves the efficiency of solar energy collection panels Green Roofs and Solar Water Heating Panels Solar water heating panels are the most cost effective method of solar energy collection and they benefit the same way PVs do when the air around them is cool and interference free. Using solar water heating panels on a Green Roof ensures the maximum return on investment and maximum production of hot water for the solar heating array Green Roofs and Air Conditioning AHUs The air handling units of an air-conditioning system are usually found on roofs. However, we have seen that on hot summer days the air temperature 1m above the surface can be over 400C which means the air temperature has to be reduced by about 220C before it can be used. However, a Green Roof means the temperature above the roof remains around 250C which means the AHUs only have to reduce the air temperature by 70C, which means they use less energy and can be smaller.

191 16.4 The benefits of Green Roofs for insulation properties Green Roofs have a substantial thermal mass and provide a moderate insulation value depending on the season. These combined properties significantly reduce diurnal temperatures at the boundary between Green Roof and building structure (the diurnal temperature being the daily maximum to minimum temperature range). The diurnal temperature range for a conventional construction warm-roof waterproof layer can be very large; for example, the surface of a typical bitumen waterproof layer may exceed 50ºC during a sunny summers day, whilst falling to just above 0ºC at night. A roof with a low level of insulation below the waterproof layer will allow the space below to heat up quickly in hot, sunny weather. The increased internal temperatures in the floor below the roof contribute to making the internal building environment uncomfortable for the buildings occupants. Overheating can lead to increased use of air-conditioning, which in turn will lead to increase in energy consumption. During cold weather, the opposite effect applies, resulting in a demand for extra heating of the floor directly below the roof and, hence, increased energy consumption. The energy used for heating and cooling has a financial as well environmental impact. High temperatures in top floors of buildings also cause the man-made components of the building to emit volatile elements which can have a detrimental effect on the building occupants, often referred to as sick building syndrome. Building products that can be affected include: Floor coverings carpets, vinyl tiles Wall coverings paint, papers Suspended ceilings Furniture. The Green Roof has the same energy providers as a conventional roof, but it has the additional energy consumers of evapotranspiration and photosynthesis. Unlike a conventional roof, the Green Roof is a living system that reacts to the environment in a number of important ways: Water is stored within the substrate and is utilised in evapotranspiration by the vegetation layer; this process uses up a considerable proportion of the incoming solar radiation in comparison to a non-green Roof. The Green Roof has a large thermal mass, which stores energy and delays the transfer of heat to or from the building fabric. Plants absorb solar radiation for photosynthesis converting CO2 to oxygen. Plants also loose water through their leaves to cool themselves. Evaporation from water stored in the substrate cools the surface and area above the roof. The plants provide protection from wind cooling by disrupting air flow across the surface. Plants have a higher albedo (solar radiation reflectivity) than many standard roof surfaces The use of a Green Roof compared to conventional surfaces can have a significant impact on the energy balance within a given building and on the immediate environment surrounding the building. This is particularly relevant if a building has poor insulation and poor ventilation, which can lead to, increased use of air conditioning and therefore increased energy use. Studies have shown that the membrane temperature beneath a Green Roof can be significantly lower than where the membrane is exposed. Table 2 shows the average temperatures under the membrane of a conventional roof and of the same membrane under a Green Roof in a study undertaken at Nottingham Trent University in 2005.

192 Table 12 Study of temperatures under membranes of a conventional and a Green Roof Winter Summer Mean Temperature 0 C 18.4 C Temperature under membrane of conventional roof 0.2 C 32.1 C Temperature under membrane of Green Roof 4.7 C 17.1 C Source: This correlates with the Liu study, which compared a conventional roof system with a Green Roof system. The average daily energy demand for space conditioning caused by the reference roof system was 20,500 BTU to 25,600 BTU (6kWh to 8kWh). However, the Green Roof system s growing medium and plants modified the heat flow and reduced the average daily energy demand to less than 5,100 BTU (2kWh) a reduction of more than 75%. Reducing the temperature of the roof covering improves the energy efficiency and there are a number of different ways a Green Roof can be constructed to realise the benefits Rainwater management When rain falls on forested and open, undisturbed land, water goes through its natural cycle and water is taken up by the plants, (transpiration), evaporates or percolates through to lower levels. However, in urban and metropolitan areas, with buildings and streets, the hard landscape and drainage systems mean that the evapotranspiration and percolation is reduced and the run off significantly increased. Green Roofs move back towards the structure and water retention profile of the natural environment. When Green Roofs are combined with SUDS the profiles become very similar indeed. Table 13 Comparison of rainwater effects Natural Urban Green Roof Evaporation & transpiration 40% 15% 45% to 70% Shallow aquifers 30% 5% 20% to 45% Deep aquifers 30% 5% 0% to 10% Run off Effectively 0% 75% 10% to 0% shallow aquifers is the depth of soil that feeds plants, evaporation and transpiration often called evapotranspiration returns water to the atmosphere The CIRIA (2000) report assumes that for design purposes a Green Roof provide a reduction equivalent to 30-50% annual runoff values. The Environment Agency generally looks for new developments to attenuate surface water run-off back to the same as the original green field rates where possible. The usual method to achieve this is by providing storage below ground but this is an expensive option and although rates vary the average is between 800-1,000 per cubic metre of storage volume provided. To offset the reversed rainwater runoff patterns in urban areas, communities build costly drainage systems. While rainwater collection, storage and treatment systems deal with the impacts of sealed surfaces, they fail to address the source of the problem. In many cases, runoff is directly drained - untreated - into open water bodies and receiving streams, significantly increasing their pollution levels.

193 The combined impact of ongoing development within urban areas and climate change has created higher peak storm water flows leading to an increased occurrence of downstream flooding and pollution. Figure 11 Sheffield Wednesday football ground 26th June 2007 Source: The Guardian web site As a consequence, Sustainable Drainage Systems (SUDS) are now required to minimise the impact of both new and existing developments. They are designed to manage the adverse environmental consequences resulting from urban storm water runoff, and to contribute to environmental enhancement wherever possible. The use of Green Roofs can provide a essential role in achieving this as they successfully achieve source control, which is the fundamental concept of SUDS, i.e. the control of rainfall at or as close as possible to its source. Around 30% to 40% of rainfall events are sufficiently small that there is no measurable runoff taking place from greenfield areas (it all infiltrates or evaporates). In contrast, runoff from developed areas takes place for virtually every rainfall event. This means that streams and rivers are more subject to overload. In addition, whereas for greenfield areas small events would be treated through natural filtration processes, development runoff can flush surface pollutants directly into the receiving waters. Where it is possible to provide replication of the natural behaviour of a greenfield site (described as interception storage) then this should be provided. By using Green Roofs as a source control technique, the volume of runoff entering the underground drainage system, and thus the amount of storage capacity required within this system, can be reduced considerably. This is particularly important in dense urban developments where space for surface level SUDS components such as ponds and wetlands will be limited. It is also an important consideration when looking at the true cost implications of installing a Green Roof as the reduction in underground drainage infrastructure should be taken into account as well as the reduced number of downpipes and the smaller pipe network, etc. When rain falls on a Green Roof it will first pass into the substrate and possibly pass through until the absorbency of the soil is activated (although through-flow will generally be low). It is then adsorbed by the substrate (and possibly the drainage layer) and taken up by plants in the same manner as on a greenfield site. For most small storm events the volume of rainfall is removed by evapotranspiration. Only when the soil is fully saturated will water percolate through to the underlying drainage layer in significant quantity. Livingroofs.org identify the processes involved in the operation of a Green Roof as: Retention of rainwater in substrate and drainage layers Uptake of water and release by plants as vapour (transpiration) Uptake of water and biochemical incorporation by plants (photosynthesis) Evaporation from substrate due to wind and sun

194 There is a significant amount of published information that demonstrates the performance of Green Roofs in attenuating storm water runoff by reducing peak flow rates and volumes. Although there is a variation in performance, depending on rainfall patterns and location, this is no different to other SUDS components such as pervious pavements, or even greenfield catchments. The benefits of a Green Roof in terms of drainage can be summarised as: A Green Roof will typically intercept the first 5mm and more of rainfall (i.e. provide interception storage). The amount of storm water stored and evaporated is primarily dependent upon the depth of the growing medium and type of planting. In the summer a Green Roof can typically retain between 50% - 70% of the runoff. It has been demonstrated in Germany, between 40% - 100% of rainfall can be retained depending on the season. 75% of rain falling on extensive Green Roofs can be retained in the short term and up to 20% can be retained for up to 2 months. As the rainfall events become longer or more intense, the positive effect of a Green Roof remains as there is still a significant reduction in peak runoff rates. This increase in the time of concentration means that a Green Roof will be beneficial throughout a wide range of rainfall conditions. The above benefits collectively mean that by incorporating a Green Roof into new development, there will be a reduction in the amount and cost of the overall drainage infrastructure required to serve that development. Green Roofs retain, bind and treat contaminants which are introduced to the surface either as dust or suspended/dissolved in the rainwater. A recent London Ecology Unit publication reported that 95% of heavy metals are removed from runoff by Green Roofs and nitrogen levels are also be reduced. In addition, Auckland Regional Council advise that Green Roofs are accepted as removing 75% of total suspended solids. Their study showed the total discharge of nitrogen and phosphate from the conventional roof and the Green Roof was: Table 14 Green Roof reduction in Nitrogen and Phosphates Nitrogen mg /m 3 Phosphate mg/m 3 Conventional roof Green Roof 70 mg/m 3 75 mg/m 3 Reduction 74% 49% However, one of the greatest benefits of a Green Roof is its impact on visitors and users, in an accessible roof, which is referred as the amenity value.

195 16.6 Benefits of Green Roofs for amenity The use of flat roof space for recreation is not a new concept. Many schools dating from the Victorian era have playgrounds at roof level, although not all are in use anymore. In one case, North Haringey Primary School, such a playground has been transformed into a roof garden, planted with a variety of species to reflect the ethnic diversity of the school. Figure 12 North Haringey School amenity space on roof Source: Livingroofs.org Moorgate Crofts Business Centre is an excellent example of a multi-use Green Roof. The semi-extensive Green Roof reduces rainwater runoff, decreases enrgy requirement, and allows elevated views across the Don Valley from its conference rooms suplemented by the planting. It also provides a social amenity for staff and visitors to relax and unwind. Figure 13 Moorgate Crofts Business Centre, Rotherham Source: Rotherham Metropolitan Borough Council

196 The White Rose Office Park in Leeds is home for a range of Blue Chip corporate tenants. The developer, Munroe K, has been keen to create a very specific architectural and landscape style (see below). The style is simple, highly contemporary and stylised. Figure 14 White Rose Car Park Green Roof Source: Mitchell Harris Partnership The desire to include a series of grass roofs over underground car parking was initially based on practical and aesthetic ambitions; however this has yielded a recognised environmental benefit in the attenuation of water runoff from the site. This added benefit was clearly demonstrated during the recent heavy rains in South Yorkshire when examination of the water outfall points serving the grass roof identified a delayed and more controlled level of water run-off from the green roof areas. Another good example of how Green Roofs can make excellent amentity space is the planned St Vincents Park in Solly Street, Sheffield which is a commercial car park incorporating residential units and B1 offices with a rooftop public park. The Green Roof will be an intensive roof with substrate depths ranging from 280mm to 1100mm. It will be planted with wild flowers, bulbs, climbers, shrubs, hedging tree Planting and have extensive grass/lawns. It was the winner of the Green Roof Centre 2007 Innovation Award Figure 15 St. Vincent s Park artist impression Source: Coda Studios The site was designated by the St Vincents Action Plan for a park/public amentity/open space. Street level access and financial constraints meant it was viable to create a park on rooftop of the building. The Green Roof/park will improve the visual appearance and environmental performance of the building and more importantly provide a much needed amenity for local residents and visitors. It would be an interesting exercise to see how many users of the new park appreciate that St.Vincent s is infact a Green Roof?

197 Green space is recognised as being beneficial to health; reducing stress levels and providing escape from the stresses of urban living. This benefit is exploited by hospitals especially in Germany where such buildings commonly have Green Roofs. The increasing density of new developments where there is relatively little green space at ground level is becoming the norm in the capital. The provision of green space for amenity, both for public and private use, can be achieved through the provision of Green Roofs. It could be argued that the provision of Green Roofs may become a necessity, as there is a trend towards high quality and high-density inner city apartments for young professionals who may demand high quality green spaces within developments. Observations by Hutchinson (2003) on one Green Roof in Portland, Oregon noted a number of activities going on such as dog walking, clothes drying, cooking, eating and drinking, and even the setting off of fireworks. Golf course and football pitches have been implemented at roof level in other parts of the world Urban Heat Island Effect (UHIE) Urban areas have a higher average temperature than surrounding rural areas; this difference in temperatures is called the urban heat island effect (UHIE) and is caused by the reduction in green space through urbanisation and the large amount of hard surfaces that provide high thermal mass. Summers by 2050 will be C hotter... in central London the urban heat island currently adds 5-6 C to summer night time temperatures and will intensify in the future. London Climate Change Partnership. The dark surfaces of roofs exacerbate the UHIE by absorbing summer heat and reflecting it back to the atmosphere during the night. As the UHIE increases there is greater need for air conditioning and therefore energy, as buildings heat up. Furthermore increases in the UHIE effect can lead to increased levels of air pollution in cities particularity ozone, which combined with an increase in temperatures can exacerbate health problems, especially in the old, young and vulnerable. As a quick fix solution to avoid thermal gain into the buildings many roofs are now white roofs which is either the natural colour of the surface of the waterproofing or it has a painted surface. However, a white roof reflects 70% of the energy back into the atmosphere increasing the UIHE On the other hand the Green Roof effect of evaporation and transpiration acts to cool air. Furthermore by providing a cooler surface at roof level the Green Roof reduces the need for air-conditioning and the emission of waste heat into the atmosphere. The combined effect is to reduce the UHIE. A modelling exercise undertaken in New York by the New York Heat Island Initiative determined that providing 50% Green Roof cover within the metropolitan area would lead to an average C reduction in surface temperatures. It noted that for every degree reduction in the UHIE roughly 495 million KWh of energy would be saved. There is no reason to doubt that comparable relative reductions could be achieved in the UK. Reducing the UHIE in a metropolitan area is a virtuous circle in that a global reduction in temperature means less energy used by buildings which means less heat released to atmosphere and the UHIE will reduce even further. A number of research projects have concluded that Green Roofs are the single most effective weapon against the Urban Heat Island Effect.

198 17. Case Studies We have seen that there are easy costs/ benefits to establish and there are other costs and benefits that are very difficult because they depend on the ability of the design team to maximise them. In the following case studies we demonstrate how to use NPV to determine whether a Green Roof is an economic option. We are only considering the direct benefits of extended roof life and energy reduction in these case studies as they are the easiest to identify. In the case of Barclay s Tower the roof is inaccessible and will therefore have limited effect on value from an amenity perspective and the saving in energy has limited impact due to the size of the building. When considering this approach for any new building the extent of delivering the other benefits will depend on the design, location, the professional team and the determination of the client Barclays Tower Canary Wharf Barclays Tower is a 1million sqft (92,750 m 2) office block with 34 floors. The Green Roof is at 140m above street level. The extensive roof was installed in 2005 and used light substrates planted with drought and wind tolerant plants. The substrate is locally sourced recycled crushed brick and concrete (from Charlton, SE London, less than 5 miles travel). This substrate has had a small amount of soil, pine bark and shingle added to it and has been seeded with a wildflower mix. On the surface of crushed brick and concrete there are circles of large pebbles. These provide bare areas for rare insects that like dry exposed sites. Figure 16 Sedum mat area of the roof Barclay s Tower The roof was partially planted with a sedum mat to provide resistance to soil erosion due to the wind on the exposed site. The use of the wildflower mix in the substrate meant that as the roof matured a wide range of plants developed avoiding the monoculture of sedum mats. Since the building was occupied in 2002 there are 3 years of pre and 2 years post Green Roof energy data. In the financial appraisal the energy savings have been averaged.

199 Table 15 The Canary Wharf data The size of the roof 850m 2 Energy costs 0.17 /kwh Life 30 years Discount rate 7% Green Roof life 30 years Non-Green Roof life 25 years Maintenance The same for both roofs kwh to CO2 conversion factor 0.43kg CO 2 Table 16 Barclay s Tower Financial Appraisal The results of the financial analysis are: NPV Capital Cost Energy kwh/pa CO 2 t/pa Non-Green Roof (55,364) 46, Green Roof (3,402) 63,750 29, Table 16 shows that a Green Roof costs 17,000 more to install than an exposed roof. However, an NPV calculation provides the real value of the longer life and annual energy savings provided by the Green Roof at 58,766 more than the exposed roof. Equally over 30 years the Green Roof will save approximately 390 tonnes of CO2 from being emitted to the atmosphere Paradise Park Children s Centre: The building was built with a brown roof over the habitable area. This has provided a small increase in the thermal insulation properties of the roof. Of greater benefit than reducing heat loss, however, is the increased thermal inertia of the roof due to its mass. This thermal mass delays the flow of heat into the building when there is a heat gain due to a high sun altitude. The depth of the brown roof is approximately 150mm and its thermal mass slows the transfer of heat through the roof by about 1 hour for every 25mm of dense material. Therefore with a depth of 150mm of high mass material the solar gain through the roof during the summer is slowed by up to 6 hours. The highest gain through an exposed flat roof, in the summer, is at noon, the maximum flow of heat through this roof is therefore delayed until early evening. As the building normally closes at 5pm the occupants no longer will be overheated in the building, so obviating the need for air-conditioning. Richard Pearce Building Services Engineer says: The heat gain for the building is approx 28kW and the electrical energy that would be used during the period of heat gain would be about 9.4kW per hour. If air-conditioning was used over a summer period the approximate energy use would be 3,800kW/hrs, the equivalent of about 1.6 CO2 e tonnes per annum.

200 Table 17 Paradise Park Data The size of the roof 400m 2 Energy costs 0.17 /kwh Life 30 years Discount rate 7% Green Roof life 30 years Non Green Roof life 25 years Maintenance The same for both roofs kwh to CO 2 conversion factor 0.43kg CO 2 Table 18 Paradise Financial Appraisal The results of the financial analysis are: NPV Capital Cost Energy kwh/pa CO 2 t/pa Non-Green Roof (26,053) 22, Green Roof (18,200) 34,000 1, Table 18 shows that a Green Roof costs 12,000 more to install than an exposed roof. However the NPV shows that the benefit of the Green Roof with its longer life and the energy savings each year, over the full 30 years, is 7,853 less than the exposed Equally over 30 years the Green Roof will save approximately 15.6 tonnes of CO 2 from being emitted to the atmosphere. In these case studies we see how with just two benefits, most Green Roofs will pay for themselves. However, there are a number of barriers that might be raised before a successful Green Roof can be completed.

201 18. Barriers to Green Roof implementation A report by the Ecology Centre to the GLA on implementing Green Roofs within the London Plan concisely identifies a number of perceived barriers to implementation of Green Roofs. The report uses a survey by Ingleby in 2002 of architects, ecologists, local planners and engineers in London which identified a number of concerns regarding Green Roofs. It is clear that these concerns arise because Green Roofs are a relatively new technology for the mainstream UK construction industry and they are unaware of experience in other countries. The main concerns the Ecology Centre cite are: Lack of common standard Fire Hazard Maintenance Cost Structural issues Leakage and damage to waterproofing Lack of expertise Lack of policy Each of these barriers will be looked at in detail below Lack of common standard The lack of a British Standard is often cited as a real barrier to whole-scale uptake of Green Roofs. The major UK suppliers of engineered Green Roofs are fully signed up members of the German FLL the Landscape Research, Development & Construction Society. This body provides standards for landscaping in Germany, whilst standards used in Switzerland, Austria, Hungary and Italy, are variations on the FLL. Japanese and North American standards are also based on the FLL. The FLL covers all aspects of Green Roofs from waterproofing, soils, vegetation, treatment on intensive Green Roofs [tree planters etc], balconies, installation methods and procedures, and maintenance. The guidance stipulates DIN standards for specific areas of greening. The FLL accept that their standards are viewed by some to be over rigorous [pers. comm. Gedge 2004]. Therefore the lack of standards in the UK is only likely to be an issue where a supplier is either not an affiliate of or does not work to FLL standards. Over the last 2 years a number of the largest Green Roof suppliers in Germany and Switzerland have set up partnerships with UK waterproofing companies and the majority of these abide by or are affiliates to the FLL. The largest companies supplying Green Roofs in the UK have been in operation for much longer than this and are recognised as leading Green Roof suppliers both in the UK and Germany.

202 18.2 Fire hazard Although there is a perception that dry vegetation during the summer months could lead to fires being started on Green Roofs, the FLL standards also have strict guidelines on this issue. These include high levels of fire resistance and fire proofing for membranes and other layers beneath the soils and vegetation. Furthermore there are strict guidelines regarding the use of firebreaks and the amount of combustible material permitted in Green Roof soils. Extensive roofs are only considered to be fire resistant if the substrate/soil is at least 30mm deep the substrate/soil contains less than 2% organic matter there is a 1m wide gravel or slab fire break every 40m gravel/shingle strips are provided around all structures penetrating the roof covering. These gravel/shingle strips should be at least mm in width, or 1m in width where they are to act as firebreaks on large roof areas. In contrast to the UK rather than considering a Green Roof a fire hazard, in Germany they are considered to provide a protective barrier preventing the waterproofing elements from catching fire. For this reason it is possible for building owners to get a reduction of 10 to 20% on fire insurance in Germany when a Green Roof is installed. Considering the millions of square metres of Green Roofs that have been installed in Germany and Switzerland over the last 25 years, to these standards, it is clear that fire hazard should not be viewed as a real barrier to uptake in the UK Maintenance Maintenance of a Green Roof will depend on the roof system and what is desired from it. Intensive and semi-extensive Green Roofs are in many ways a high rise version of a garden, and therefore will require similar level of maintenance. This will include weeding, mowing, hedge trimming, fertilising and irrigating. It is often stated that even semi-extensive wildflower meadows need an annual mow to maintain floristic diversity. However, it is possible for this to be a neglected aspect and there are a number of instances in London where such management has not been undertaken. This lack of maintenance has had no impact on the building, but merely reduced the value of the meadows from an ecological point of view. Extensive Green Roofs, which also may not be amenity spaces, need very low maintenance. A 1-2 year inspection will normally suffice to weed out unwanted plants, remove deep roots and, if necessary provide fertilisation. For the first year such work is generally covered by the installation team, after which it becomes the responsibility of the building owner or the building management team. It is generally accepted in the roofing industry that annual maintenance on Extensive Green Roofs and exposed roofs is now the same in terms of days and cost Contrary to a common perception the use of a Green Roof can have a positive impact on maintenance in that intentional vegetation within the system keeps out unwanted vegetation that can harm the integrity of the building s fabric. On grey roofs and other conventional roof systems buddleia (butterfly-bush) and other shrubs can become established and potentially cause problems. The presence of a root barrier and competition from other plants can limit this significantly. In fact even a plain roof needs maintenance and the facilities manager for Barclays Tower in Canary wharf says that his sedum mat roof needs less maintenance than the exposed sections of roof.

203 18.4 Cost The cost of a Green Roof will vary depending on the system used. It will also depend on the height of the building, number of intrusions, size and type of system, depth of insulation required and many other factors. Intensive Green Roofs can vary in cost depending on the amount of vegetation cover and the type of vegetation. Figure 17 Jubilee Park Canary Wharf London Source: Living Roofs and Walls Report, Ecology Consultancy Ltd, EPG Clear and Savills Hepher Dixon An indicative cost is 140/m 2 inclusive of waterproofing and insulation. The use of large trees, furniture, planters and irrigation will increase costs - for example, a planting scheme of this nature at Jubilee Park in Canary Wharf that included trees, fountains, irrigation system etc. resulted in costs as high as 453/m 2 (pers. comm. Anthony Partington). However, these costs may be balanced to a certain extent by increased building value. An indicative cost for a semi-extensive Green Roof is in the region of /m 2, but again could be more depending on the types of plants used, water features and furniture. An indicative cost for an extensive Green Roof will depend on the type of system used. The cost will also vary depending on whether it is a warm or cold roof. Table 5 outlines some indicative figures for Green Roofs, including waterproofing and insulation. Warm roofs may be restricted to a sedum blanket with a thin substrate layer unless there is greater structural loading, and the cost of a Green Roof on a warm roof is always going to be higher than the normal cost of the roof. However, when an inverted roof system is used the structural capacity to hold a Green Roof substrate-based system is already present as an inverted roof needs ballast, which conventionally is shingle or paving. Furthermore a substrate based roof can result in other cost savings due to the reduction in the number of drainage outlets and in the amount of storm water amelioration at ground level. Further cost savings can be factored in when the reduced energy needs within the building are also taken into account. In Germany, for similar reasons, it is recognised that a Green Roof is the most cost-effective method of roofing over a 25 year period. A recent study in Birmingham Eastside by Hyder Consulting estimated that a single plot with Green Roofs could realise a saving of 100,000 through a reduction in surface water amelioration costs. The study then considered the cost of increased structural requirements for the buildings in question to hold a substrate based Green Roof; these were considered conservative at 53,000.

204 The cost saving to the plot through the use of a Green Roof to reduce on site storm water storage and other drainage costs was around 47,000 which is the same as installing 3,000m 2 of Biodiverse Green Roof. The current vogue when discussing Green Roofs is to try and relate the additional capital cost to a % of the total build cost. This is derived from the current desire to reduce all cost projections to a simple % addition. This is not only irrelevant it also does not identify the real cost benefit outcomes. The problem with Green Roofs is that they do not fall within any expertise of the existing design team and they therefore look for simple solutions rather than extending the expertise available to the team Structural issues The usual reason given for objecting to a Green Roof is the perception that the cost of additional structure required to carry the increased load outweighed any financial benefit. This was tested by a study carried out in London, by Livingroofs.org, which revealed that 92% of developers perceived that the physical structure of many buildings prevents the establishment of Green Roofs, compared to only 27% of Structural Engineers. The current requirement to provide thermal mass, in order to apply with Part L of the current Building Regulations, is leading designers away from thin lightweight roofs and back to structures that will accommodate Green Roofs with little or no increased strengthening. Below are the loadings of the various roof coverings available. They exclude those for an exposed standard warm roof i.e. without any additional roof treatment: Table 19 Green Roof additional loadings Roof type Loading lower (kg/m2) Loading upper (kg/m2) Gravel Surface Paving slabs Vehicle Surface Extensive Green Roof sedum mat Extensive Green Roof substrate based Intensive Green Roof NOTE: loads are fully saturated. Structural issues are linked to cost as outlined above. In the case of an inverted substrate based Green Roof there should be relatively limited or zero need for extra structural load. Hyder Consulting in the drainage policy report for Birmingham Eastside state, Even on single ply roof constructions where ballast is not normally required, the increase in load is unlikely to exceed 20%. Due to the constraints placed on designers by British Standards and Codes of Practice, it is possible that an increase in load of this magnitude could be accommodated without modification of the structural sizes. There can be issues regarding Green Roofs and structural loads on lightweight industrial buildings that can lead to increased costs. However, savings in the need for storm water amelioration tanks could well balance out the extra cost for a Green Roof.

205 18.6 Damage to Waterproofing Concerns are often expressed that Green Roofs will leak. Historically flat roofs are perceived as more vulnerable to leakage due to the effects of the climate (UV, frost and ponding) on waterproofing systems. Most established Green Roof suppliers provide FLL rated root barriers, which protect water-proofing membranes from the potential negative impact of roots. Furthermore established companies will leak test before the implementation of the Green Roof element. Contrary to perceived wisdom in the UK, in Germany it is accepted that a Green Roof adds value to the waterproofing by protecting membranes from the effects of climatic factors. In general a Green Roof can extend the life of a membrane by a factor of two if not longer (this is dependent on quality of waterproofing, installation and Green Roof system). However, extended warranties and guaranties are not offered in the UK Lack of Expertise Roof gardens and terraces are not new. In London there are several well known examples: the Queen Elizabeth Hall has a series of roof gardens, the world famous roof garden at Barkers of Kensington was installed in the 1930s, No. 1 Poultry, home of Conran s Coq d Argent restaurant, has a lawn at roof level. A short walk around central London reveals that roof gardens are more common than may be first realised. The large scale use of extensive and semi-extensive Green Roofs though is relatively new especially at a commercial level. A number of projects were completed in the late 1980s and early 1990s, but the use of Green Roofs in new developments has only been really considered in the last 5-10 years. During this time, roofing companies in the UK have gained a track record of delivering Green Roofs, although there continues to be a lack of understanding and expertise of the full range and performance of Green Roof systems outside of the roofing industry. However, the overall perception that there is a lack of expertise in the UK regarding the provision and implementation of Green Roofs is not really true if the design team take the time and effort to find specialist assistance. Now that the design of the Natural Green Roof is more widely understood, and sites such as and provide standard designs and details, the installation has moved away from specialist suppliers, such as the roofing supplier, to general contractors and groundworkers. This opens up the industry to competition which will invariably reduce costs.

206 18.8 Lack of Policy There is no central Government guidance and therefore we lack consistent local policies across the UK. Other cities around the world have adopted a number of measures to promote Green Roof Basel Beijing Berlin Chicago Cologne Linz Munster Portland, Oregon Seattle Tokyo Toronto Vancouver Building Regulations Policy Targets Financial Incentives and Mandatory Policy Requirements Building Regulations and Financial Incentives Financial Incentives Planning Policy and Financial Incentives Financial Incentives Financial Incentives Mandatory Policy Requirements Planning Policy and Financial Incentives Financial Incentives Planning Policy and Building Bylaws In summary the principal means by which the fifteen cities surveyed encourage or require Green Roof developments can be summarised as follows: i) Direct Financial Incentives - Grants and subsidies; ii) Indirect Financial Incentives - Reduced drainage charges or larger development allowances; iii) Ecological Compensation - The green factor approach; iv) Building Regulations and Planning Policy. In addition, many of the cities are sponsoring demonstration projects and the provision of information to developers.

207 Conclusion This report has served to reinforce the long accepted environmental benefits of Green Roofs. However, poorly constructed financial arguments focusing on capital cost often cause developers to drop Green Roofs on cost grounds. In response, this report clearly demonstrates that by using standard financial appraisal techniques such as Primarily Net Present Value (NPV) and Internal Rate of Return (IRR), and by including the cost in use as well as capital cost, the medium financial benefits significantly outweigh the initial cost considerations. Green Roofs of all types provide a positive Net Present Value to both the developer and the occupier which means they are better off with a Green Roof than without one. When using the Whole Life Cost approach, the authors have not found a single example of an exposed roof being more cost effective than a Green Roof. Further, we have shown that Green Roofs have a positive effect on the development yield of around 0.5%. This relatively small percentage improvement goes straight to the developer s bottom line and has a significant impact on the profitability of the project. This argument alone is enough to ensure that Green Roofs become the common option for roofs on all types of developments. This report emphasises that the maximum benefit is achieved through Green Roofs that are accessible to building occupiers. The adoption of Green Roofs is not a surprise as any technology that: Reduces letting voids Increases letability Protects and improves the environment Delivers cost saving to the building occupier Reduces CO 2 emissions Reduces surface water off site requirements Reduces the size and complexity of the on site drainage system Provides a positive social impact on staff Improves staff productivity Reduces energy consumption in the building Improves the performance of solar production of energy Reduces the overall Urban Heat Island effect Provides positive local PR Receives positive support from the local planners will increase the value of the development! What other environmental improvement can be added to a building with so many benefits?

208 Useful sources of information If you consider adding a Green Roof to your next development, guidance and advice is available from: The Green Roof Centre, Sheffield University. Living Roofs, the independent UK website to promote Green Roofs. Building GREENer - Guidance on the use of green roofs, green walls and complementary features on buildings (CIRIA, July 2007) For more information from The Solution Organisation: info@thesolutionorganisation.com Web

209 References Acks 2003, A framework for cost-benefit analysis of green roofs: initial estimates, pers.comm. Akbari and Konopacki, 2004; Energy effects of heat-island reduction strategies in Toronto, Canada. Energy. 29, (LBL Study) Akbari etal, 2001, Cool surfaces and shade trees to reduce energy use and improve air quality in urban areas. Solar Energy, 70, 3, Banting Dr D et al, Oct 2005, Report on the Environmental Benefits and Costs of Green Roof Technology for the City of Toronto, Dept. of Architectural Science, Ryerson University. CIRIA, 2000, Sustainable urban drainage systems: design manual for England and Wales. Report C522 London: CIRIA. CIRIA, 2004, Sustainable drainage systems: hydraulic, structural and water quality advice. Report C609 London: CIRIA. England E et al, 2005, Vegetated Roofing Technology: An Evaluation. Gregg A, Parker T and Swenson R, A Real World Examination of PV System Design and Performance United Solar Ovonic LLC, Auburn Hills, Michigan 48326, and SolarQuest Santa Cruz, CA 95061, Analysis/PVSC2005.pdf (cited June 2007). Ingleby A, 2002, Green Roofs a study of their benefits, and barriers to their installation in London. Kolb W, 2005, Good reasons for roof planting - green roofs and rainwater, 2005 International Conference on Urban Horticulture. Liu, K, 2002, Energy Efficiency of and Environmental Benefits of a roof top garden. National Research Council Canada Onmura et al, 2001, Study on evaporative cooling effect of roof lawn gardens, Energy and Building 33, Sonne, J K, 2006, Energy Performance Aspects of a Florida Green Roof, Florida Solar Energy Center (FSEC). Wong, N. H, Tay S. F, Wong, R, Ong, C. L, Sia, A, 2003, Life cycle cost analysis of rooftop gardens in Singapore, Building and Environment 38, 499. Wong, N.H., Cheong, D.K.W., Yan, H., Soh, J., Ong, C.L., Sia, A., The effects of rooftop gardens on energy consumption of a commercial building in Singapore. Energy and Buildings. 35, London Climate Change Partnership, 2005, London s Warming. The Impacts of Climate Change on London (cited 19 May 2007) Hyder Consulting - Green Roofs for Eastside Outline Drainage Policy 2006.

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211 Green Roof Developor s Guide This document was funded by Life+ and Groundwork Sheffield, in partnership with the Green Roof Centre. Published by Groundwork Sheffield September 2011

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213 Published by Groundwork Sheffield

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215 Appendix U NFRC Awards press release 215

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219 Appendix V GRO meeting agenda 219

220 Appendix W Agenda for GRO meetings 2ns April pm Agenda will be: 1. GRO Status, Structure and Plan - Mark Harris 2. Funding proposal - Mark Harris 3. Meeting dates for 2012/13 - Mark Harris 4. NVQ/Lantra training - Nick Ridout 5. Fire testing - Warrington/University of Ulster - Phil Jarratt (by proxy) 6. Drainage and Thermal desktop research projects - Jeff Sorrill 7. Development of existing GRO Code of Best Practice - Mark Harris 8. Website development thoughts - Mark Harris 9. Announcements to members & potential members - Mark Harris 220

221 Appendix W Attendees to GRO event 221

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223 Appendix X Glossary of terms 223

224 Appendix Y Glossary of terms BALI - British Association of Landscape Industries - A trade body for the landscape industry. Biodiversity - The variety of life on earth. This means species, genetic variations within species, and the communities, habitats and ecosystems within which they occur. BREEAM - Environmental Assessment Method for Buildings Around The World. Brown roof - A green roof where the vegetation is intended to replicate brownfield habitat. It can be seeded or self colonized. Conservation - A series of measures required to maintain or restore natural habitats and populations of species of wild fauna and flora. Defra - Department for Environment, Food and Rural Affairs - The UK Government department tasked with issues such as the environment, rural development and the countryside. EA - Environment Agency -A UK government agency concerned mainly with rivers, flooding, and pollution. Extensive green roof - A roof with thin soil, and little or no irrigation, which creates stressful ie low water retention and nutrient poor, conditions for plants. GRC - The Green Roof Centre - An independent research and demonstration hub, which supports and promotes the uptake of green roofs. Green roof - A green roof is one with plants intentionally growing on its surface. The vegetated surface provides a degree of retention, attenuation and treatment of rainwater, and promotes evapotranspiration (depending on construction details, also known as an eco roof, roof garden, living roof or brown/ rubble roof). GRO - Green Roof Organisation - an independent body representing the industry. GWS - Groundwork Sheffield a charitable organisation formed in 2004 as part of a national federation of Groundwork Trusts. HCA - Homes and Communities Agency - The National Housing and Regeneration Agency REY - Resource Efficiency Yorkshire An organisation formed to help businesses in Yorkshire and Humber to prosper in the new Low Carbon Economy. RIBA - Royal Institute of British Architects - Professional association of architects in the United Kingdom along with international members. SUDS - Sustainable drainage systems or sustainable (urban) drainage systems. A sequence of management practices and control structures designed to drain surface water in a more sustainable fashion than some conventional techniques (may also be referred to as SUDS). Task Group - Meetings held between GWS and the University of Sheffield Workshops - Consultation with wider stakeholders. Minimum of 3 hours 224

225 Appendix Y GRO specialist groups 225

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227 Appendix Z Code presentation 227

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