Townsville Residential Energy Demand Program (TRED Program)

Transcription

1 CitySolar Community Capacity Building Program Townsville Residential Energy Demand Program (TRED Program) Investigation into Existing Local Government Roof Coating Performance Inclusions in Planning and Development Processes Investigation Report Version: Final Issue

2 Acknowledgements This document has been developed through funding from the Australian Government Solar Cities Program and the Townsville City Council (Townsville Queensland Solar City). The document has been developed by researchers from Griffith University (members of the The Natural Edge Project (TNEP), a non-profit sustainable development research and education think-tank, hosted by the Griffith University Urban Research Program) under the supervision of Associate Professor Jago Dodson and Dr Stephen Horton. The research team included Karlson Charlie Hargroves, Cheryl Desha, Angie Reeve, and David Sparks. Research was carried out under the direction of, and in collaboration with, Greg Bruce and the team from Townsville City Council Integrated Sustainability Services, including Mark Robinson, and Dylan Furnell, and was advised by Ian Cruikshank, Manager Solar City, Energy Sustainability and Market Development, Ergon Energy. Disclaimer While reasonable efforts have been made to ensure that the contents of this publication are factually correct, the parties involved in the development of this document do not accept responsibility for the accuracy or completeness of the contents. Information, recommendations and opinions expressed herein are not intended to address the specific circumstances of any particular individual or entity and should not be relied upon for personal, legal, financial or other decisions. The user must make their own assessment of the suitability of the information or material contained herein for their use. To the extent permitted by law, the parties involved in the development of this document exclude all liability to any other party for expenses, losses, damages and costs (whether losses were foreseen, foreseeable, known or otherwise) arising directly or indirectly from using this document. This document is produced for general information only and does not represent a statement of the policy of the Commonwealth of Australia, Ergon Energy, or the Townsville City Council. The Commonwealth of Australia, Townsville City Council, Ergon Energy and all persons acting to prepare this report accept no liability for the accuracy of or inferences from the material contained in this publication, or for any action as a result of any person s or group s interpretations, deductions, conclusions or actions in relying on this material. Citation Townsville City Council (2012) Investigation into Existing Local Government Roof Coating Performance Inclusions in Planning and Development Processes: Investigation Report, Townsville City Council and Griffith University (The Natural Edge Project), as part of the Australian Government Solar Cities Program. Any enquiries about this document should be directed to: Mr Mark Robinson Carbon Cycle Team Leader Integrated Sustainability Services Townsville City Council mark.robinson@townsville.qld.gov.au Page 2 of 29

3 Table of Contents 1. Introduction... 4 Roof coating performance requirements... 4 Cool Roofs... 4 Current Drivers Roof Performance Codes and Standards... 7 Building Code of Australia... 7 Australian Standards... 8 BASIX Building Sustainability Index State Government Development and Planning Policies Queensland Other State Governments Local Government Development and Planning Policies Queensland Local Governments Other Australian Local Governments International trends International Code Council New Zealand European Union United States of America Summary Page 3 of 29

4 1. Introduction Roof coating performance requirements This report investigates components of government planning schemes and policies that require new urban developments to include minimum roof coating performance measures. It also describes the coverage of roof coating performance (cool roofs) in development requirements nationally and internationally in ways that could similarly be included into Townsville City Council s planning scheme. Regulatory requirements and standards often specify both mandatory and prescriptive requirements for buildings. Mandatory requirements specify compulsory standards that apply to all buildings for example correct installation requirements for insulation. Prescriptive requirements specify compulsory standards that relate to a component or group of components for example the thermal resistance properties of ceiling insulation. 1 This report outlines several policy options for encouraging or requiring cool roofs in Townsville, as well as key factors that will need to be considered in the planning and implementation of such policies. A review of cool roof policies from around the world suggests that there are a number of ways in which the installation of cool roofs can be encouraged. Further, this review provides guidance for elements that policies could include, and some potential areas of risk that must be considered. One major finding is that this is still an emerging area in Australia, and while many cities are considering whether to encourage the use of cool roofs, none appear to have done so to-date. Cool Roofs Cool roofs decrease the flow of heat into a building in two ways - firstly by reflecting a larger proportion of the solar radiation that strikes the roof, and secondly by quickly re-radiating any heat that is absorbed. These two ways of reducing heat transfer are respectively called solar reflectance and thermal emissivity (see figure 1), and are enhanced in cool roofs through the use of specialised paints and paint additives. Both of these characteristics are important and contribute to effective cool roof performance. It is important to note that reflectance is a measure of total solar energy, including the non-visible portions of the spectrum. 2 Only the visible portion of the spectrum, however, contributes to glare. Light surfaces tend to be reflective in the nearinfrared portion of the spectrum. 3 1 Ibid 2 Busselton Shire Council (2010) Reflective Building Materials: Officer s Report, Draft, Busselton Shire Council. 3 Bretz, S., Akbari, H., and Rosenfeld, A. (1998) Practical Issues for Using Solar-Reflective Materials to Mitigate Urban Heat Islands, in Atmospheric Environment, vol. 32, no. 1, pp Available online: Page 4 of 29

5 Figure 1: Solar reflectance and thermal emittance are important properties of cool roofs Source: Cool Roof Rating Council, Cool roofs provide the most benefits when the ambient temperature rises above 24 C. 4 Below this temperature, a normal roof does not tend to receive enough incoming solar radiation to impact significantly on house temperatures. The tropical climate in Townsville, with its high incidence of solar radiation and high year-round temperatures, is therefore particularly well suited to cool roofs. Current Drivers There are a number of factors driving the uptake of cool roofs. Primary Drivers: Sustainability As people become more aware of sustainability issues there has been a movement towards passive design principles that may help to reduce energy consumption. Cool roofs help to reduce internal temperatures, providing a high level of thermal comfort without the need for mechanical cooling. Passive design principles The adoption of passive design principles is increasing in response to sustainability awareness and industry trends. A cool roof can provide a more comfortable internal environment, particularly in hot climates, due to the reduced solar heat gain. Energy costs Energy costs are increasing around Australia and air conditioning is responsible for a large portion of energy demand. Cool roofs can help reduce energy costs by improving internal thermal comfort condition and thereby reducing the desire for mechanical cooling. Changes to energy tariffs The introduction of new tariff structures aimed at discouraging energy use during peak periods will encourage innovative ways to reduce peak demand. Cool roofs help reduce the desire for air-conditioning and in doing so help to avoid electricity use during peak periods. 4 Suehrcke, H., Peterson, E., and Selby, N (2008) Effect of roof solar reflectance on the building heat gain in a hot climate, Energy and Buildings, vol 40, pp Page 5 of 29

6 Carbon tax the introduction of the carbon tax will impact on energy prices, creating further incentive to reduce energy demand. Pressure on energy infrastructure in many regions throughout Australia energy infrastructure is approaching capacity, necessitating massive investment in new supply infrastructure if demand cannot be appropriately managed. Cool roofs can help reduce the use of mechanical air-conditioning, which contributes to peak energy demand.. Energy utilities and state governments have shown a strong interest in reducing peak demand, which has a large impact on energy infrastructure spending. Secondary Drivers: Roof longevity Roofs are subjected to extreme temperature changes throughout the day, putting roof materials under stress. Dark-coloured roofs can reach temperatures up to 50 C above ambient temperatures. However, studies have shown that light-coloured roofs can stay C cooler than dark-coloured roofs. Because cool roofs stay cooler, they are subject to less diurnal thermal expansion and contraction and may consequently have a longer service life. Efficiency of roof-mounted photovoltaic systems Photovoltaic panels operate more efficiently at lower temperatures. Panels mounted on a dark roof will become considerably hotter than those mounted on a light roof decreasing their efficiency. A cool roof can help reduce roof temperatures and this may help improve photovoltaic panel efficiency. Efficiency of ducted air-conditioning - A cool roof has the potential to greatly improve the efficiency of ducted air-conditioning. A dark roof will cause the roof cavity to heat up: - the equivalent of running ducts through an oven. Cool roofs reduce heat in the roof space, thereby reducing heat transfer to air ducts and distribution systems and lowering their overall energy use. Urban Heat Island Effect Urbanised areas are generally warmer than surrounding rural areas due in part to the prevalence of dark surfaces. This is known as the urban heat island effect and causes average daytime air temperatures in cities to be up to 2 5 ºC higher than surrounding rural areas. Research is showing that the lower surface temperatures of cool roofs may reduce a building s contribution to the urban heat island effect, making urban environments more comfortable places to live. Page 6 of 29

7 2. Roof Performance Codes and Standards Roof performance may be governed by various codes and standards. The following section details the relevant codes and standards that may relate to cool roofs and roof performance requirements. Building Code of Australia The Building Code of Australia in the National Construction Code series is the national technical document that sets the standards of building work in Australia. Individual States and Territories have variations that set out certain requirements unique to that State or Territory. The Building Code of Australia recognises the heat reduction benefits of low solar-absorptance (high reflectivity) coatings and classifies roof and wall materials according to solar absorptance values. The BCA requires the combined thermal performance of a roof and ceiling to meet certain thresholds. A roof or wall with low solar absorptance therefore requires less insulation under the BCA. This applies only to residential buildings rather than commercial or institutional buildings. Consequently there is little incentive for the use of cool roofs for these structures at present. Energy Efficiency requirements stipulate that a building must have, to the degree necessary, an appropriate level of thermal performance to facilitate the efficient use of energy for artificial heating and cooling. In order to verify this, it is required to consider solar absorptance of external surfaces. Subject to (e), a roof must achieve the Total R-Value specified in Table 1 below for the direction of heat flow. 5 Table 1: Roof and Ceiling - Minimum Total R-Value Climate Zone Direction of heat flow 1 Altitude < 300m Downwards 2 Altitude > 300m Downwards and upwards 3 4 & 5 6 & 7 8 Upwards Minimum Total R-Value for a roof with an upper surface solar absorptance value of not more than 0.4 Minimum Total R-Value for a roof with an upper surface solar absorptance value of more than but not more than 0.6 Minimum Total R-Value for a roof or ceiling with a roof upper surface solar absorptance value of more than Note: Altitude means the height above the Australian Height Datum at the location where the building is to be constructed. Source: Australian Building Codes Board (2011) 5 Australian Building Codes Board (2011) National Construction Code: PART Building Fabric, National Construction Code, Australia Page 7 of 29

8 Cool roofs are thus recognised in the Building Code of Australia, however the BCA does not currently prescribe any minimum requirements relating to roof solar absorptance or thermal emissivity. Australian Standards The Australian/New Zealand standard on thermal insulation AS :2002 (Appendix G) notes that external sunlit surfaces with low solar absorptance (high reflectance) stay cooler and help to reduce heat flow. 6 At present there are no additional Australian Standards that apply specifically to cool roofs. BASIX Building Sustainability Index Credit systems are an alternative compliance measure, where a building must meet certain overall efficiency targets. This involves stipulating credit values for specific energy efficiency components, and allowing a dwelling to meet targets using whichever combination of components is appropriate for the particular structure and location. Credits may allow more flexibility in the way in which energy efficiency goals are achieved and may reduce the upfront cost of the building. An example of this type of system is the BASIX Building Sustainability Index developed by the NSW Government. The Building Sustainability Index (BASIX) is a web-based planning tool for councils and developers to assess the potential environmental performance of developments. It requires that buildings meet certain targets through the inclusion of energy efficiency measures in the design of residential dwellings A construction certificate or complying development certificate is then issued, outlining the commitments in the BASIX Certificate submitted with the application. These efficiency measures then become part of the development consent and the applicant is bound to comply with the commitments. Councils check development applications against BASIX certificates to ensure compliance. BASIX is flexible and easy to use and thus likely to be accepted by developers and councils. 7 Roof colour is included as an element in the BASIX certification scheme. 8 Roofs are classified as light, medium or dark as outlined in the following table. Roof insulation is required under BASIX for dark-coloured or medium-coloured roofs. Colour Solar Absorptance Light colour < Medium colour Dark colour > 0.7 BASIX is less stringent about cut-off values for solar absorptance than the Building Code of Australia, however the range of generally accepted values is still stipulated. This practice has led to an increase in the number of manufacturers supplying solar absorptance values for their 6 AS :2002, Materials for the Thermal Insulation of Buildings General Criteria and Technical Provisions, Standards Australia, Sydney. 7 BASIX (n.d.) About BASIX, Government of New South Wales, Australia, online: accessed 4 April Bluescope Steel (2011) National Energy Savings Initiative Issues Paper, Submission to Department of Climate Change and Energy Efficiency National Energy Savings Initiative, online: Page 8 of 29

9 products. For example, Figure 1 provides Bluescope Steel Classifications of COLORBOND steel Colours for BCA and BASIX for COLORBOND steel Standard 20 Colours. 9 Figure 1: BASIX and BCA Classification of Bluescope Steel products as light, medium, and dark Bluescope Steel (n.d.) Classification of COLORBOND steel Colours for BCA and BASIX, online: 10 Bluescope Steel (n.d.) Classification of COLORBOND steel Colours for BCA and BASIX, online: Page 9 of 29

10 3. State Government Development and Planning Policies Queensland The Queensland Development Code covers matters outside the scope of, and in addition to, the National Construction Code of Australia. The Queensland Government have amended the Building Act 1975 to limit or prohibit restraints that conflict the initiatives of the Sustainable Housing Act. Some of these amendments relate to roof colour, and more specifically the solar absorbance. Under section 246O, it removes restraints for the installation of a roof with a solar absorbance value less than Although there is no specific mention of the term cool roof within the Act, it identifies the need for high reflectivity roofs as an energy efficient design measure. Other State Governments South Australia Commercial and Institutional Buildings The South Australian Government is currently investigating the addition of cool roof requirements for commercial buildings (Class 5 through 9) in the State s Development Regulations. 12 A discussion paper has been released for comment, however there has as yet been no official changes to South Australian Development Regulations. The option being investigated is the mandated requirement for an upper surface solar absorptance value of not more than 0.4 for all flat roofs on air-conditioned commercial buildings (Class 5 through 9) in BCA Climate Zones 4 and 5. It is proposed that these cool roofs regulations would apply to both new and refurbished commercial buildings under a BCAapplicable development approval. Under the BCA, this would apply to the following building types: Class 5 office buildings used for professional or commercial purposes; Class 6 shops or other buildings used for the sale of goods by retail or supply of services direct to the public; Class 7 A building which is a car park or for storage, or display, of goods or produce for sale by wholesale; Class 8 A laboratory, or a building in which a handicraft or process for the production, assembling, altering, repairing, packing, finishing, or cleaning of goods or produce is carried on for trade, sale or gain; and Class 9 A building of a public nature, including health care buildings and an assembly building in a primary or secondary school. Subject to approval, the proposed changes would be first introduced into the South Australian Development Regulations 2008, and later introduced as a State variation to the Building Code of Australia. 11 Government of Queensland (2012), Building Act 1975, Australia, Reprint 8A. 12 Government of South Australia (2010) South Australia s Cool roofs Regulation A Discussion Paper, online: cussion_paper.pdf Page 10 of 29

11 Residential Buildings No additional requirements are currently being investigated for cool roofs on residential buildings in South Australia. However, as the BCA permits reduced insulation for roofs with lower solar absorptance, the Government of South Australia estimate that this provides a saving of approximately $2.76 per square metre in insulation costs, providing an incentive for cool roofs. Roofs with a solar absorptance value of more than 0.6 are required to install even more insulation, providing a disincentive for dark roofs. 13 Western Australia The Residential Design Codes of Western Australia 14 warn of the potential for glare and discomfort to neighbours from the use of highly reflective roofs. They suggest that, in some situations, designers should use light, less-reflective roofing materials or finish, such as a light Colorbond, rather than highly reflective materials, such as Zincalume. 13 Government of South Australia (2010) South Australia s Cool roofs Regulation A Discussion Paper, online: cussion_paper.pdf 14 Western Australian Planning Commission (2008) Residential Design Codes of Western Australia Explanatory Guidelines, State of Western Australia, p. 35, online: Page 11 of 29

12 4. Local Government Development and Planning Policies An investigation into policies and initiatives that could be implemented at a local level has been undertaken in order to discern if any Councils around Australia currently have provisions related to cool roofs that may provide insight into how Townsville City Council could help encourage or mandate the uptake of cool roofs. There are several areas of policy that could affect the use of reflective building materials, and therefore several councils are creating policy documents that deal with this subject directly. Some Councils contacted expressed the opinion that implementing planning policies or sustainability assessment tools at a local level was less ideal than implementing these measures at a regional or State level. However, in the absence of current initiatives at those levels of government, local initiatives can provide an adequate measure. Reflective building materials policies Several Local councils have developed reflective building material polices that could affect cool roofs. The major concern from a legislative perspective for many councils was originally to protect the community from development that negatively impacts visual amenity. It is now becoming more necessary to ensure that they meet updated sustainability criteria. Since reflective materials are often suitable for roofs from an energy efficiency perspective, councils such as Shoalhaven NSW, 15 Jerramungup WA, 16 and Busselton WA 17 are creating specific policies that deal with this particular conflict directly. Scenic amenity policies Scenic amenity is an important consideration in local and regional planning with a number of guidelines and policies that identify and protect areas of high scenic amenity value. There are two primary considerations that impact cool roofs in identified scenic amenity areas. Firstly, the use of light colours and visually reflective materials may stand out from the landscape and impact the landscape value of an area. Secondly, such surfaces may in some circumstances be more prone to glare. Barriers to the control and assessment of glare from cool roofs Smooth surfaces, more likely to be painted with reflective coatings, result in smaller areas of higher glare than textured surfaces (e.g., tiles, shingles). Smooth surfaces reflect light directly, similar to a mirror, whereas textured surfaces scatter light. In 2006, the State Administrative Tribunal of Western Australia endorsed the strong restriction of Zincalume surfaces relatively smooth, reflective surfaces that affect areas of significant natural feature Development & Environmental Services Group (n.d.) Reflective Building Materials Use in Coastal and Rural Areas, Shoalhaven City Council, online: doc.shoalhaven.nsw.gov.au/displaydoc.aspx?record=pol08/ Shire of Jerramungup (n.d.) Local Planning Policy No 5 Use of Reflective Building Materials, online: 17 Busselton Shire Council (2010) Special Character Areas and Visual Management Policy, Busselton Shire Council, t%20policy%20feb% pdf 18 Busselton Shire Council (2010) Direction Paper Review of the Use of Reflective Building Materials Policy, Busselton Shire Council, online: Page 12 of 29

13 In 2005, the New South Wales Land and Environment Court determined that landscaping, alone, is generally-ineffective at mitigating the effects of glare. 19 It argued that Screening vegetation requires continual maintenance by the current and successive land owners, but such maintenance cannot be guaranteed through normal planning controls. Residents are more likely to be affected by glare when buildings are in close proximity, especially when neighbouring buildings have heights that differ by one storey or more. Restrictions that govern the use of reflective building materials in built up areas are often conservative so as to account for the worst case scenario. Such restrictions, however, can lead to the selection of surfaces and finishes that have poor energy efficiency performance. The effect of glare on residents can be quantified with parameters such as the orientation, slope of site, elevation, roof pitch, reflectance of the product, shading, vegetation, and adjoining development. Ideally, proposals for reflective roofs should be assessed individually. In doing so, however, planners will need new tools that ingrate these parameters, applicants will bear higher costs, and the approval process will take longer. Few consultants in Australia can accurate determine the impact of glare, and the service is costly. 20 Queensland Local Governments Townsville City Council Townsville City Council has recently been amalgamated and is currently investigating changes to many of the local planning provisions. There-in lies opportunity to include energy efficiency measures can provide benefits to residents and local industry. These measures are to work in conjunction with state and national policies. Cool roofs should be investigated as they are particularly well suited to tropical locations due to the high year-round temperatures and high solar irradiance. The draft Townsville City Council Scenic Amenity development requirement has a number of provisions relating to reflectivity of building materials in areas of high scenic amenity value. Cairns Under the Sustainable Building Policy for commercial buildings, dark colours are not permitted for roofs and walls exposed to the sun. 21 The policy however does not define these colours, and is therefore subject to some degree of subjectivity. Adopting the original BCA guideline for their climate could be an effective communication tool for this purpose. Moreton Bay Pine Rivers The Moreton Bay Regional Council, which covers the Pine Rivers district, specifies that buildings and structures that are visible from key lookouts and landmarks use colours and predominantly- 19 Busselton Shire Council (2010) Direction Paper Review of the Use of Reflective Building Materials Policy, Busselton Shire Council, online: 20 Busselton Shire Council (2010) Direction Paper Review of the Use of Reflective Building Materials Policy, Busselton Shire Council, online: 21 Cairns Regional Council (2001), Sustainable Tropical Building Design Guidelines for Commercial Buildings, online: data/assets/pdf_file/0003/45642/buildingdesign.pdf, accessed 8 June 2012 Page 13 of 29

14 non-reflective materials that minimise glare. 22 The Council adopts the list of acceptable roof colours, most of which are dark, from the Australian Standard AS 2700s Scenic rural overlay codes graphically depict the form of the acceptable landscape forms. The guide displays situations where it would be unacceptable to adopt a reflective roof due to glare issues. Typical situations are to retain visual amenity to lookouts and high scenic value areas. The design of site orientation and visual barriers such as trees are recommended to break the line of sight from the site of reflection. Another measure enforced is the reduction of highly reflective surfaces on the north to less than thirty percent. 23 Other Australian Local Governments Victoria The City of Melbourne recognises the benefits of cool roofs for commercial buildings and encourages their adoption through the 1200 Buildings Program. 24 However, Melbourne City Council does not have any requirements within development and planning regulations stipulating cool roof requirements. Western Australia Fremantle The City of Fremantle, Western Australia issued a white paper that acknowledges light coloured roofs as an energy efficient feature. The paper notes that lighter colours should be used to reflect the sun s heat. They recommend not using white, especially where a neighbour can be affected by glare. A colour scheme is to be use for other parts of the building. This is also therefore relevant for the facade, as glare can be generated through white walls predominately on the east or west. Traditional Zincalum is acceptable as it fades to below the reflectance of white. 25 Subiaco The City of Subiaco specifies a two-level assessment process for new or replacement roofing on a proposed development for the potential impact of reflective glare on adjacent properties directly in line and within 35m of the roof. 26 The process might preclude the construction of highly Subiaco defines the following materials as highly reflective for the purposes of the Reflective Roofing policy: 27 Zinc or Zinc-Aluminium alloy coated steel or polished metal, e.g. Zincalume, galvanized (iron) steel, stainless steel, aluminium, copper (where sealed against oxidation) Glazed tiles (irrespective of colour) 22 Moreton Bay Regional Council (n.d.) PineRiversPlan - Planning Scheme, Chapter 5, Part 5 Significant Cultural Heritage Sites Overlay Code, online: 23 Moreton Bay Regional Council (n.d.) PineRiversPlan - Planning Scheme, Chapter 5, Part 5 Significant Cultural Heritage Sites Overlay Code, online: 24 City of Melbourne (n.d.) Cool roofs, online: 25 City of Fremantle (2000), Energy Efficient Building Design. City of Fremantle, Western Australia, Policy Number D.B.H City of Subiaco (2006) Reflective Roofing, online: 27 City of Subiaco (2006) Reflective Roofing, online: Page 14 of 29

15 Glass or Perspex High-Gloss painted finishes, unless heavily textured (whether tile or metal) High gloss coated finishes other than paint, e.g. enamel The following materials are defined as not being highly reflective Concrete or clay tiles other than glazed or high-gloss finishes Painted or pre-painted finishes other than high-gloss, e.g. Colorbond steel The City tried to codify a set of design parameters for reflective roofs. The approach is very subjective, leads to delays to approvals, and can get the City involved into disputes between neighbours over reflectance. The approach required staff who are trained in the science of specular glare or reflectance. 28 Busselton Busselton Shire in south west, Western Australia has a visual management strategy that addresses reflective building materials. Limitations have been imposed on certain building materials in certain areas to maintain visual amenity. As of the effective date of 14 May 2010, certain materials identified within the policy are not to be used. The materials are relevant to both the roof and the facade and cover Landscape Value Areas and Travel Route Areas. 29 The following is an extract that demonstrates some prohibited materials; 30 Zincalume (including any zinc or Zinc-Aluminium coated sheet or polished metal), Light and Very Light building materials (as classified according to BCA definitions) Stainless steel, Copper (where sealed against oxidation), Glazed terra cotta tiles (irrespective of colour), High Gloss painted finishes with a light reflectance and/or chroma value exceeding 50%, Large expanses of tinted or clear glass or Perspex (transparent and translucent acrylic). The policy also introduces some flexibility by allowing the use of highly reflective building materials where it can be demonstrated that an applicant will mitigate glare or amenity impacts. This includes the use of shielding vegetation, consultation with neighbouring properties, and appropriate construction locations to ensure the structure cannot be seen from public areas (see Appendix. The terms light and very light building materials are defined by using a modified Colour Classification adopted from the NCC Building Code of Australia (see figure 2). 31 The policy document presents a simple structure for the determination of roofing materials. 28 Busselton Shire Council (2010) Reflective Building Materials: Officer s Report, Draft, Busselton Shire Council. 29 Busselton Shire Council (2010) Special Character Areas and Visual Management Policy, Busselton Shire Council, t%20policy%20feb% pdf 30 Busselton Shire Council (2010) Special Character Areas and Visual Management Policy, Busselton Shire Council, t%20policy%20feb% pdf Page 15 of 29

16 Figure 2: Bluescope Steel colours used for the classification of an appropriate roofing colour The use of solar absorptance to classify what is visually reflective is less than ideal, as solar absorptance considers ultraviolet, visible, and near-infrared wavelengths. Ultraviolet and nearinfrared light cannot impact the visible appearance of a material. In 2010, the Shire reviewed and updated its Reflective Building Materials Policy in order to minimise productivity impacts, accelerate approvals, and avoid extra cost for applicants. The following list highlights relevant updates: 32 The previous policy ruled on visual reflectivity using solar reflectance, a measure that is inaccurate for measuring glare and that is not usually used to measure the performance of building materials. The new policy controls materials according BlueScope Steel classification, based upon the Building Code of Australia. 31 Busselton Shire Council (2010) Special Character Areas and Visual Management Policy, Busselton Shire Council, t%20policy%20feb% pdf 32 Busselton Shire Council (2010) Direction Paper Review of the Use of Reflective Building Materials Policy, Busselton Shire Council, online: Busselton Shire Council (2010) Reflective Building Materials: Officer s Report, Draft, Busselton Shire Council. Page 16 of 29

17 The previous policy limited the use of materials with solar reflectance greater than 50% in visually prominent landscape areas, such as scenic areas and views from tourist routes. The new policy allows the use of light-coloured materials in areas where the risks are low. The new policy also allows the use of highly-reflective roofing materials when the applicant can demonstrate that, overall (materials, design, location, and circumstances), no negative amenity or landscape impact will occur. A previous policy precluded the use of reflective and light materials within Conservation, Bushland Protection, or Rural Landscape zones. The new policy supports these conditions. The previous policy targeted only metal roofing products. The new policy controls metal and other materials that potentially cause glare issues. The previous policy precludes metal products on walls and reflective materials on low sloping roofs in residential areas. The new policy does not require approval for the use of reflective wall cladding within town sites because the risks of negative impacts are low. The new policy still broadly controls the use of very light roofing products because (a) the Shire deems that the potential for improvements in energy efficiency was outweighed by the potential for the negative impacts on scenic amenity; and (b) the tools required for individual assessment of proposed reflective roofs are unavailable or cost-prohibitive. Busselton Shire Council, being located in a temperate climate, deemed that cool roofs would offer only slight energy efficiency improvements. The Shire argues that very light roofing products would lead to improvement in the thermal efficiency of buildings in the warmer climate zones 1-3, which encompass Townsville. Melville The City of Melville in Western Australia has a policy on the use of highly reflective roofing materials for residential and non-residential buildings. The policy recognises the internal temperature and energy efficiency implications of reflective roof materials. The use of highly reflective roofing materials is endorsed by the city provided certain criteria are met (see Appendix 1). It defines properties that can be potentially affected by glare as those located within 80 and 290 degrees due north of the subject site. Glare is influenced by building orientation, the angle of the roof pitch, the location of major openings on adjoining properties, and the existence of screening. Jerramungup The Shire of Jerramungup specifies that reflective materials on all residential development in the Townsite zone, Town Centre zone, and all Residential zones must not be visible from nearby properties, must not be visually prominent from a main road or public place, must not cause any nuisance or glare to surrounding residents, and must not detrimentally affect the scenic amenity. 33 The Shire also specifies that all outbuildings in the Townsite zone and Residential 33 Shire of Jerramungup (n.d.) Local Planning Policy No 5 Use of Reflective Building Materials, online: Page 17 of 29

18 zone might require construction out of non-reflective materials, accounting for factors such as visual impact, wall height, screening vegetation, and the use of adjacent properties. 34 Emu Point Development Emu Point Development, Albany on the South Coast of WA, has implemented constraints on the reflectivity of building materials. The development site is an environmentally sensitive area and therefore must be assessed under various environmental codes. The area is known for its environmental assets and heritage sites. To ensure a coherent development process, a colour palette has been selected that aims to strike a balance between energy performance and blending in to the existing environment. 35 Roof colours are to fall between the BCA Colour Absorptance figures of 0.40 and 0.62, with ZincAlume roofing as an exception. Taking into consideration that this development is on the southern tip of Australia, these values are likely to be able to be appropriate for this development. Townsville is significantly hotter year round, and could benefit from more stringent requirements. 36 New South Wales Shoalhaven Shoalhaven, NSW, has a policy on the use of reflective building materials in coastal and rural areas. 37 Policy POL08/190 is a performance-based policy designed to avoid imposing a blanket ban on all reflective building materials. The policy permits the use of traditional building materials (for example, galvanized steel) as long as certain conditions are met (see table below). Shoalhaven deliberately introduced some flexibility into the policy in order to facilitate the innovative use of these materials and skillful siting of buildings to ensure areas with scenic value are maintained. It also protects the reasonable amenity of other property owners with views to the site. However the policy does not actively encourage the use of reflective materials such as pre-coloured Colorbond steel. Performance criteria P1 Buildings in coastal and rural areas should be designed and constructed so as not to intrude into the landscape and/or interrupt views from public places and private property to which the public has regular access. The Acceptable Solutions This can be achieved by incorporating the following design features into a development: Siting - below ridgelines and/or knolls in a location which does not have a direct line of sight to any other dwelling house, public road, public place or place frequented by the public. Screening taking advantage of existing vegetation 34 Shire of Jerramungup (n.d.) Local Planning Policy No 16 Outbuildings, online: 35 GHD (2010), Emu Point Residential Development - Design Guidelines, Prepared by GHD for Landcorp, E.pdf, accessed 28 June GHD (2010), Emu Point Residential Development - Design Guidelines, Prepared by GHD for Landcorp, E.pdf, accessed 28 June Shoalhaven City Council (2004), Reflective Building Materials Use in Coastal and Rural Areas, Online: accessed 28 June Page 18 of 29

19 P2 reasonable amenity of any property owner with views to the building site should also be protected. Traditional building materials, such as galvanised steel, may be permitted in the following circumstances: to provide a backdrop to and screening for buildings and/or the introduction of screen planting. Design roof pitch and orientation designed to eliminate reflectivity and glare. Materials the use of materials which will complement the design of the building and reflect traditional building styles. A visual assessment has been undertaken by the applicant which demonstrates that the building would not have a significant visual impact when viewed from any public road, public place, private property to which the public has access, National Park, walking trail or other dwelling. Use of traditional building materials is justified in the context of the design of the building. Tumut Tumut Shire Council, west of Canberra, acknowledges nuisance glare and have developed policy to deal with issue. They have adopted a case-by-case assessment system for applications to install metal roofing. It is recommended that all metal roofs should be painted, and that they are subject to public opinion through the standard public notification system. Buildings are to use materials that ensure reflection and glare do not adversely affect surrounding properties. 38 Rural areas are also protected by a Rural Residential Development control plan. The purpose of this document is aimed to preserve rural character through the minimisation of visual impacts Tumut Shire Council (2009), Metal Glad Buildings Policy, Tumut Shire Council, NSW, Australia, online: /uploaded_files/documents/bld.01%20metal%20clad%20buildings%20policy pdf, accessed 8 June Tumut Shire Council (2009), Metal Glad Buildings Policy, Tumut Shire Council, NSW, Australia, online: /uploaded_files/documents/bld.01%20metal%20clad%20buildings%20policy pdf, accessed 8 June Page 19 of 29

20 5. International trends Cool roof legislation is becoming more common internationally, with many governments in the United States and Europe in particular introducing requirements into their standards and codes. A number of international examples have been investigated and are summarised below. International Code Council Cool roof measures are included in the International Code Council s International Energy Conservation Code The code adopts standards as set out in AHRAE New Zealand Queenstown Lakes District Council protects the natural resource character of the region from glare and reflective building materials. Policies favour matt or non-shiny surfaces; and prohibit Zincalume, reflectance value greater than 35%, large expanses of glass, and large smooth surfaces. 40 European Union The European Commission is actively supporting cool roofs to help increase uptake. Energy efficiency policies set by national and local governments, as well as other European Union institutions, is helping to promote cool roofs. The EU cool roof project consortium is represented primarily by Greece, Italy, France and the UK. 41 A Policy Landscape Assessment investigated the spread of policies that could potentially impact the acceleration of cool roofs on the European market, including key policies that are urgent and significant for the uptake of cool roofs. The policies fell into three main categories: building regulations, standardisation, and financial incentives. United Kingdom: The Building Research Establishment Environmental Assessment Method (BREEAM) is a voluntary environmental assessment method and rating system for buildings. In the UK, cool materials are included in the BREEAM rating system as a heat island mitigation strategy. Greece: The Greek Ministry of Environment, Energy and Climate Change announced The Building the Future program in 2010 to provide over three million energy efficiency interventions in buildings throughout Greece. This includes incentives for the application of 20,000 cool roofs on residential buildings and issued directives promoting the use of cool materials as energy efficiency measures. 42 Italy: Italy has introduced directives promoting the use of cool materials as energy efficiency measures. Germany: The Sustainable Building Certificate includes cool materials in the rating system as a heat island mitigation strategy. 40 Busselton Shire Council (2010) Direction Paper Review of the Use of Reflective Building Materials Policy, Busselton Shire Council, online: 41 European CoolRoofs Project (2010) Policy, legislation and cool roofs incentive, online, 42 BuildUp (2010) The Greek Ministry announced the programme "Building the Future", online: Page 20 of 29

21 United States of America In the USA, Standards 90.1 and 90.2 stipulate energy standards for non-residential and residential buildings defines a cool roof for non-residential buildings in particular climate zones as having a minimum initial solar reflectance of 0.7 and a minimum thermal emittance of Values of solar reflectance and thermal emittance together are used to define a coating s Solar Reflective Index (SRI) stipulates a minimum SRI of 64. The standard also requires solar reflectance and thermal emittance values to be determined by a laboratory accredited by a nationally recognised accreditation organisation defines a cool roof for a low-rise residential building in specific climate zones as having a minimum solar reflectance of 0.70 and a minimum thermal emittance of 0.75, resulting in a total SRI of Residential buildings with cool roofs are permitted to have a lower R-value and a higher U-value. Standard defines a cool roof for green buildings (excluding low-rise residential buildings) in specific climate zones as having a minimum initial SRI of 78 for low-slope roofs, having an initial SRI of 29 for steep-slope roofs, or complying with the criteria for USEPA s ENERGY STAR roof products. 45 These levels of performance must hold for 75% of the unoccupied roof surface. Throughout the USA, many States and local municipalities have introduced cool roof requirements. The following is a list of cool roof standards, building codes, rating, and labeling in the U.S.A. 46 Standard prescribes cool materials for low-sloped roofs on nonresidential buildings in some U.S. climates. Standards and offer credits for cool materials for lowsloped roofs on nonresidential buildings in some U.S. climates. Standard offers credits for cool materials for all roofs on residential buildings in some U.S. climate zones. Standard offers credits for cool materials for all roofs on residential buildings in some U.S. climate zones. California s Title 24 Standards (2008) encourage cool materials for roofs on residential and nonresidential buildings in some California climate zones. It stipulates the use of threeyear aged solar reflectance data for the purpose of defining allowed cool roof coatings. 47 California s previous Title 24 Standards from 2005 prescribe cool materials for low-sloped roofs on nonresidential buildings in all California climate zones (but one coastal region) 43 (2007) Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings, American Society of Heating, Refrigerating and Air-Conditioning, online: 44 (2007) Standard 90.2: Energy Efficient Design of Low-Rise Residential Buildings, American Society of Heating, Refrigerating and Air-Conditioning, online: 45 (2011) Standard 189.1: Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings, p. 16, online: 46 Akbari, H., Menon, S., & Rosenfeld, A. (2008). Global cooling: increasing world-wide urban albedos to offset CO2. Climatic Change, 94(3-4), California Energy Comission (2008) Energy Efficiency Standards for Residential and Nonresidential Buildings, online: Page 21 of 29

22 and offers credits for steep-sloped roofs on residential and nonresidential buildings in all California climate zones. The 2003 International Energy Conservation Code allows commercial buildings to comply by satisfying the requirements of Standard 90.1, which at the time that IECC 2003 was written offered cool-roof credits. The Chicago, IL Energy Conservation Code prescribes a minimum solar reflectance and thermal emittance for low-sloped roofs. It specifies the use of either a minimum initial solar reflectance value of 0.72, or a three-year aged value of Standards for medium-sloped roofs are less stringent, requiring a minimum initial value of only Steep-sloped roofs are exempt. Cool roof products must be rated by the Cool Roof Rating Council or ENERGYSTAR. 48 The 2004 Florida Building Code prescribes cool materials for all roofs on non residential buildings that are essentially the same as those in Standard Hawaii. In 2001, 2002, and 2005, respectively, the counties of Honolulu, Kauai, and Maui adopted cool-roof credits for commercial and high-rise residential buildings based on Standard The Dallas City Council requires low-sloped commercial buildings over 50,000 square feet to have a minimum initial solar reflectance value of 0.65 and a minimum three-year aged value of U.S. EPA ENERGY STAR Label. The U.S. EPA currently requires that low-sloped roofing products have initial and three-year-aged solar reflectances not less than 0.65 and 0.50, respectively. Steep-sloped roofing products must have initial and three-year-aged solar reflectances not less than 0.25 and 0.15, respectively. Due to the accumulation of surface particles like dust and air pollutants on roof materials, the solar reflectance tends to decrease over time. Steep roofs help to reduce the build-up of these through the action of water cleaning the surface. 50 LEED Green Building Rating System. The Leadership in Energy and Environmental Design (LEED) Green Building Rating System assigns one rating point for the use of a cool roof in its Sustainable Sites Credit. Cool Roof Rating Council. The Cool Roof Rating Council was established in 1998 to develop accurate and credible methods for evaluating and labeling the solar reflectance and thermal emittance (radiative properties) of roofing products and to disseminate the information to all interested parties. 48 City of Chicago (2009) 49 City of Dallas (2008) 50 RCI (2009), Benefits and Trade-Offs of low-slope roofing system insulation and reflectance, online: online: accessed 28 June Page 22 of 29

23 Table 2: Cool roof codes and standards (compiled by Cool Roof Rating Council) Agency Cool roof policy Solar reflectance Thermal emittance United States 90.1 (Commercial Buildings) and 90.2 (Residential Buildings) If a cool roof is used in climate zones 1, 2 or 3, the minimum requirement for insulation is reduced. CRRC is recognized as an informative reference Arizona, Arizona Energy Commission /IESNA Mandatory for all state owned and funded buildings Arkansas, Arkansas Energy Office 2004 Arkansas Energy Code for New Building Construction 2003 IECC for residential buildings; 2003 IECC and for commercial buildings Austin, TX, City of Austin Austin's 2006 Energy Code Requirement based on the Austin Energy Green Building Ratings and/or LEED certification; varies by zoning, location and building type Low Slope: 0.70 or SRI= 78 Steep Slope: 0.35 or SRI=29 California, California Energy Commission Title CRRC Title Summary Performance credits for inclusion of cool roofs in buildings; CRRC named as supervisory entity 0.70 (varies by region/slope, reference CRRC Title Summary) 0.75 (varies by region/slope, reference CRRC Title Summary) Chicago, IL, Department of Buildings Chicago Energy Conservation Code Section through Labeled by the CRRC or ENERGY STAR Low Slope (0:12-2:12): Initial 0.72 OR Aged 0.5 Medium Slope (2:12-5:12): None Initial 0.15 Dallas, TX Dallas City Council Dallas Green Building Ordinance Section Comprehensive building standard for both residential and commercial construction Initial SR: 0.65 Aged SR: 0.50 None Florida Department of Community Affairs 2007 Florida Building Energy Code Ch Performance-based (earn a credit) for residential buildings. CRRC recognized in code Georgia Department of Community Affairs Georgia Construction Code /IESNA Mandatory statewide for commercial buildings Hawaii Hawaii Department of Business Economic 2006 IECC Code, with the exception of Kauai County's Energy Code Mandatory in specific counties for commercial buildings See the 2006 IECC Code. Kauai County: 0.75 Other counties: See the 2006 IECC Code Page 23 of 29

24 Agency Cool roof policy Solar reflectance Thermal emittance Development and Tourism Houston, TX City of Houston City of Houston Commercial Energy Conservation Code Commercial Energy Conservation Code based on with amendments Low Slope: 0.70 Low Slope: 0.75 Louisiana Natural Resources/ Technology Assessment Division /IESNA (and 2006 IECC for buildings not covered by ) Mandatory statewide for commercial buildings New Mexico Energy, Minerals and Natural Resources Department /IESNA Mandatory statewide for commercial buildings New York New York City New York City Building Code 2008 Ch. 15 Mandatory citywide for all new buildings Low Slope (3:12 or less): white colored or Energy Star rated None North Carolina Department of Insurance /IESNA IECC and Standard for nonresidential buildings; IECC 2003 compliance for residential South Carolina South Carolina Energy Office 2006 IECC with reference to /IESNA Mandatory state-wide for commercial and residential buildings Texas State Energy Conservation Office /IESNA Mandatory for all state funded buildings Commonwealth of the Northern Mariana Islands Department of Public Works Model Tropical Energy Code Mandatory for all new and renovated nonresidential and residential, prescriptive roofing requirements, must be rated by the CRRC Low-slope: Aged Solar Reflectance 0.55, Thermal Emittance 0.75 OR SRI 64 In the U.S.A, much work has been done in relation to cool roof standards and guides, and this provides a great resource to help shape the direction of initiatives in Australia. An extract from Page 24 of 29

25 the NYC Department of Design and Construction cool and green roof manual demonstrates the work developed as of 2003 in America: 51 Japan - LEED certification program, which has an SRI calculator, as well as established criteria - Cool Roof Rating Council, which administers a rating program in the U.S.A. that covers the radiative properties of cool roof products. Products may be tested in accredited laboratories and then be placed in the CRRC Product Directory, which publishes results by type and brand name. - Energy Star, which has established criteria and lists compliant commercial products - Lawrence Berkeley Lab, which lists tested results for generic and specific products - Oakridge National Lab, which has tested reflectance /emittance over time, including SRI and calculator - California Cool Roof Information, which hosts a Qualified Cool Roofs Products List of products that meet California s Title 24 Requirements - /IES, which considers cool roof - insulation trade-offs in Standard The guide further details construction types, costs, and trade-offs between the various constructions. CASBEE Standard for New Construction offers credits for cool materials for all roofs and for countermeasures against light pollution (illumination and glare) on buildings in Japan. 52 In Tokyo the minimum solar reflectance of Cool Roofs is 50 percent. These materials are recommended to maintain 80 percent of the initial solar reflectance value after two years of exposure. 53 They particularly target materials that are effective long wave length reflectors. Interestingly, the use of these materials is not recommended on the sides of buildings, as it adversely affects the urban heating. India, Delhi Government officials have proposed cool roofs for buildings in Delhi. The Bureau of Energy Efficiency (BEE) will develop a Cool Roof Manual to improve energy efficiency. The aim of the manual is to give agencies and residents the necessary information of the various technologies. Initial studies indicate a 50 percent reduction in surface temperature. It is hoped that cool roofs will reduce peak electricity loads during summer, through more acceptable indoor temperatures Department of Design and Construction (DCC) (2007), DDC Green and Cool Roofing Manual, New York City, DCC, accessed 8 June CASBEE Standard for New Construction: Technical Manual, Japan GreenBuild Council / Japan Sustainable Building Consortium, p. 184, 188, , online: 53 CASBEE (2010), Comprehensive Assessment System for Building Environment Efficiency, Japan Sustainable Building Consortium (JSBC), online: accessed 8 June Bureau of Energy Efficiency (2011) BEELine - April Edition, Bureau of Energy Efficiency, India, online: accessed 8 June 2012 Page 25 of 29

26 6. Summary Cool Roof policies and guidelines have been developed significantly around the world, particularly in the USA, however has been limited within Australia. Guidelines and policies within Australia generally surround the issue of glare and visual amenity. Roof performance requirements are governed by The Building Code of Australia which varies the amount of insulation necessary depending on the solar absorptance of the roof. The energy efficiency of new buildings are considerably better than they were years ago when many of the homes were built in Townsville. However, excessive air-conditioning loads are imposed on the electricity grid as a result of the amount of air-conditioning units being installed on older style homes, many of which have roofs that excessively heat the home. Most of the guidelines around cool roofs encourage the use of solar reflectance values above 0.70 for low slope roofs, and lower values for high sloped roofs. 55 The following report will discuss specific policy recommendations built upon this investigation of local and international government inclusions of cool roofs. 55 (2007) Standard 90.2: Energy Efficient Design of Low-Rise Residential Buildings, American Society of Heating, Refrigerating and Air-Conditioning, online: City of Chicago (2009) Page 26 of 29

27 Appendix 1: Busselton Reflective Building materials policy notes: The use of highly reflective roofing materials will be endorsed by the city provided at least one of the following criteria is met: (a) Where consultation takes place and no adverse comments are received in response; or (b) Where the pitch of the roof is less than 15 degrees (as shown in Figure 4 below) and where the adjoining property (located within 80 and 290 degrees due north) has no major openings facing the subject site above ground floor level; or (c) Where the pitch of the roof is greater than 35 degrees (as shown in Figure 5 below); or Page 27 of 29