RdSAP METHODOLOGY MANUAL. Stroma Certification March 2013 RdSAP Methodology Manual Edition 2.0

Transcription

1 RdSAP METHODOLOGY MANUAL Stroma Certification March 2013 RdSAP Methodology Manual Edition 2.0

2 CONTENTS Contents 1.1 RSAP+ : A GUIDE TO STROMA S RDSAP SOFTWARE INTRODUCTION TO EPCS PROPERTY DESCRIPTION PROPERTY AGE CONSTRUCTION AND INSULATION PROPERTY ELEMENTS PROPERTY SIZE SPACE HEATING WATER HEATING RENEWABLE TECHNOLOGIES

3 A Guide to Stroma s RdSAP Software 1.1 RSAP+: A GUIDE TO STROMA S RDSAP SOFTWARE Stroma offers RSAP+ software solutions free of charge to all Stroma DEA scheme members. All of Stroma s RSAP+ software uses the latest version of Stroma s Approved Calculation Tool to calculate the EPC ratings and for the lodgement of the EPC. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 3

4 1.1 RSAP+: A GUIDE TO STROMA S RDSAP SOFTWARE Desktop version available Free-of-charge to download from ipad app available Free-of-charge to download. Just search for Stroma on the app store. RSAP+, created by Stroma Certification, is software designed to facilitate conducting an Energy Performance Certificate (EPC) efficiently, securely, and in compliance with all relevant standards. The software is available in both desktop and tablet ios applications, and includes the new Green Deal EPC standards. The app available for ipad can produce an EPC offline; therefore internet connections are not relied upon when Energy Assessors conduct a property assessment. RSAP+ is based around the Reduced Data Standard Assessment Procedure (RdSAP) developed by the Government for use in assessing existing dwellings; this is a system of property data collection, together with defaults and inference procedures, that generates a complete set of input data for calculation. To enable the energy ratings of properties to be fairly compared, RdSAP has been designed to assess the building rather than its occupants. This means that individual household behaviour is irrelevant and an Occupancy Assessment (OA) would be required to assess behavioural attributes for a Green Deal Assessment. RdSAP makes the following behavioural assumptions: Standard occupancy - the size of the dwelling determines the number of occupants and therefore the hot water requirement. Standard heating pattern - the heating requirement is based on the volume of the dwelling, following standard heating patterns of 9 hours heating a day during the week and 16 hours a day at the weekend. The living area is heated to 21 o C and the rest of the house to 18 o C. RSAP+ additionally draws information from databases within the Product Characteristic Data File (PCDF), a regularly-maintained database through which certified Energy Assessors can locate appropriately-calculated seasonal efficiencies and characteristics for heating and related products; this therefore reduces the risk of miscalculation and confusion with data. Stroma Certification s RSAP+ is Government approved software integral to the EPC application; it presents the recommendation of measures and the EPC banding the Green Deal EPC would generate, and then allows the certified Green Deal Advisor (GDA) to adjust the measures/improvements to client preference and suitability, before building the Green Deal EPC for the property. 4

5 RSAP+ Features: Streamlined EPC process. Provides survey requirement prompts, using a traffic light format, in a clear user interface. Completes calculations on the ipad device without the need for Internet access, speeding up the assessment process. Flags any missing information within the Desktop Application with a clear error icon, speeding up the assessment process. Stores survey data, including all site notes and photography, within OSA 15. Facilitates lodgement in seconds. 1.1 RSAP+: A GUIDE TO STROMA S RDSAP SOFTWARE RSAP+ Technical Functions: Creates EPCs via the approved RdSAP methodologies for domestic properties. Collects survey data to produce EPCs and lodges directly on the Desktop, ipad, or Web applications References and stores EPCs automatically, in an easy-to-use filing system. Allows work to be saved at any point to be completed at a later date. Extracts all lodged survey details into Microsoft Excel for analysis. Automatically backs up survey and Green Deal EPC data, via Stroma s OSA15 online storage system. A PCDF database or boiler database, which can also be stored on the ipad, allows DEAs and GDAs to search by boiler type. Address lookup allows address details and UPRN to be downloaded into the survey. *Requires internet connection Add address feature allows addresses not stored in Landmark to be added. *Requires internet connection Traffic light system guides GDAs through the survey section process, highlighting non-conformities or incomplete sections. Camera feature, on the mobile device*, automatically names photos and stores them in the correct sections, and uploads directly to Stroma at lodgement. *Requires ipad 2 or later Prompts secondary survey actions for investigating the application of specific measures. DEAs and GDAs can manage their account using the members area connections. Synchronises data with Stroma Certification s GDAS Module. Meets certification auditing requirements. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 5

6 1.2 INTRODUCTION TO EPCS Introduction to EPCs This chapter will cover: Background to EPCs EPC Legislation Survey Procedure and RdSAP EPC Recommendations What is an EPC? Energy Performance Certificates (EPCs) are the Government s chosen way of complying with the Energy Performance of Building Directive (EPBD). Its purpose is to record how energy efficient a property is. The certificate will provide a rating of the energy efficiency and CO 2 emissions of a building from A to G, where A is very efficient and G is very inefficient. Why Were EPCs Introduced? The Energy Performance of Buildings Directive began the implementation of EPCs throughout Europe. The Housing Act 2004 is the UK s legislation specific to EPCs; introducing the EPC to England and Wales in August 2007, followed by Northern Ireland (June 2008) then Scotland (December 2008). EPCs are required for homes which are put up for sale or rental across the whole of the UK. What Does a Domestic EPC Include? The EPC is designed to give informative and useful information to the reader. It is usually 4 pages long and includes: Page 1 An Energy Efficiency rating between A and G, following the style used for fridges and washing machines. Estimated energy costs and savings averaged over a three year period. The top three recommendations for the property, their typical cost and the savings they would provide Brief green deal information Page 2 A building summary with statements about elements of the building based on data recorded by the DEA, including construction and insulation details, the heating system and hot water system More in depth information about Green Deal and how the financing works. Page 3 Full list of cost effective recommendations for the dwelling, their indicative cost, typical savings, and whether they can be financed fully or partly through the Green Deal. List of possible 'alternative measures', these measures improve the energy efficiency of the dwelling, but do not have costs or savings associated with them. The Green Deal Package - this lists all the recommendations which can be fully funded by the Green Deal Page 4 Energy assessor details including contact information Environmental impact rating - this is a rating of the carbon emissions of the dwelling and is a similar A to G rating as the Energy Efficiency rating 6

7 EPC Legislation How Long is an EPC Valid? If a property is being sold or rented the EPC must be less than 10 years old. Please note, the implementation of the EPC regulations for rental properties in October 2008 stated that an EPC would be required when a new tenant moves into the property. This means that any rental property with the same tenant since pre October 2008 will not need an EPC until the current tenant moves out. Which Properties Require an EPC? All commercial and domestic buildings being sold or rented require an EPC, with some exceptions: Buildings which are used primarily or solely as places of worship Temporary buildings with a planned use time of two years or less Industrial sites, workshops and non-residential agricultural buildings with low energy demand Stand-alone buildings with a total useful floor area of less than 50m 2 which are not dwellings Dwellings with relevant planning permissions for demolition The following situations require an EPC to be produced via a full SAP assessor: 1. A newly built dwelling. E.g. a property which has not yet been lived in and is being sold or offered 'to-let' by a developer or independent builder 2. A dwelling which is being sold or let following a material change of use. This means the building s use has been changed (usually from commercial use to domestic), including barn conversions and houses converted into flats The above is not an exhaustive list of all the situations when a DEA can not carry out the assessment. If there is any doubt regarding the authority of the DEA to assess a dwelling, the assessor should contact Stroma Certification technical support. It should be noted that a DEA creating an EPC in situations which require another qualification could be liable to possible prosecution. In all of the above cases, a SAP 2009 assessment is required in order to demonstrate compliance with Building Regulations. The EPC will be produced from this assessment. New dwellings that are still pending construction, or are under construction and not yet completed, (i.e. being sold 'off plan') will require a 'design-stage' Predicted Energy Assessment (SAP 2009) before the property can be marketed for sale. This will be superseded by the final 'as-built' SAP assessment and EPC on completion of construction. 1.2 INTRODUCTION TO EPCS Any building which has been listed by English Heritage. Listed buildings can be found online at list.english-heritage.org.uk When Can a DEA Not Produce an EPC? The EPC from the as-built SAP 2009 assessment is valid for 10 years from the date the EPC is produced. If a property is being re-sold or re-let within 10 years of completion, a copy of the EPC from the original SAP 2009 report should be sought. A DEA can only assess Existing Dwellings. Different qualifications are required to assess the following: Commercial buildings (NDEA) Public buildings (DEC assessor) Newly built dwellings (SAP Assessor) *Updates to the RdSAP Manual Since the Home Information Packs (HIPs) were retracted in May 2010 by the current coalition Government the validity period of an EPC has changed. The text, highlighted above in bold denotes the changes that have been made to reflect the retraction of HIPs. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 7

8 1.2 INTRODUCTION TO EPCS Dwellings of Multiple Occupancy - HMOs A House of Multiple Occupancy (HMO) is defined as a building with individual rooms which are rented out and share facilities such as kitchen and/or bathroom. Given that an EPC is only required for a self-contained unit, rented rooms within a HMO do not require an EPC (because the property includes shared facilities). However, if the whole building is sold it will require an EPC, either commercial or domestic, depending on the building type. Examples of HMOs: A house or flat rented by a number of tenants who have exclusive use of their bedroom but share a kitchen and bathroom. Each tenant has a contract with the landlord for the parts of the dwelling they have access to, but not for the whole dwelling Individual tenants rent rooms in a hall of residence; they share kitchen facilities, but have en-suite bathrooms. Each room does not constitute a self-contained unit as they share some facilities, and therefore do not require an EPC if rented Please Note: a house rented to a group of people on a single contract with the landlord is not classed as a HMO, as all the tenants are renting the whole dwelling. An EPC would be required on sale or rental of the dwelling. Annexes An annexe is part of a property which can be classed as a self-contained unit it provides living accommodation for a single household, including a kitchen and bathroom. Annexes are often purpose built for elderly relatives, but if the annexe is rented out then it will require an EPC. If the house and annexe are sold, then 2 EPCs are required - one for each dwelling. To be classed as an annexe the dwelling must: be a self-contained unit with living accommodation, including a kitchen and bathroom have it s own access, separate from the main house It is possible for an annexe to share a heating system and metering with the main house and still require its own EPC. Holiday homes Any property which is rented out must have an EPC, unless it is intended to be used for less than 4 months in a year). This means that many holiday lets require an EPC. (This regulation applies specifically to England and Wales). Exemptions include: Mobile homes, caravans and park homes; a certificate is only required for a building or part of a building which has walls, a roof, and an energy conditioned interior. Bed and breakfast accommodation; an EPC is not required when individual rooms are rented out, but if the whole building were to be sold then an EPC would be required. 8

9 Survey Procedure A DEA must visit site to collect information about the property. DEAs are not permitted to use a 3rd party to collect the information from a property, known as data gathering. Specific details about the property are recorded via site notes or an ipad/tablet device and the data recorded is entered into the software in order to produce an EPC. Site notes also act as a record of the survey and the data collected by the DEA, both for audit purposes and in case of complaint/question about the EPC in the future. Health and Safety As a lone worker operating in different surroundings every day, it is of the utmost importance that you are aware of any risks posed by the property, its surroundings and occupants. We advise carrying out a risk assessment as part of every survey, to note any risks identified. The main risks when carrying out an inspection are: 1.2 INTRODUCTION TO EPCS Site notes - usually supplied by certification schemes, record property age, construction details, heating system information etc, plus any additional notes of supporting information. The site notes often form the only evidence for some elements of an EPC, such as property age. It is therefore important that the evidence seen on site is noted down. This means that auditors understand why you may have made a decision, and allows you to provide supporting evidence if there is a complaint about the EPC Floor plan - showing outline of all storeys in the property with party walls/heat loss perimeter, dimensions, location of any extensions, conservatory and alternative wall. A room layout with location of heating controls and low energy lighting is useful Photos - provide vital supporting evidence for the data collected on site. Photos must be in focus and show sufficient detail of the element photographed. Photos required for each survey are: All elevations (front, rear, and side) Primary heating system Secondary heating system Wall insulation evidence Roof construction Windows Evidence of wall thickness Conservatory - evidence of seperation Loft insulation depth Additional photos if applicable: Weather Property location Issues with property loose roof tile, unsafe floor, asbestos present Occupants and property contents aggressive occupants, large or presence of aggressive animals or toxic substances Loft inspection hatch too high or located in dangerous position, i.e. over stairwell Vermin/pests rats, wasps, fleas If you feel the risks posed at a property are too great to continue the survey, advise the client of the risk. If action by the client is required, request they address this prior to recommencing the survey. Quality assurance checks All domestic assessors are subject to Quality Assurance Checks, often referred to as audits, by Certification Schemes under the regulations laid out by the Department for Communities and Local Government. The audits are desk based, and use the evidence gathered by DEAs to confirm the EPC in question is correct. It is therefore vital that good evidence is gathered when on site. Failure to provide all the required evidence can lead to the EPC failing the audit. For full details on Stroma s Quality Assurance policy, please visit the Stroma Members area and download the Monitoring Policy. Electric and gas meter LPG cylinder Heating controls Low energy light fittings Hot water cylinder and thermostat For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 9

10 1.2 INTRODUCTION TO EPCS RdSAP How Does it Work? What is RdSAP? An EPC is produced based on RdSAP Reduced Data Standard Assessment Procedure. This is the government approved calculation tool to produce EPCs for domestic properties. The RdSAP is derived from SAP (Standard Assessment Procedure) which is used to assess newly built dwellings. The DEA must collect data from a property and enter it into RdSAP software which calculates the rating and produces the EPC. The assessor can then lodge this with Landmark, the register used to hold all EPCs for England, Wales and Northern Ireland. Scottish EPCs are lodged with the Energy Savings Trust. RdSAP Conventions When producing an EPC, the conventions of RdSAP should be followed. Conventions are agreed between all DEA schemes and give clarification to a number of elements of RdSAP. As conventions are periodically discussed and updated, it is vital that DEAs keep up to date with the technical bulletins released by their DEA Scheme. Sometimes it may be difficult to decide between two options in the survey input. In these circumstances the worst case scenario of the two should be selected so as not to falsely improve the SAP rating. RdSAP Assumptions To enable the energy ratings of properties to be fairly compared, RdSAP has been designed to assess the building rather than its occupants. This means that individual household behaviour is irrelevant. The following assumptions are made by RdSAP: Standard occupancy the size of the dwelling determines the number of occupants and therefore the hot water requirement Standard heating pattern heating requirement is based on the volume of the dwelling with the following standard heating pattern: 9 hours heating a day during the week 16 hours a day at the weekend The living area is heated to 21 o C and the rest of the house to 18 o C RdSAP does not account for electrical appliances or non-fitted lighting, as it is assumed these will not be left by the current owner/occupier. In addition to the assumptions made for occupancy and heating patterns, further suppositions are made by the RdSAP software relating to information collected by the DEA. Window areas A ratio has been developed to calculate the average window area based on the age of the property and the floor area U-values This is the rate of heat loss through the windows, walls, floors and roof of a dwelling. The software assumes U-values for different constructions based on the building techniques and materials available during different age bands. It is possible to overwrite these assumed values where documentary evidence is available. See section 1.5 for details. What is a U-value? A U-value is the measure of the rate of heat loss of a wall, window, floor etc. It is measured in W/m 2 K (Watts per metre squared per degree Kelvin). The higher the U-value, the higher the rate of heat loss. A property with a wall construction of a high U-value will lose heat quickly compared to a property with a low U-value. U-values vary between different construction materials, methods and age bands. In addition to this, retrofit insulation will improve the U-value of most elements. This means it is important that all these elements are identified correctly. Please refer to the Property Age and the Construction and Insulation sections for further guidance. Building Regulations now stipulate the required U-value of various building elements, which means that regardless of construction type, more modern properties must meet a minimum U-value. Prior to this date U-values vary between different construction and insulation types. 10

11 Recommendations An EPC includes recommendations which improve the energy efficiency of the surveyed property, thereby reducing the running costs for the dwelling. These recommendations are generated based on the data entered into the software by the DEA. These recommendations must: Be suitable for the property - i.e. cavity insulation will only be recommended for a dwelling with cavity wall construction. Improve the EPC rating - the recommendation must increase the EPC rating by at least 1 point (or 0.5 points for low energy lighting). Recommendations included in an EPC show an indicative cost and typical savings for the property, calculated by RdSAP, if the recommendation is implemented. Suppressing a recommendation The RdSAP conventions state that a recommendation should only be removed if there is suitable visual or documentary evidence to show that the recommendation is not appropriate. For example, it is not always necessary to remove a recommendation if a property is listed or located in a conservation area. In this case the EPC states that it may be necessary to secure appropriate permissions to carry out work on a property. See Appendix T for a full list of current recommendations and the potential reasons for removing them. 1.2 INTRODUCTION TO EPCS The EPC also shows whether a recommendation can be fully or partly financed by the Green Deal, a green tick indicates that the Green Deal will cover the cost of the recommendation, an orange tick shows that the home owner will need to make an up-front contribution towards the cost of the improvement. The EPC also includes alternative measures. These are similar to the EPC recommendations but currently the cost of implementing them means they are not cost effective and are not available through the Green Deal. They are included in the EPC because they offer a significant reduction in CO 2 emissions, and may prompt the homeowner to investigate such options further. The EPC does not display the true cost or corresponding CO 2 savings of these measures. Assessors may remove recommendations from the EPC under specific circumstances, but it is not possible to add recommendations. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 11

12 1.3 PROPERTY DESCRIPTION Property Description This chapter will cover: Transaction Type Tenure Type Terrain Type Dwelling Type Built Form Detachment Flats and Maisonettes Heat loss corridors Floor position Floor exposure Roof type 12

13 Transaction Type An EPC must be assigned a transaction type. This information is used by Communities and Local Government (CLG) for analysis and is not displayed on the certificate. Marketed Sale Assigned to EPCs for properties which are marketed for sale Non-marketed Sale This is used for properties which are not advertised for sale, such as a transaction between family members Rental (Private) - This option is used for rental EPCs from the private sector Tenure Type Owner Occupied Household being assessed is occupied (lived in) by the current owner Rental (Social) Household is rented from a housing association or local authority Rental (Private) Household is rented from a private landlord or through an estate agent Unknown The household is empty or you are unable to find out the tenure Terrain Type 1.3 PROPERTY DESCRIPTION Rental (Social) - This option is used for dwellings owned by social landlords such as local authorities or housing associations Pre Green Deal Assessment - Used to produce an EPC before a Green Deal Assessment is carried out on the property Post Green Deal Assessment - Produced after the Green Deal Assessment in order to demonstrate changes in the property s energy efficiency FIT Application - This option is used when an occupier requires an EPC to apply for a Feed-in Tariff scheme, for example when installing Solar Photovoltaic Panels on their property None of the above - This option can be used if a property owner requires an EPC but regulations do not require it. For example, if a home-owner wants an EPC to find out how energy efficient their property is Terrain type is recorded in a survey to determine the average wind speed at the property, which can then be used to calculate the benefit of a wind turbine. If a property does not have a wind turbine, the terrain type must still be recorded in order to calculate the potential savings of installing the wind turbine for recommendations. Dense Urban - An area with closely spaced properties over 4 floors, generally city centres Low Rise Urban or Suburban - This usually relates to most properties in towns and cities, with several well spaced, neighbouring properties Rural - This refers to properties neighbouring areas of open land The wind turbine recommended by RdSAP has a 2m diameter rotor and a 2m hub height, so it is suitable to attach to the side of a property. Dwelling Type and Built Form All properties must be classified with a dwelling type. This information is displayed on the EPC and is sometimes used in the floor area calculations. Though the detachment of a flat is not shown on an EPC, it is still necessary to make a selection which describes the detachment of the flat as accurately as possible. The built form options are mostly self explanatory. Please Note: there is no technical distinction between a flat and a maisonette. We would advise that a flat is a single storey dwelling within a block of 2 or more floors, with a communal access corridor. A maisonette is a dwelling which occupies 2 or more floors within a block. It can also be described as a dwelling which has its own access directly from the outside (i.e. no communal corridor) but is not a standalone building. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 13

14 1.3 PROPERTY DESCRIPTION Detachment Detached These houses possess no party walls and thus have exposed wall area on all sides. Semi Detached - Semi-detached houses share one wall (the party wall) with a neighbour. This leaves at least three exposed walls. Mid Terrace - Mid-terrace houses have two party walls (one on either side) and two heat loss walls (front and back.) End Terrace - End of terrace properties have three exposed sides, like a semi-detached, but are at the end of a row. The software calculates a different glazing area for a semi-detached and end terrace house. An end-terrace property will usually have a blank gable end wall, where as a semi-detached house will most likely have additional glazing in the side elevation. Enclosed Mid Terrace - These houses are also known as back-to-backs. Back-to-back properties are essentially terraced houses split in half. They have only one heat loss wall, as the side walls are party walls to the neighbours and the rear wall is a party wall to a property at the rear. Flats and Maisonettes Technically there is no difference between a flat and a maisonette in RdSAP, the only difference is the description on the 1st page of the EPC. Stroma Certification uses the following definitions for these dwelling types as a guide to members: A flat is generally defined as a self contained residential unit within a larger structure, containing several self contained units or units all sharing a common entrance. They are usually single storey dwellings. A maisonette is a dwelling which occupies 2 or more floors within a block. It can also be described as a dwelling with its own access directly from the outside (i.e. no communal corridor) but is not a stand-alone building. When assessing a flat or maisonette, certain additional information will be required: Corridor type: Heated, unheated or no corridor Length of sheltered wall (if unheated corridor) Floor number Floor position Enclosed End Terrace - An enclosed end-terrace will be the first or last house in a terraced row of back-to-back houses. They have two heat loss walls to the front and side, and two party walls to the rear and side. Link Detached properties which are only linked to the neighbour by a garage should be classed as detached. Passage-ways between terraced properties - these do not affect the detachment of a property, though the length of the wall adjacent to the passage must be included in the Heat Loss Perimeter calculations. 14

15 Heat loss corridor Flats usually have common areas such as corridors, stairwells, lift shafts and lobbies. For the purposes of RdSAP, these are all classed as corridors. Record whether a corridor is heated or unheated. An unheated corridor is considered to be an exposed wall in RdSAP. The length of wall adjacent to the unheated corridor should be measured and recorded in the site notes, and included in the total heat loss perimeter for the flat. When a dwelling (flat or maisonette) has a sheltered wall to an unheated corridor on more than one storey the sheltered wall length is the total for all storeys with a sheltered wall. For example, 2 storeys with sheltered wall on each storey, the length of sheltered wall is 5m on each storey, the total sheltered wall length is 10m. Where a flat or maisonette has an unheated corridor, and the wall adjacent to it is of a different construction to the remainder of the dwelling, it is necessary to enter it as an alternative wall. For more information please refer to chapter 6 Property Elements. 1.3 PROPERTY DESCRIPTION A heated corridor is not a heat loss wall and does not need to be included in any heat loss calculations. For a more detailed explanation of calculating the corridor length and heat loss perimeter, refer to section Property Size. Floor number and Position Floor number The floor number is used to determine the exposure of the flat. The higher the flat is in a building, the more exposed it is to high wind speeds and heat losses from the dwelling are greater. The floor number refers to the lowest floor of the dwelling in relation to the building. The lowest floor of the building is always 0. When assessing the floor number non-habitable spaces, such as a car park or shop, should be included. The floor position can be selected from the following options: Top floor Mid floor Ground floor Basement The option selected is displayed on the front of the EPC The heat loss floor is specified in the floor construction section, see chapter 5 for more details. Roof Type Like all dwellings, a roof type must be selected for a flat/maisonette. The roof type refers specifically to the dwelling assessed, not the roof type for the whole block. For most ground and mid floor flats, the roof type will be another dwelling above indicating that there is a property above the flat, rather than a pitched or flat roof. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 15

16 1.3 PROPERTY DESCRIPTION Floor Number TOTAL FLOORS = 3 A Number of floors in block Floor Number TOTAL FLOORS = 6 B C SHOPS Number of floors in block Floor Number TOTAL FLOORS = 3 D BASEMENT FLATS Number of floors in block Flat A Software Entry Floor Exposure If a flat is on the ground floor it is not necessary to select the floor exposure. The software will assume it has heat loss to the ground only Flat B A flat located directly above another dwelling should be entered as not exposed. It is assumed a flat is heated, even if it is currently unoccupied, as it will not always be empty. Flat C A flat located directly above commercial premises should be entered as exposed to partially heated. The software accounts for some heating of the premises below, but not to the same extent or duration as the flat Flat D When a block of flats has a basement, investigate whether this is an occupied space. 16

17 1.4 PROPERTY AGE Property Age This chapter will cover: The characteristics of properties from pre 1900 to present day Is the age band important? Yes, the property age is used to determine the default U-values for the wall, roof and floor, and calculations for the window areas. Prior to the introduction of Building Regulations in the 1960s, age bands were used to determine the building materials, methods and typical U-values. Older age band properties will typically provide higher U-value ratings (meaning greater building heat loss) than newer properties. Conversions If a house has undergone a conversion which is a change of use (e.g. barn to dwelling) it must meet Building Regulations for the time of conversion. This means you can enter the age of the property as the conversion date (providing there is suitable documentary evidence to prove it has met building regulations). This does not apply to conversions where a dwelling has been sub-divided (e.g. a house split into flats) or refurbishments. In these cases the original construction date for the building should be used and retro-fit insulation can be added where there is physical or documentary evidence. In most cases, dwellings built at the beginning of an age band would have received building approval under the earlier age band regulations i.e. a building built in 1991 would fall into the regulation bracket. How to identify the age band of a property There are a number of ways to establish the age of a house: 1. Ask the occupants (this should be used as guidance only). 2. Building Regulations can provide clues for more modern houses. For example, the 1990 regulations introduced extract fans and trickle vents into windows. If the house does not possess these features it must belong to a pre age band. However, it is necessary to consider that windows may have been replaced in an older property with modern windows with trickle vents. 3. Look at the style characteristics of the building. Stylistic clues can be misleading, so try to take a few into consideration. Looking at the whole street is useful, rather than just the house being inspected. 4. Use documentary evidence. Maps of the area for older properties are available online. 5. Contact the local authority (this may take more time, but can give more accurate information) Age band England and Wales Northern Ireland Scotland A Pre 1900 Pre 1919 Pre 1919 B C D E F G H I J Not applicable K 2007 onwards 2007 onwards 2008 onwards For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 17

18 1.4 PROPERTY AGE Pre 1900 A mixture of styles ranging from Classical through to Gothic Covers a long period so there are many different fashions and influences Mid and late Victorian properties generally characterised by over ornamented features around doors, windows etc Use of local materials Most properties have chimneys, often large with several pots - however chimneys may have been removed Solid brick construction, sometimes rendered (wall thickness of about 220mm) Stone walls common, particularly in rural areas (wall thickness of mm) No damp proof course installed often retro-fitted damp proof course visible Early bricks are often narrower than modern bricks and of non-standard sizes Brick decoration between floors Stone lintels with some embellishment Original windows will be sash windows with small panes No car parking facilities, usually lots of cars parked on streets Old outbuildings sometimes present used to house outside toilet Internally, large houses had servant s quarters in the basement or attic 18

19 Whole streets developed at once, rather than the sporadic development of previous years 1.4 PROPERTY AGE More consistent in style Gothic arches and gables The use of larger panes of glass, due to a development in the manufacture of glass Mainly solid masonry (220mm thick walls) although the cavity (generally narrow, about 250mm thick) starts to be introduced in exposed regions of the country Tiled floor in porches Properties from this bracket tend to have the following characteristics: Larger property size Larger gardens Increased use of bay windows For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 19

20 1.4 PROPERTY AGE Rounded Bay windows designed to fit metal casement windows (nearly all now replaced) Cavity walls commonly used throughout the UK (about 250mm thick) Properties have damp proof course installed when built Detached garage or space for car Semi detached properties very common Hipped roofs rather than gable ended Still have chimneys Council house estates predominantly semi-detached and terraced properties. Any flats built are low-rise due to lack of lift technology Density of properties is increasing again Large growth of suburban estates Introduction of non-traditional (system build) buildings such as steel frame, timber frame, pre-cast and in-situ concrete 20

21 Typical characteristics of System Build Properties 1.4 PROPERTY AGE Pre-cast concrete panels are sometimes visible externally Today most systems built houses have had the external walls replaced or clad Concrete panels are visible in the loft space at gable ends Unusual wall thickness depending on type of system build For more detailed information about system build properties, please go to Chapter 4: Construction and Insulation For more information contact Stroma Certification at ext. 614 alternatively 21

22 1.4 PROPERTY AGE 1950s Council house building using traditional brick construction (about 250+mm thick), system build still used for some council properties Large numbers of system built council housing, particularly used for blocks of flats Large open plan estates not always clear boundaries between properties Bungalows are popular Flat roof porches Bay windows less common, still used on non-council houses Steel casement windows (usually replaced now) Chimney s still present on most properties until the 1960s, when gas boilers became more common Most properties now have a driveway and or garage Window openings increase in size and tend to be wider than they are high 22

23 1960s Brick cavity walls (about 250+mm thick), with some use of timber boarding, tile hanging or concrete panels for sections of properties 1.4 PROPERTY AGE Concrete roof coverings, slate rarely used Flat or low pitched roofs covered in roofing felt Introduction of brick and block cavity walls block work should be visible in the loft space at the gable end Open plan rooms, lounge/dining room Clean Air Act of 1956 greatly influenced the heating of dwellings and saw a reduction in properties with traditional chimneys. Solid fuels were rarely used New materials employed for construction, including plastic gutters to replace asbestos cement Cross wall construction became common, with masonry gable end and timber frame section in between, usually clad with tiles, timber or composite sheets. This allowed much more glazing to be incorporated than was previously possible Window areas are large and originally single glazed, with little consideration for heat loss due to the low price of oil Introduction of building regulations in Scotland in 1964, England and Wales 1966 and Northern Ireland in 1972 In 1961 the Parker Morris report was published. It imposed the following requirements on social housing in the UK: In one, two and three bedroom dwellings, one water closet is required (this may be in the bathroom) A semi-detached or end-of-terrace house for 4 people should have a net floor area of 72 m 2 A dwelling for three or more people should have enclosed storage space for the kitchen of 2.3 m 3 Dwellings should be fitted with heating systems that maintain the kitchen and circulation space at 13 o C, and the living and dining spaces at 18 C, when the external temperature is -1 C. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 23

24 1.4 PROPERTY AGE 1970s No chimneys or roof vents present for central heating Cavity walls measure about 260+mm thick Introduction of pre-fabricated trussed rafter roof from the mid 60s, extensively from 1970s Wider variety in built form, 2 and 3 storey houses, reacting to the sameness of 1960s design High walls and fences to enclose land, reacting to open-plan estates of the 1950s and 60s Increase in density of housing as the price of land increases also off plot car parking and much smaller gardens Soil stack is integral to building Cross wall construction still common, coloured panels used in front elevations Change in building regulation requirements for roof insulation (still less than a quarter of today) Flat roofs, mono pitch and shallow pitch roofs become popular, particularly in low cost housing developments Use of timber and steel frame construction is common The collapse of part of a concrete constructed block of flats (Ronan Point) in 1968 lead to the demolition of a number of similar style buildings with others undergoing substantial strengthening work Small amount of insulation assumed by RdSAP in roof and walls 1973 Oil Crisis The Yom Kippur war between Israel and Egypt saw oil suppliers treble their prices, which in turn increased the UK s awareness of the need for fuel efficiency. Building regulations started to make houses more energy efficient through the introduction of: Wall insulation Much smaller windows Double glazing 24

25 1980s Building design starts to come back 1.4 PROPERTY AGE Cavity walls measure about 270+mm thick Cul-de-sacs seen in housing estates Mixed styles in the same estate Reaction against high-rise flats leads to more low-rise developments Double glazing in dark wooden frames, often with curved window heads Chimneys start to reappear for gas flame effect fires Reduction in use of asbestos for external building materials i.e. soffits Enclosed front garden often with paved space for a car and integral garage Complicated roof shapes, occasionally with dormer windows Lines of different coloured bricks used to outline or connect windows and doors For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 25

26 1.4 PROPERTY AGE 1990s Often smaller plots, reducing the property footprint and garden area Different materials and the employment of slightly different styles in same development Cavity walls measure about mm thick Some floor insulation assumed by RdSAP from 1996 Often inclusion of some of the following features: Bay windows Mock pillars Porches Decorative brickwork Shared drives for several houses Small detached homes, narrow gaps between properties Studies, utility rooms, downstairs toilet and en-suite bathrooms become more common Introduction of trickle vents over windows Home owners more likely to know the actual date of construction Extractor fans in kitchen and bathroom(s) Allocated parking, driveways or garage 26

27 2000 to Present Day The owner/occupier is almost certain to know the original build date of the property 1.4 PROPERTY AGE Increased density of housing Encouraged development of Brownfield sites results in many post 2002 inner city developments High purchase and building cost mean 3 storey houses and rooms in roof become more common Timber frame construction is popular again Big developments with a few different property designs Weep holes above openings Soil stacks are built externally to the property Double glazing may have the date stamped in the bead Cavity wall thickness should be 300+mm For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 27

28 1.5 CONSTRUCTION AND INSULATION Construction and Insulation This chapter will cover: Wall construction Options in RdSAP Stone Brick Timber Frame System Build Cob Wall Wall Insulation Solid wall insulation Cavity wall insulation Roof Insulation Roof Construction Identifying the correct construction and insulation for the walls, roof and floor of a property is crucial to the production of an accurate EPC. The selected construction and insulation type defines the thermal characteristics (U-value) of a dwelling; for more modern properties this can be based on building regulations, for older properties assumptions are made based on the building techniques and materials available at the time. 28

29 What is a U-value? A U-value is the measure of the rate of heat loss from the building elements (wall, window, floor, roof etc). It is measured in W/m 2 K (Watts per metre squared per degree Kelvin). The higher the U-value of the house, the higher the rate of heat loss. This means that a property with a wall construction and high U-value will lose heat faster than a property with a low U-value. U-values vary between different construction materials, methods and age bands. In addition to this, retrofit insulation will improve the U-value of most elements, thus making it important to identify them correctly. Building Regulations now stipulate the required U-value of various building elements, which means that regardless of construction type, more modern properties (constructed after 2002) must meet a minimum U-value. Prior to this date U-values vary between different construction and insulation types. 1.5 CONSTRUCTION AND INSULATION For further guidance please read the Property Ageing section. Wall Construction RdSAP has the following wall construction options: Solid stone granite/whinstone Solid stone sandstone Solid brick Cob Cavity Timber frame System build Stone Wall This is a common construction type for older, rural properties, due to the proximity of local stone quarries and the difficulty in transporting heavy construction materials when the properties were built. Most solid stone properties were built Pre-1900, but there were some solid stone properties built in the early 1900s. These traditional stone built properties have a very poor U-value. The thickness of solid stone walls can vary significantly, so much so that there may be an impact on the U-value of the wall. In order to maintain a good level of accuracy in the survey the thickness of solid stone walls is measured and recorded, this allows RdSAP to adjust the U-values accordingly. The measurement must be between 0.10m and 1.5m. Typically a stone wall will measure at least 450mm. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 29

30 1.5 CONSTRUCTION AND INSULATION Brick Wall The most basic of brick walls are composed of courses of bricks laid end to end, known as stretcher bond. The thickness of this type of wall is the depth of 1 brick (112mm or 4 inches) and is known as a half-brick wall. Diagram 4.1 shows the stretcher bond and how it spreads the load across the whole wall. 75mm 225mm 112.5mm Diagram Half Brick Wall Single Brick Dimensions Solid Brick Walls Originally, buildings built from brick would have solid walls, rather than cavity construction. In order to provide adequate strength, a solid brick wall must be 215mm thick - known as a one brick thick wall. Stretcher bond is not suitable for these walls as there would be two half brick walls side by side with nothing tying them together, resulting in a weak construction. A number of different brick bonds were developed to overcome this problem, the two most common being English Bond and Flemish Bond. These bonds consist of bricks laid at right angles to tie the two halves of the wall together. As a result, a pattern of both headers and stretchers will be visible. A solid wall thickness of mm can be used to identify solid brick walls if the walls of the property are rendered. Diagram Cross section of a 1 brick thick solid wall Diagram English Bond Stretcher Header Diagram Flemish Bond There are a number of variations of the header and stretcher bonds including Garden Wall bonds. The Garden Wall bonds are considered to be weaker than the English and Flemish Bond but, given that they are used more frequently than the stretcher bond, they are considered easier to lay. Flemish garden wall bond English garden wall bond 30

31 Dry lining The option to enter dry lining in RSAP 9.91 only applies to stone and solid brick construction when as built or unknown has been selected as the insulation type. Dry lining is a type of internal lining that creates an air space behind it. Examples include plaster board on dabs, plasterboard on timber battens, and lath & plaster. Internal wall lining can usually be identified by using a basic tap test. Where a tap test is inconclusive and no other evidence is available, assume it is not dry lined. The air gap created by the dry lining improves the wall U-value and if identified this will result in a more accurate (and higher) SAP rating. N.B. Dry lining should not be confused with internal insulation. Insulation requires visual or documentary evidence as proof of its presence. 1.5 CONSTRUCTION AND INSULATION Cavity wall Cavity walls consist of two half brick walls (or 1 half brick and 1 block work wall) with a gap, or cavity, in between them. The inner and outer walls are joined together with wall ties. Early cavity walls used cast iron wall ties which are prone to corrosion, whereas more modern walls use stainless steel or plastic wall ties which are far more resistant. Early cavity walls possess a narrow cavity which often contains some building debris. This debris can form a bridge between the inner and outer wall and may result in damp problems. This said, cavities have increased in thickness over the years, as shown by the table below. Inner block work wall Stainless steel wall ties Half brick outer wall See later in this chapter for information about insulating cavity walls which are hard to treat. Pre onwards Typical cavity wall thickness* 250mm mm 270mm+ 300mm+ *This should only be used as a guide as wall thickness may vary throughout the country A cavity wall does not necessarily have to be made of brick; the inner wall can be pre-cast concrete with a brick outer wall, or a block work inner wall with a stone outer wall. The latter is commonly used in areas with traditional stone buildings to ensure that modern property is in keeping with its surroundings. Although it is not always immediately obvious that these walls are cavity walls, they usually measure 350mm thick and are considerably narrower than a traditional solid stone wall. This image shows the block work inner wall with a stone outer wall, leaving a cavity for insulation. This ensures the property will meet modern building regulations. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 31

32 1.5 CONSTRUCTION AND INSULATION Timber Frame Old timber frame buildings are often easy to identify due to their appearance; they have very poor thermal qualities, with quite narrow walls, often less than 200mm thick. Prior to WW2, a number of timber frame properties were built. Usually timber clad, they are easily identifiable as timber frame system builds. Post war saw a boom in timber frame construction, particularly in the 1960s and 70s (during which time Cross Wall construction also became popular). The timber frame properties of this period tend to be brick clad and are not easily distinguishable from other construction types of the era (with wall thicknesses of mm and increased thermal performance). During the 1980s the popularity of the timber frame construction dipped, with the majority of properties constructed from brick and block, but returned to favour in the 1990s. Modern Timber Frame Construction Modern timber frame properties are constructed using pre-fabricated panels with built in insulation, as well as water proof layers, fireproofing and soundproofing, plus plaster finish. There are a number of ways to identify a modern timber frame property from a brick cavity property: Tap the internal wall in a number of places timber frame walls sound hollow (dry lined walls also have this characteristic so additional evidence must be sought) Look in the loft space - you should be able to see timber frame or plasterboard over the gable end Modern timber frame properties are difficult to distinguish from cavity wall constructed properties as they are usually brick clad and similar in design to other construction types. The windows will be set back into the wall because they must sit within the timber frame and not the cladding. This means there should be a brick depth at the window when the property has been brick clad Look inside external meter cupboards, where it is sometimes possible to see the wall construction 32

33 System Build (non-traditional) Following the 2nd World War, a combination of the shortage of materials and skilled work force, plus the urgent need for additional housing, led to a number of alternative construction methods using concrete, steel and timber. System build properties can be quite easy to identify, if they have not undergone any additional work, as the original construction material is usually visible. However, many of these buildings will have had remedial work carried out to address defects in the construction. 1.5 CONSTRUCTION AND INSULATION The image shows an Airey house, built using pre-cast concrete panels. The neighbouring property, which has undergone remedial work, is now finished with brick. Other types of system build include in-situ concrete (Wimpey), steel frame (BISF), timber frame (Weir Timber). It is not necessary to identify the type of system build for RdSAP. Look for the following to identify system build properties: Wall Thickness tend to have unusual wall thicknesses, too narrow for solid wall but too thick for cavity wall Chimney large brick chimneys which usually look conspicuous on recently refurbished properties Neighbouring Properties some neighbours may not have had remedial work done Gable End Wall in Loft you should be able to see the wall construction at the gable end (concrete, steel, timber), even on properties which have had remedial work carried out Some system build properties which have undergone remedial work may need to be entered as a different build type, in order to accurately reflect the construction of the building. Many pre-cast concrete houses have had an external brick skin fitted with insulation between it and the original concrete wall. This can be entered as a cavity wall property in order to account for the cavity insulation. (RdSAP does not have an option for system build with cavity insulation). The date of remedial work can be used as the age band if sufficient work has been carried out to the whole property, and it can be confirmed that the work was performed to building regulations. Otherwise, revert to the original build date and enter the construction as cavity wall with filled cavity. Some system build types may have a small cavity. This build type should still be entered as system build to accurately reflect the U-value for the property. If there is evidence of retro-fitted cavity insulation to this type of system build, record as system build with internal insulation. Window sizes tend to be non-standard designed to fit between concrete panels Usually located in clusters it is rare to find single developments of system build houses For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 33

34 1.5 CONSTRUCTION AND INSULATION Cob Wall Cob walls employ a traditional construction method found mainly in Devon and Somerset. They are constructed from layers of mud mixed with straw, which leads to their characteristic rounded and uneven finish. Cob Walls are often rendered to improve weatherproofing and are likely to have a wall thickness of at least 500mm, though this may vary significantly on older properties. Modern Cob Wall constructions should have a thickness in excess of 550mm, in order to meet building regulations. Key Ways to Identify Wall Construction Build type Wall thickness Appearance Age range Other key features Solid stone wall 450mm + Stone Up to early 1900s Solid brick wall mm Header-stretcher Up to 1935 bond Cavity wall mm Stretcher bond Early 1900s Sometimes evidence of cavity onwards insulation drill holes Timber frame mm Brick, tile or All (unlikely in Brick reveal at windows, timber cladding, 1980s) tapping walls results in a rendered hollow sound, timber is visible at gable System build mm Concrete panels, Concrete, timber or no remedial steel or timber steel visible at gable work cladding System build 300mm + Stretcher bond May be deep reveal at remedial work brick work or window carried out rendered Unusual window sizes Cob wall 500mm+ White wash or Mostly Pre Often thatched roof rendered 1900, some Rounded finish post 2000 to walls It is now very important to take a measurement of the wall thickness. This helps to get a more accurate U-value. Manual U-value Entry If the U-value data is available for a dwelling, rather than specifying the type and amount of wall insulation, RdSAP has the facility to enter the U-value, over-writing the assumed values. In order to do this there MUST be documentary evidence available; DEAs should not enter approximate or acquired U-values. The U-values must fall in the range If the U-value is entered into the software it is not possible to specify any insulation. 34

35 Wall Insulation Insulating Solid Walls Internal or external insulation can be fitted to solid walls made of brick or stone, and can also be found on Cob, System Build, some Cavity and Timber Frame Constructions. External Insulation This is usually installed in the form of insulation boards fixed to the outside wall, finished with render. Can be identified by a deep reveal at the windows and an 8-10cm step to the original brick work at the bottom of the render. (A property which has been rendered without insulation will have a step of approx 3cm). Internal Insulation Please ensure you are fully satisfied that a wall has been insulated prior to its inclusion in the RdSAP software, as details of insulation are clearly identified on the final EPC. A render or dry lined wall can not be counted as insulation. Unknown Insulation When the Unknown option is selected for wall insulation, any recommendation to insulate the wall is suppressed. If there is no evidence of retro-fitted insulation, then as built should be selected. Unknown Insulation should only be used in exceptional circumstances. For example, where documentary evidence and physical evidence provide conflicting information, please make sure this is clearly recorded in the site notes. 1.5 CONSTRUCTION AND INSULATION In order to install internal insulation, timber battens are fitted to the internal walls of a dwelling. Insulation is placed between the battens and then covered with plasterboard. example of property with external insulation Plasterboard Timber batten Insulation between timber battens Dry lining Solid brick wall diagram of internal insulation It can be difficult to identify internal insulation, and ideally documentary evidence should be sought. Otherwise you must be able to confirm that insulation is present by observing the insulation and gathering photographic evidence. It will not always be possible to do this as the insulation will usually be behind plasterboard. If this is the case then the insulation cannot be included. Internal and external insulation thickness Where possible the thickness of solid wall insulation should be measured and recorded. Internal and external insulation can be entered into RdSAP as 50/100/150mm. If the insulation thickness cannot be measured then specify unknown and RdSAP will assume 50mm thickness. Some properties are dry lined, this means the external walls have plasterboard fitted, usually to provided an even and straight finish to the walls. Dry lining can offer significant improvement to the U-value of solid stone and solid brick walls, and therefore can be recorded for such wall types in RdSAP. Walls can be dry lined using one of the following techniques: Dot and dab - small amounts of plaster/adhesive are applied to the wall at regular intervals and plasterboard is fixed to the wall by the adhesive dabs. Battens - timber battens are fixed to the wall to form a framework, the plasterboard is fixed to this framework. Metal track - very similar to the timber battens, a metal framework is fixed to the wall and the plasterboard is fixed to this. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 35

36 1.5 CONSTRUCTION AND INSULATION Cavity insulation Until recent years, cavity walls had either partial or no insulation fitted at the time of construction and may consequently have had retro-fit insulation installed. Retro-fit cavity insulation is identified by the drill holes at mortar joints in the brick work where the insulation has been injected into the cavity. The drill holes are usually in a specific pattern to ensure the cavity is completely filled, leaving no cold, uninsulated patches. Selecting filled cavity in RdSAP will assume the insulation is retro-fitted. Selecting as built will apply the insulation installed when the property was constructed. When surveying a modern cavity wall property you must select as built unless there is physical evidence that additional insulation has been installed. Insulation being pumped into the cavity Cavity fill drill hole with insulation visible Other ways to identify cavity wall insulation: Overspill of insulation in the loft and/or meter boxes Guarantee certificate held by home-owner Cavity fill drill hole with mortar Be careful not to confuse cavity wall insulation drill holes with drill holes for replacement wall ties. These drill holes are always in the centre of a brick, rather than a mortar joint. Because cavity wall insulation has a significant effect on the energy rating, it is important to make every effort to check that cavity wall insulation is present. If there is any uncertainty regarding the presence of insulation, this should be recorded as built or unknown rather than filled cavity. For each of these choices the energy rating will be altered in line with RdSAP methodology. This approach ensures that cavity wall insulation is recommended if it is a cost-effective improvement to the property. The EPC suggests contacting a reputable cavity wall installer to check that the property is suitable prior to any work being carried out. 36

37 Some walls are not suited to retrofit cavity insulation: Limited access - where it isn t feasible for the installers to access the external walls of a property, e.g. narrow passageway, busy thoroughfare, large conservatory attached to property. These issues can increase the cost of installation. Narrow cavity (finger cavity) - where the cavity is too narrow for standard blown cavity insulation, indicated by a stretcher bond pattern with wall thickness of mm. Likely to be early cavity construction properties built before the 1940s. 1.5 CONSTRUCTION AND INSULATION High exposure - properties located in exposed areas are more prone to wind driven rain, filling the cavity can lead to damp issues. This applies to any property located in exposure zones 3 and 4 (blue areas on the map) There are addenda in RdSAP which should be included in the EPC should any of these situations apply to the dwelling surveyed. Roof Construction Roof identification should be straight forward for most properties. The roof construction option relates to the top most floor of the dwelling surveyed. When assessing a flat or maisonette the roof type should reflect the heat loss from the property assessed. Roof type Pitched (slates or tiles) access to loft Pitched (slates or tiles) no access to loft Pitched (thatched) Flat roof Another dwelling above Same dwelling above Option can be used for following property type House, bungalow, top floor flat/maisonette House, bungalow, top floor flat/maisonette House, bungalow, top floor flat/maisonette House, bungalow, top floor flat/maisonette Mid floor flat, ground floor flat, basement flat or an extension to a house or bungalow Mid floor flat, ground floor flat, basement flat or an extension to a house or bungalow Description Any type of pitched roof where the loft space can be accessed Any type of pitched roof where there is no access to the loft, this may be because the loft hatch has been sealed, or it is too dangerous to access Any type of pitched roof which is thatched. The software will assume some insulation is provided by the thatch A flat roof should have a slope of less than 10 degrees This option relates to the space above the top floor of the dwelling assessed. Often used for ground and mid floor flats in a block. May also be used for under-dwellings and extensions underneath another property. This option relates to the space above the top floor of the dwelling assessed. It can be used when a property has an extension above an existing part of the dwelling. For more details on how to use the floor and roof types for vertical extensions please see the section Property Elements For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 37

38 1.5 CONSTRUCTION ANS INSULATION Pitched Roof Insulation If there is access to the loft and the insulation is located at joists or rafters, the insulation thickness should be measured where possible. If the insulation cannot be accessed then select unknown, RdSAP will assume the insulation thickness based on the property age. RdSAP bases insulation depths on mineral wool insulation. Foil/Foam insulation If the property has modern foil or foam insulation at joists the depth of the insulation is entered as double its actual thickness. Variable insulation thickness If the insulation depth varies across the loft, the average depth should be recorded. Unless there is no insulation to part of the loft, in which case the property should be split into main house and extension to allow for the different roof insulation depth. This is because the heat loss through zero insulation is significantly greater than it is through even 12mm of insulation and to average the insulation thickness would not accurately reflect the heat losses for the property. Insulation at joists and rafters If loft insulation is present at both joists and rafters then record the joist insulation only. Do not add the thickness of the rafter insulation to the joist insulation. Unknown loft insulation If the loft is boarded and there is no way of viewing the loft insulation, unknown should be selected. If a loft is partially boarded then assess whether you can see more than 50% of the loft area and, if this is the case, record the depth of insulation. If you cannot assess more than 50% then you can either split the property into main house and extension to account for the different insulation levels, or record unknown for the whole loft. Flat Roof Insulation It is not possible to measure flat roof insulation in the same way as pitched roof insulation. The It is not always possible to measure flat roof insulation in the same way as pitched roof insulation. The options for flat roof insulation are: None if you know there is no insulation present Flat Roof Insulation - use this option if there is evidence, either visual or documentary, to prove that insulation has been retrofitted this option does not need to be selected for a modern property as RdSAP will assume insulation is installed to meet building regulations. Unknown - if the insulation cannot be measured but there is documentary evidence it is installed, RdSAP will assume 50mm of insulation. 50mm, 100mm or 150mm or more these thicknesses can be specified if the flat roof insulation can be accessed and measured Unknown - this option will be selected in most cases as it is unusual to have access to flat roof insulation. No access to loft If there is no access to the loft then select Pitched, no access and unknown for insulation level unless the home-owner/occupier can supply suitable evidence to confirm the level of insulation. Suitable evidence would be a certificate from insulation fitters or an invoice specifically stating the work was carried out at the property and the level of insulation fitted. 38

39 Floor Construction and Insulation There are four options for floor construction: Unknown Solid Suspended, timber Suspended, not timber Floor insulation options are limited to: Unknown this option should be selected If you are unsure about the level of insulation, which is likely in most cases. This option assumes insulation levels based on the age band selected for the property As Built this confirms that the floor insulation remains as it was when originally installed. This option assumes insulation levels based on the age band selected for the property 1.5 CONSTRUCTION AND INSULATION Retro-fitted this option should only be selected if insulation is present and can be confirmed by DEA observation or documentary evidence such as a guarantee certificate If the surveyed dwelling has another dwelling below there is no need to select the floor insulation as the floor is not considered a heat loss surface. Non timber suspended floor There are a few ways to identify floor construction. Look under ground floor coverings (e.g. carpet) which are not fixed down to see the floor surface. The presence of air vents in external walls, just above ground level, is an indication of suspended floors. The floor heat loss type refers to the lowest floor of the dwelling, the following options are available: Lowest floor heat loss type Ground floor Above partially/intermittently heated space Above unheated space To external air Same dwelling below Another dwelling below Description when the lowest floor of the dwelling is on the ground when the lowest floor is above a non-domestic premises. This is classed as partially heated because non-domestic dwellings are assumed to have a different heating pattern to dwellings. when the lowest floor is above a space not used for habitation e.g. Garage when the lowest floor is exposed to the outside When the lowest floor is above part of the same dwelling, this can be used when a property has an extension above an existing part of the dwelling The lowest floor of the dwelling is above another dwelling. This option is often used for mid and top floor flats, but can be used for under dwellings and extensions over another property (flying freehold) For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 39

40 1.6 PROPERTY ELEMENTS Property Elements This chapter covers: Extensions Identification, Multiple extensions, Extension over a garage, Vertical Extensions Alternative Walls Porches Basements Room in a Roof Identification, Measuring, Insulation Mezzanine Floors Conservatories Identification, Measuring, Sun Rooms Windows Ventilation Fireplace Count Mechanical Ventilation Lighting 40

41 Extensions For the purposes of RdSAP an extension is part of a property which has different thermal qualities to the rest of the house. This can be due to: Age Wall construction/insulation type Roof construction/insulation type Floor heat loss type Sometimes it is necessary to record part of a property as an extension in order to account for significantly different ceiling heights in a dwelling. It may also be necessary to enter an extension if a property has a typical 2 storey area and a single storey with room in roof. By splitting the property into main house and extension the property can be more accurately modelled. As with the main property, information regarding construction, roof type, floor construction, insulation, area and HLP must be recorded for all extensions. The Stroma site notes and software have specific sections for this data to be recorded. Multiple Extensions RdSAP allows for 4 extensions, which is generally enough for the majority of properties. It is unusual to come across a house which has more than 4 extensions, but in this situation you must blend the extensions, merging the areas with the most similar construction and insulation, making use of the alternative wall facility where appropriate. Extension Above a Garage If a property has an extension over an unheated garage or similar unheated space, it should be entered as an extension on the lowest floor as the garage is not included in the survey. You should specify the floor type as above an unheated space, this will indicate to the software that the extension is over the garage and not on the ground. If the garage is heated by the main system it should be included in the assessment, so the extension over the garage should be specified as over the same dwelling. 1.6 PROPERTY ELEMENTS Vertical Extensions A vertical extension is an additional storey to a property which cannot be accounted for as a room in the roof. In the example the original property is a 2 storey building (the main property) with a single storey section to the rear (Extension 1). A new extension has been added on top of the single storey part of the building. In order to reflect the new part of the property it must be identified as an extension, with the appropriate age band. The floor and roof types available in RdSAP allow you to indicate that the new extension is above the existing property by selecting same dwelling below for floor heat loss type. It is also possible to indicate that extension 1 has the extension above it by selecting same dwelling above for roof type. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 41

42 1.6 PROPERTY ELEMENTS Alternative Wall An alternative wall should be used to record an area of a property which can not be accounted for as an extension, but which is thermally different due to a different construction type or insulation. It must make up a minimum of 10% of the external wall area of the specific building part (main property, extension 1, etc). Areas smaller than this can be accounted for as part of the main wall unless there is specific documentary or visual evidence of retrofitted insulation. The area of any windows and doors should be excluded from the alternative wall area. Please record the following information: Construction type Insulation type Insulation thickness (if available) Wall thickness Please note, the alternative wall should always be smaller than the main wall area. Don t forget that the main wall area will have the window area subtracted from it by the RdSAP software. You can quickly calculate the main wall area by multiplying the heat loss perimeter by the ceiling height for each storey. You can calculate the window area using windows table later in this chapter. Unheated corridors Where a flat or maisonette has an unheated corridor it is necessary to assess the construction of the wall adjacent to the unheated corridor (also known as the sheltered wall). If it is different to the main wall construction then this wall must be entered as an alternative wall to allow RdSAP to calculate the heat loss accurately. When an unheated corridor is specified in the software it is possible to select sheltered wall as the alternative wall location. Wall U-value (if available) Location i.e. main building or extension Area calculations Photographic evidence Common alternative walls include: Bay windows when on both ground and first floor Stone walls with thickness varying by more than 100mm in the same building part Timber frame section on cross construction property Properties where the construction of different floors varies There is no need to identify the following as alternative walls: Stud walls in rooms in the roof Wall between house and an unheated garage Dormer cheeks Porches Porches can be internal or external to the property. Internal porches are located inside the line of the external wall of the property; an external porch would protrude from the external wall of the property.. If a porch is heated by fixed heaters it should be included If a porch is external and not heated by fixed heaters it should be excluded If a porch is internal, not heated and thermally separated from the dwelling it should be excluded Please ensure any walls adjacent to an unheated separated porch are included in the HLP calculations. 42

43 Basements A basement is defined as a storey with 50% or more of its external walls adjacent to soil. To be included in the survey the basement must: Be accessed via a permanent fixed staircase that one is able to walk up and down facing forwards 1.6 PROPERTY ELEMENTS Be heated by fixed heaters and/or open to the rest of the dwelling ROOF SPACE ROOM IN ROOF FIRST FLOOR FIRST FLOOR GROUND FLOOR GROUND FLOOR UNHEATED BASEMENT/CELLAR HEATED BASEMENT/CELLAR 2 Storey House 4 Storey House If the basement meets these criteria the dimensions are entered as the lowest floor on the Age and Dimensions section of the software. Include any walls adjacent to soil in the HLP calculations. Please Note: a basement does not have to include habitable rooms to be included in the survey. When assessing a property with a basement it is likely that the measurements will have to be taken internally for the basement. Therefore internal measurements should be used for the whole dwelling. If the store/utility room is heated If the store/utility room is accessible only via a separate external door and is not heated If the store/utility room is directly accessible from the dwelling, not heated and thermally separated Include in assessment Do not Include in assessment Do not Include in assessment Garages If a garage is heated by the main heating system it should be included in the assessment. Please note the presence of a boiler in a garage does not make it heated. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 43

44 1.6 PROPERTY ELEMENTS Room in Roof A room in a roof is defined by the following: Access must be via a permanent fixed staircase that one is able to walk up and down facing forwards (This does not include fixed loft ladders). The height of the common wall must be less than 1.8m for at least 50% of the storey. Please note this does not include stud walls, gable ends or party walls. (The common wall is a vertical continuation of the external wall of the storey below.) If the common wall measures greater than 1.8m for at least 50% of the common wall then it is classed as a normal storey. Different Types of Room in Roof: Loft conversion Dorma bungalow/chalet bungalow Original storey with common wall less than 1.8m Ignore height of stud wall common wall less than 1.8m 44

45 Measuring Rooms in Roof Measure from stud wall to stud wall (do not include the thickness of the stud) 1.6 PROPERTY ELEMENTS The eaves space behind the stud is classed as non habitable space and should not be included in the area calculation. Stud partition Include floor area of dorma windows No need to measure the HLP and the ceiling height as they are both defaulted by the RdSAP software You must always measure a room in roof internally Measurements for a room in roof must always be made internally 3.84m Non habitable space It is possible to overwrite some of the assumptions made by RdSAP about roof rooms, including the area and U-value of the flat ceiling, gable wall, stud wall and sloped wall. This is particularly useful when the level of insulation differs at different parts of the roof room By clicking 'edit roof room' in the software this data can be entered manually. The U-value must be available and from an approved source There can be up to 2 of each of the roof room parts Please note the convention specific to roof room measurements: Detailed measurements of roof rooms are required only if evidence exists that the slope, stud wall (or common wall) or gable wall have differing levels of insulation and each of their U-values is known. If all elements of the roof room (slope/stud/gable) have the same insulation and the U-value is available, the U-value can be overwritten whilst leaving the RdSAP assumed areas as is. Where detailed measurements are made and the floor area of the parts of the dormer windows protruding beyond the roof line is less than 20% of the floor area of the roof room, measure the elements of the roof room as if the dormers were not there. Otherwise total the vertical elements of all dormers in that building part and enter as stud wall and the flat ceiling elements as flat ceiling. A roof room is indicated as connected if it is adjacent to (i.e. at the same level as) another building part of the same dwelling (which can be either a roof room or a normal storey). Room in Roof Age You are required to enter an age band for the room in a roof. The date selected influences the level of insulation assumed if there is no access. The age band for a room in roof may be different to that of the main property. If the loft has been converted it may not be possible to ascertain evidence of the conversion date, the original build date of the property should be used. A room in a roof does not only apply to a loft conversion it may be part of the original build. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 45

46 1.6 PROPERTY ELEMENTS Room in Roof Insulation Main Roof Insulation When room in the roof is selected you still have the option to enter the roof insulation for the main part of the building. This is the insulation located either side of the room in roof, often behind the stud walls, shown in red. It is not always possible to gain access to this area, in which case unknown should be selected. No Insulation No insulation at the rafters, joists or flat ceiling element. It is assumed that older properties will not have roof insulation. Flat Ceiling Only Insulation located in the flat ceiling only In some cases there will be access to a small loft space, from which you can see if insulation is located in the loft All Elements with Flat Ceiling The insulation is located in the ceiling and in between the purlin supports. You can select the insulation thickness at the flat ceiling in the software, the insulation to the sloping sections or stud walls of the room in roof can also be specified as 50, 100 or 150mm thick or unknown. The thickness can only be specified if you have physical or documentary evidence that the insulation is present. If you are not able to see the insulation enter unknown; the software will then assume insulation based on the room in roof age. Insulation layer All Elements Vaulted Ceiling For a room in roof with a vaulted ceiling, if you can confirm there is insulation present, select all elements for location and not applicable for thickness, the thickness only applies when there is a flat ceiling, as above. Unknown Insulation In most cases the amount of insulation will not be visible. In this case entering unknown insulation would be the correct option. Unknown insulation will use the default U-values for the age band selected. 46

47 Flats in the Roof If a single storey flat is located entirely in the roof it cannot be entered as a room in a roof: 1.6 PROPERTY ELEMENTS Enter the wall construction as timber frame The ceiling height should be entered as 2.2m Enter any masonry external walls as an alternative wall Room in Roof Over an Un-heated Garage When a room in roof is located over an unheated garage or similar unheated space, it should be entered as an extension on the lowest floor as the garage is not included in the survey. The floor heat loss type should be identified as over an unheated space. The wall construction is entered as timber frame and the ceiling height 2.2m. Please Note: if the garage is heated by the main heating system, it should be included in the area and HLP calculations of the main property. Mezzanine Floors A mezzanine floor is usually an intermediate floor, located between 2 floors in a building, although this is not always the case. They are often installed to maximise the use of space in a property. They do not extend across the whole of a floor, which means part of the property has a double height ceiling. When assessing a property with a mezzanine split the dwelling into main property and extension. Enter the 2 storey section as an extension; the single storey section can be entered with the full room height. If the mezzanine level is not located next to any heat loss walls then a nominal 1 metre perimeter should be assigned to the mezzanine level, this 1 metre should be deducted from the actual HLP for the property. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 47

48 1.6 PROPERTY ELEMENTS Conservatories A conservatory is defined as a structure with at least 75% glazed roof and 50% glazed external walls. If these requirements are not met the structure should be included in the survey as an extension (see Windows for explanation of how to enter this into a survey) Is the conservatory separated or non-separated? Separated the conservatory is separated from the property by an external quality door. If the conservatory is separated from the dwelling then it is not necessary to take measurements of the conservatory the only information recorded is whether it is fitted with fixed heaters. Non-separated either the conservatory is open to the property or separated by an internal quality door. A non-separated conservatory requires the following data to be collected: Floor area MAIN DWELLING PROPERTY 1 Exposed perimeter Type of glazing e.g. double glazed Storey height measured in half storeys relative to the main dwelling 3 NON-SEPARATED CONSERVATORY For property 1, the following should be recorded in the conservatory section: 5 Floor area - 15m 2 Exposed perimeter 11m MAIN DWELLING PROPERTY 2 Double glazing 1 storey high The heat loss perimeter for a property with a separated conservatory should include the length of wall next to the conservatory. SEPARATED CONSERVATORY Heat Loss Perimeter If the conservatory is non-separated then the heat loss perimeter for the main house should not include the length of wall next to the conservatory, as shown in the floor plan. Exposed Perimeter Remember, the conservatory floor area and exposed perimeter are not included in the area and heat loss perimeter figures for the dwelling 48

49 Sunrooms A conservatory is defined as a structure with at least 75% glazed roof and 50% glazed external walls. If these requirements are not met the structure should be included in the survey as an extension, this part of the dwelling is sometimes referred to as a sun room. 1.6 PROPERTY ELEMENTS If the sun room has a glazed roof select more than typical glazing in the window section of the software. This will enable you to enter the roof area as glazed, but will also require the area of all other windows in the property to be entered. This can be done based on the RdSAP assumptions (see table 1) if the property has typical glazing. Please Note: it will still be necessary to enter roof construction details for the extension, flat roof, no insulation is usually the most applicable. If the sunroom roof is a typical pitched or flat roof construction, but there is a significant window area it is necessary to select much more than typical glazing in the window section of the software. This will enable you to enter the additional window area in the sun room, but will also require the area of all other windows in the property to be entered. This can be done based on the RdSAP assumptions (see table 1) if the property has typical glazing. Doors Some modern external doors are highly insulated offering much improved thermal resistance to traditional, uninsulated doors. In order to account for these doors the following must be recorded: Number of external doors (a door to a heated corridor is not included in the external door count) Number of insulated external doors U-value of insulated doors In order to specify a door as insulated there must be documentary evidence including the U-value or manufacturer reference enabling the assessor to ascertain the U-value from the manufacturer. If there is more than one insulated door, and the U-values differ between those doors, enter the average U-value For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 49

50 1.6 PROPERTY ELEMENTS Windows When assessing windows the whole property is considered, there is no facility to separate the glazing for main house and any extensions. There are 3 features of the windows in a dwelling which must be recorded: Window area Percentage multiple glazed Type of glazing Please Note: conservatory glazing should not be included in this section, they are dealt with entirely in the conservatory element of the survey. Window Area It is not usually necessary to measure all the windows in a property; RdSAP has default values for window area based on the age band selected for main part of the dwelling, as shown in Table 1. TABLE 1 Age band of To calculate window area To calculate window area main dwelling for a House or Bungalow for a Flat or Maisonette A, B,C x TFA x TFA D x TFA x TFA E x TFA x TFA F x TFA x TFA G x TFA x TFA H x TFA x TFA I x TFA x TFA J, K x TFA x TFA TFA = total floor area of main part plus any extension Window area is assessed as one of the following categories: Typical window area representative of typical property in the age band selected for the dwelling. Please Note: although a property may originally have been constructed with significant areas of window, this may not be typical of the age band. Less than typical/more than typical there have been some alterations to the windows in the property which increase or decrease the typical window area. Usually the addition of large patio doors or a sun room. Much less than typical/much more than typical this option indicates the window area is significantly different to that expected for a property of the selected age band; such as a property with a fully glazed wall or a Huff Haus. The assessor must take measurements of all windows in the property, rather than using RdSAP assumptions. In the software, when much more or much less than typical is selected, the extended window data will be enabled and specific window information is added. In this case the assessor must record the window area, the glazing type, the orientation of the window, and its location in the building. 50

51 Percentage Multiple Glazed This is a calculation of the proportion of total window area which is double or triple glazed. This should include any windows which have permanent secondary glazing fitted, temporary secondary glazing, such as cling film, should be discounted from this calculation. Please Note: that this calculation is based on total window area and not the number of windows. Some post 2002 windows have an air gap of +12mm, although more modern units injected with gas may have a narrower gap Date stamp of 2002 or later on the metal strip inside the glazing unit or window frame: 1.6 PROPERTY ELEMENTS When entering the percentage into the software, if the figure is less than 100% the remaining percentage is assumed to be single glazing, 0% will indicate the property is fully single glazed. The U-Value and g-value can be recorded for windows where sufficient documentary evidence is available, such as a Window Energy Rating Certificate (as defined by the BFRC) or manufacturer s data. The U-Value is for the whole window, including the window frame. The g-value relates to just the glass, and is a measure of transmittance or the amount of sunlight the glass lets through. Typically a g-value will be between Identifying the Glazing Type The types of multiple glazing which can be selected are: Double glazed pre 2002 Double glazed post 2002 Double glazed unknown Secondary glazing Triple glazing Only one glazing type can be selected from this list, if more than one type is present at a property the most prevalent type should be selected. For example, a property had double glazing installed in 1998, in 2004 they had 2 small units replaced, the majority of the windows are still pre 2002, and this option should be selected in the software. Double glazing can be entered as units installed before 2002 or after The 2002 building regulations introduced a minimum standard which double glazed units must comply with when installed, this is indicated in a number of ways. Presence of gas fill indicated by drill holes in the air gap Presence of low-e coating identifiable with a low-e detector A FENSA certificate held by the owner/occupier. The FENSA website also holds details of properties with certified windows Earlier double glazing has a more narrow air gap, less than 12mm. If it is not possible to identify the date of installation then the glazing should be entered as pre Secondary glazing should only be accounted for in a survey if units are installed correctly. Temporary additional glazing, such as cling film, should not be included in the survey. If the secondary glazing has been temporarily removed then confirm that the panels are still present at the property and can be re-fitted. Triple glazing can be identified by 3 panes of glass with 2 separate air gaps within the unit. The glazed unit will look quite wide in comparison with a standard double glazed unit. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 51

52 1.6 PROPERTY ELEMENTS Draught Proofing It is necessary to assess the extent of draught proofing to doors and windows in a dwelling. At least 2 windows per building part and all external doors should be checked for the presence of draught proofing. Include glazing in a non-separated conservatory. Where a window is locked or inaccessible then check an alternative window Calculate the percentage of draught proofing as: [(number of draught proofed windows and doors) divided by (total number of windows and doors)] x 100 for example a dwelling has 2 doors which aren't draught proofed and 8 windows, of which 7 are draught proofed: (7/10) x 100 = 70% Open the window to look at the draught proofing around the edge of the window. If it is not possible to open any windows to view the draught proofing then assume that triple, double and secondary glazing is draught proofed and single glazed doors and windows are not draught proofed. Ventilation Open Fire Places Fireplaces must be identified in a survey for two purposes: Their impact on ventilation in the property They may be considered part of heating system in property The open fireplace count is purely to determine their effect on ventilation in the property; the heating application is covered in the Space Heating chapter of this manual. Fireplaces should be recorded in the survey if they are open to the chimney. Do not include any of the following: A fireplace with an open flue less than 200mm in diameter A permanently blocked fireplace a fireplace blocked with cardboard, newspaper etc is considered temporary, these fireplaces should still be included in the survey A fireplace fitted with a heating appliance which controls air flow. i.e. closing doors A fireplace fitted with a flued appliance such as gas fire or log burning stove A chimney which is sealed using a flexible gas flue liner Mechanical Ventilation Mechanical ventilation applies to whole house ventilation systems only, intermittent extract fans, often located in kitchens and bathrooms are not considered mechanical ventilation in RdSAP. Continuously running extract fans in wet rooms are treated as mechanical extract ventilation; extract only should be selected in the software. A balanced system would extract warm, damp air from rooms such as the bathroom and kitchen and, using a heat exchanger, supply remaining rooms with clean air. Such a system would usually have a central unit and ducting located in the loft or a cupboard and extract or supply vents in most rooms in the property. A chimney fitted with a damper which can be closed when the fireplace is not in use 52

53 Lighting The assessment of the proportion of low energy lighting in a property should only include fixed outlets. Any lighting which can be removed, such as a desk lamp, is not included in the assessment. 1.6 PROPERTY ELEMENTS Individual fittings only count as one in the lighting count, even if they hold several bulbs. Recessed spot lights and multiple halogen bulb fittings, often found in kitchens, are usually on a single low voltage circuit. There are often large numbers of these lights; in order to avoid skewing the lighting count if there are more than 4 down lighters the number of spot lights should be divided by 2. Any under cupboard lighting in a kitchen should be included in the count. Lights fitted in the following should not be included in the lighting count: cupboards loft spaces separated conservatories porches not included in the survey unheated garages outside lighting It is not always possible to view the bulb in a light fitting, particularly the 2D fittings. If possible switch the light on as a delay in the bulb lighting up indicates it is likely to be energy saving. Please Note: halogen bulbs although on a low voltage system, are not considered to be low energy lighting in RdSAP. The software will calculate the percentage of low energy lighting. This will be based on: The following are all counted as low energy bulbs: Compact fluorescent Fluorescent tube LED spot lights The total number of light fittings and; The total with low energy lights fitted. This should be collected on site and recorded in the software lighting section. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 53

54 1.7 PROPERTY SIZE Property Size This chapter covers: How to calculate Wall thickness Floor area Heat loss perimeter Ceiling height Habitable room count Measurement of bay windows Wall Thickness Wall thickness must be measured in mm at each external wall and any alternative wall, they can be measured at doors, or window reveals. Wall thickness measurements must fall between 50 and 1500mm ( m) to be accepted by the software. Where a wall thickness varies for a building part calculate a weighted average. For example, a detached house with all four sides of equal length, the rear wall being 250mm thick; and the remaining walls being 350mm thick. The average thickness is calculated as follows: (0.25 x 250) + (0.75 x 350) = 325mm The preference is to measure the wall thickness across a window or door reveal but this is not always possible. Where it is not possible, carry out an internal/external measurement comparison where the internal measurement is subtracted from the external measurement to give the wall thickness. The wall thickness will be used to determine the U-value of solid stone walls built before 1975 (1977 in Northern Ireland). Wall thickness is used by RdSAP to calculate the floor area of a property where external measurements have been used. 54

55 Building Dimensions Building Dimensions are an important element of determining the energy usage for a dwelling. The 4 main dimensions required are: Floor area Heat loss perimeter Ceiling height Wall thickness Heat Loss Perimeter The heat loss perimeter is a linear measurement for each floor of a property, meaning all exposed walls must be included. An exposed wall is an external wall to a property and also includes the length of any wall adjacent to: an unheated corridor a lift shaft a separated conservatory an unheated garage 1.7 PROPERTY SIZE All measurements should be recorded to at least 1 decimal place (0.1m), except when measuring ceiling heights which should be to 2 decimal places (0.01m). Floor Area The floor area is calculated separately for each storey of a dwelling and should include all rooms and other spaces, such as built-in cupboards which are accessed directly from within the dwelling. Projections such as bay windows should be included in the floor area; chimney breasts can be ignored unless significant in size. The floor area should not include the following: Unheated garage Store rooms accessed by a separate external door Separated conservatories Unheated/separated basement Roof space (which is not classed as a Room in Roof) Unheated porch Soil (when assessing basements) When assessing a flat, the length of the wall adjacent to an unheated corridor should be included in the HLP calculation and recorded as the length of sheltered wall in the flat/maisonette section of the software. Internal or External Measurements The floor area and heat loss perimeter can be measured internally or externally. Please ensure that a combination of internal and external measurements is not taken during the survey, as only one type can be accounted for in RdSAP. Where external measurements are taken the RdSAP software will subtract the wall thickness from the calculated floor area, and the internal floor area is displayed on the EPC. The wall thickness RdSAP uses is that measured on site and recorded in the software. As a result, the final floor area shown on the EPC may differ from the figure originally calculated. External measurements are often the simplest way of measuring a building, given that there is no furniture to measure round or internal walls to get in the way. A simple building with suitable access can require as few as two measurements. It is not always appropriate to take external measurements Bad weather Restricted access Flat above ground floor Internal measurements should always be used when assessing flats; they are also more suitable if using a laser measure. If measuring internally, remember to include the thickness of internal partitions. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 55

56 1.7 PROPERTY SIZE Room Height The room height should always be measured internally from floor to ceiling If ceiling heights vary then average the height based on the area. Please see the below example To calculate area weighted ceiling height use the following calculation: (Area x ceiling height) + (Area x ceiling height) Total floor area Area Weighted Ceiling Height Example floor areas: Kitchen 22.3m 2 Main living area 44.5m 2 KITCHEN 2.31M MAIN LIVING AREA 2.87M (2.31 x 22.3) + (2.87 x 44.5) Total floor area = =2.68m Property Dimensions Examples Example 1: Detached 2 storey property, with integral garage 8.4M 3.27M UNHEATED INTEGRAL GARAGE 4.9M Ground floor area = (8.4 x 7.43) (3.27 x 4.9) = = 46.39m 2 Ground floor heat loss perimeter = (8.4 x 2) + (7.43 x 2) = 31.66m 1st floor area = 8.4 x 7.43 = 62.41m 2 1st floor heat loss perimeter = (8.4 x 2) + (7.43 x 2) = 31.66m 7.43M If the upper floor has a greater area than the lower floor the software assumes the extra floor area is exposed. In this example 16.02m 2 will be assigned by the software as exposed, this accounts for the heat loss through the floor to the garage. HEAT LOSS PERIMETER 56

57 Example 2: Flat with unheated corridor UNHEATED CORRIDOR 7.93M ASSESSED FLAT 1.74M Floor area = 7.93 x 8.28 = 65.66m 2 Unheated Corridor length = =9.67m Total heat loss perimeter = = 17.6m 1.7 PROPERTY SIZE 8.28M NEIGHBOURING FLAT Example 3: Mid terrace 2 storey house with single storey extension MAIN HOUSE 4.5M 7.42M Main house ground floor area = 4.5 x 7.42 = 33.39m 2 Main house ground floor heat loss perimeter = ( ) = 5.88m Extension 1 floor area = 3.9 x 3.12 = 12.17m 2 Extension 1 heat loss perimeter = (3.9 x 2) = 10.92m Main house 1st floor area = 4.5 x 7.42 = 33.39m 2 PARTY WALL Main house 1st floor heat loss perimeter = 4.5 x 2 = 9m EXTENSION 1 3.9M 3.12M For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 57

58 1.7 PROPERTY SIZE Habitable Rooms This is a count of the number of rooms classed as Habitable, according to RdSAP. To be habitable a room must have a window and fall into one of the following categories: Lounge/living room/sitting room Dining room Bedroom Study Kitchen diner (must have space for a table and 4 chairs) Non-separated conservatory (if there is an internal quality door between it and the dwelling) Measuring Bay Windows The following rooms are NOT habitable rooms: Bathroom Kitchen En-suite bathroom Hallway Stairs Utility room Store room Garage Rooms must be separate to count as individual habitable rooms (a permanently removed door between a dining room and kitchen is classed as one habitable room). For open plan properties, all rooms thermally connected to the main living area count as one room. Bay windows do not need to be accounted for as an extension; any timber wall construction can be accounted for as an alternative wall, and the additional floor area and heat loss perimeter can be incorporated into the part of the property in which they are located (main house, extension etc). Bay windows are usually squared, trapezoidal/canted or curved. There are a number of ways to calculate the area and heat loss perimeter for bay windows; however Stroma suggests a method which requires only 2 measurements to calculate the area and heat loss perimeter of a bay window. SQUARE Area W x D Extra Perimeter 2 x D CANTED Area Extra Perimeter Wp x D 0.8 x D (Wp = partial width) VERY SHALLOW Depth is up to 10% of Width Area Extra Perimeter 0.7 x W x D 0.25 x D 58

59 SHALLOW Depth is up to 20% of Width 1.7 PROPERTY SIZE Area Extra Perimeter 0.7 x W x D 0.5 x D DEEP Depth is up to 30% of Width Area Extra Perimeter 0.7 x W x D 0.75 x D VERY DEEP/ SEMI-CIRCULAR Depth is up to 50% of Width Area Extra Perimeter 0.8 x W x D D Segmented bays (green) and circular bays (red) have the same area/perimeter within 3%. To calculate the total perimeter, measure the whole length of wall (including bay) and add the extra perimeter to the length, see example below. 2.3M Floor area = (5.6 x 6.5) + (Bay window area) 0.95M = (2.3 x 0.95) = = 38.59m 2 6.5M PARTY WALL Heat loss perimeter = (5.6 x 2) + (Extra bay window perimeter) = (0.8 x 0.95) = = 11.96m 5.6M For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 59

60 1.8 SPACE HEATING Space Heating This chapter will cover the following: Identifying Primary and Secondary Heating Identifying Heating Systems (boilers, room heaters etc) Using the SEDBUK database and alternative method Space Heating Controls Different Fuel Types Identifying the System RdSAP allows for three different heating systems to be included in the survey, the main heating system, Additional heating (sometimes referred to as 2nd main heating), and the secondary heating system. Main System The main heating system is defined as: The system which heats the largest proportion of the dwelling A system which is not usually based on individual room heaters (although it can be) Usually the provider of water heating as well as space heating. The main heating system will normally be a boiler which can be identified using the PCDF (Product Characteristics Database File) or alternative method. If there is a central heating system that provides both space and water heating, and it is capable of heating at least 30% of the dwelling, select that system as the main heating system If there is no system that provides both space and water heating, then select the system that has the capability of heating the greatest part of the dwelling. For this purpose, only habitable rooms should be considered If there are still doubts, select the system that supplies useful heat to the dwelling at the lowest cost If the costs are the same, select the system that heats the living room Please note that whilst electric storage heaters may not appear to heat most of the rooms, they heat the property using drift heat. Because the heat drifts through the property, they are not required in each room. If there is doubt regarding the main heating system in a property, use the following identification process: 60

61 1.8 SPACE HEATING 2 nd Main System The facility for an additional main system allows two main heating systems to be included in an EPC. This means a variety of heating systems can be specified in RdSAP. For example, 2 separate boilers used to heat different parts of a dwelling, or a property with a central heating system and storage heaters. Identify the additional main system using PCDF or the alternative method. When there are two main heating systems the proportion of the property heated by each heating system should be calculated. This should be based on floor area and entered into the software as a percentage to the nearest 10%. In the example the property has a boiler supplying a number of radiators, plus the hot water; there are also two storage heaters in two of the bedrooms. The main heating system is the boiler as it is heating the majority of the property, and is also providing the hot water The total floor area is 87.5 sq.m The area heated by the storage heaters is 21 sq.m The calculate the percentage of floor area heated use the following calculation Floor area heated by additional heating system Total floor area The additional main system in the example heats 24% of the property 2 nd Main Heating Supplying Hot Water x 100 The facility for a additional main heating system also allows for when a property has a boiler providing the main heating and another heating device dedicated to providing hot water, such as a range cooker. Enter the water heating device as the additional main heating system and specify the floor area heated as a percentage, then select the additional main heating as the water heating source. If no proportion of the space heating is supplied by this method, enter the water heating using the water heating section. The storage heaters are the additional main system as they heat a smaller proportion of the property As there are two types of main heating system the percentage of the property heated by each system should be calculated. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 61

62 1.8 SPACE HEATING Secondary System The secondary system must be based on fixed room heaters in habitable rooms (heaters found in non-habitable rooms are not usually included in the survey). It is not possible to select a central heating system as secondary heating. If a secondary heating system is present it should be included in the assessment, regardless of whether the central heating heats all the rooms. If there is more than one possible secondary system in a property, use the following process to identify the system which should be selected: That which heats the greatest number of rooms should be specified as a secondary system If this doesn t resolve the choice, select the system which is cheapest to run Portable heaters are generally discounted from the survey because they are likely to be removed from the property when the current occupier leaves. However, there are a few circumstances in which portable heaters are included in the survey: When the main heating is an electric storage system, some form of secondary heating must be identified. If there is no secondary heating in the property then portable electric heaters should be included If the main heating system is not sufficient to heat all the habitable rooms in a dwelling, and there is no secondary heating specified. The software will determine whether it is appropriate to include portable heaters. If there is no heating system present, the software will default the main heating to portable electric heaters Portable heating is defined as: Completely free standing and self supporting not designed to be wall mounted or specifically designed to fit in a fireplace Must contain a built-in fuel store (if gas or oil heater), electric heaters must have a lead and plug Be easily moved from one room to another Focal point electric fires located in a fireplace can be included in the assessment and recorded as electric panel heater, not portable electric heating 62

63 Broken and Missing Heating Systems RdSAP assumes that the installed heating systems are operational and takes no account of whether or not they are working. Similarly if a boiler is present and the gas supply is disconnected, the boiler should still be accounted for in the heating for the property. No Heating System - If the main heating unit is missing then it cannot be included in the survey and any other heating system present in the property may be considered as the main heating (e.g. gas fire). If there is no system present, select no heating in the main heating section of the software. The software will then record portable electric heaters as the main system. Main Heating Systems There are a number of different types of main heating broken down into the following groups: Central heating systems with radiators or underfloor heating Electric storage systems Electric underfloor heating Warm air systems Community Heating schemes Radiators A radiator is the most common form of heat emitter used in central heating systems. The hot water from the main unit (typically a boiler) passes through the radiator, which then emits the heat. A radiator will have a flow pipe, bringing the hot water into the radiator from the boiler and a return pipe, which takes the used, cooler water back to the boiler to be reheated. Underfloor Heating There are 2 types of underfloor heating; those used in central heating (wet) systems, and those in electric underfloor heating. This section will concentrate on the wet system. Underfloor heating is a length of small bore pipes laid under the floor carrying water heated by the main system (usually a boiler). They are laid in a circuit to cover most of the ground floor; there are often a number of loops which can be individually controlled with separate room thermostats. Although not always immediately obvious, there are some simple ways to identify underfloor heating: Lack of radiators Underfloor heating manifold near boiler (as shown in the image) 1.8 SPACE HEATING Room heaters Central Heating A central heating system is usually capable of heating the whole house. It will consist of a main unit, emitters and, in some cases, a hot water cylinder which is fed off the same system. Central heating is sometimes described as a wet system as it involves the flow of water around the system. Essential components of a central heating system are: Main unit (i.e. gas boiler) Heat emitter Radiator Underfloor heating If one heating system feeds both underfloor and radiators, enter radiators. This is because radiators require a higher flow temperature, making radiators the worst case scenario. Main Unit The main unit of a central heating system is likely to be a boiler, either gas, oil, solid fuel or electric. A warm air unit, range cooker or heat pump can also be the main unit. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 63

64 1.8 SPACE HEATING Boiler Identification Gas (including LPG) Boilers Combination Boiler Regular Boiler This is the traditional type of boiler used in central heating systems in the UK. The boiler heats the water that flows around the heating and hot water systems The water used for heating is fed from a header or feed tank usually found in the loft As the water flows around the heating system, it expands. An expansion pipe is fitted to the heating system to discharge any build up in pressure in the system, to the header tank More modern sealed systems do not require the feed/expansion tank as they have expansion vessels instead A combi boiler provides heating in the same way as a regular boiler; in addition it heats hot water as it s required, rather than heating a store of water. Key Ways to Identify a Combi Boiler: A combi boiler has more pipes attached than a regular boiler, usually 5, 6 or 7 No hot water cylinder (although this may be present in some system) Boiler fires up when hot water tap is turned on More controls on the front of boiler, often a programmer and pressure gauge Key Ways to Identify a Regular Boiler: Usually only 3 pipes (gas supply, flow and return) Hot water tank usually present Simple boiler design few controls on boiler If a regular boiler is present, the water heating should be provided by the main system, even if the tank has an immersion heater. This is assumed to heat the water in summer and should not be selected. For further details please refer to the Water Heating section. 64

65 Condensing Boiler A highly efficient boiler type which uses an extra heat exchanger to recover heat from the flue gases before they are emitted. This means the exhaust gases from the flue are at a much lower temperature than a non-condensing boiler. Both regular and combi boilers can be condensing, usually with an efficiency of at least 83% (for Natural Gas). 1.8 SPACE HEATING Key Ways to Identify a Condensing Boiler: The plastic condensate pipe coming from the boiler to an external drain Fan assisted flue, often plastic On a cold day you can see a plume of water vapour coming from the flue CONDENSATE PIPE Electric Fan Heat Exchanger Hot water to radiators Cool water from radiators For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 65

66 1.8 SPACE HEATING Back Boiler The pre-cursor to the modern boiler Pre 1998 gas back boiler to radiators 1998 or later gas back boiler to radiators CPSU Combined Primary Storage Unit Mains gas or LPG CPSU non condensing Mains gas or LPG CPSU condensing Traditionally the open fire would have a boiler fitted behind it to heat water, however this proved largely inefficient. As gas fires became more common, gas back boilers were installed in place of solid fuel back boilers. These appliances are usually sealed to the chimney and have an open flue. This appliance incorporates the provision of space heating and hot water. The hot water store should be at least 70L and integral to the appliance. Pre 1998 gas fire with back boiler to radiators Typical controls for a gas fire with back boiler Key Ways to Identify a Back Boiler: Water pipes coming from the appliance Plate at bottom of gas fire can be removed to reveal boiler controls Presence of radiators and or hot water tank, but no obvious boiler present Gas fired back boilers can be found on the PCDF database. For more details on solid fuel back boilers see later in the chapter Key Ways to Identify a CPSU: The appliance is larger than a conventional boiler and floor mounted There will be no separate hot water tank If a CPSU is selected in the software it is not necessary to include the cylinder details, as this information is assumed by RdSAP. In the water heating section of the software select from main system and no cylinder. 66

67 PCDF Database The PCDF is the Product Characteristic Data File it contains databases for four different types of heating system: - Gas and oil boilers - MicroCHP - Heat pumps - Solid fuel boilers The PCDF stores specific details about a large number of these heating systems including their efficiency, which is used by RdSAP. The PCDF is incorporated into the Stroma software in the heating section. A device can be identified by make and model information, therefore it is vital that the appropriate data is gathered on site to ensure the device is the correct one. Boiler manufacturers sometimes produce a mains gas and LPG versions of the same boiler, so take care when selecting a boiler using the PCDF database. The boiler details will show whether it is a mains gas or LPG boiler. Selecting a boiler with the wrong fuel type can significantly affect the EPC rating. 1.8 SPACE HEATING When identifying a device, most modern devices will be clearly labelled with the model number, but older boilers may require a little investigation. Look for ID plates such as those pictured. If the device is not in the PCDF database, or there was insufficient information to accurately select the boiler, the alternative method must be used. This is based on the heating descriptions in SAP SAP Tables (Alternative Method) This way of identifying a boiler applies a generic efficiency, based on the type of boiler, and is not specific to make or model. This covers a far wider range of heating systems. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 67

68 1.8 SPACE HEATING Flues The flue type can help in identifying the boiler type and its location. There are a number of flue types which differ between boiler type and age. Open Flue This is usually found in properties with older, floor mounted boilers. The combustion gases are taken from the room the boiler is located in, the hot gases rise up the flue, drawn up by wind passing over the top of the flue opening. If an appliance has an open flue, the room must be ventilated (usually with an air brick). Exhaust gases go up flue or chimney Air supply from room Balanced Flue This flue type uses air from outside the dwelling for combustion, and relies on natural air movement to draw hot air back outside. The flue length must be short, with no bends for the natural air movement to work. This means that the boiler must be located on an external wall close to the flue terminal. A balanced flue is classed as room sealed because all combustion air is drawn from outside. Flue terminals are usually large, square and steel and, if located low down, the flue should be covered with a grill for protection against the high temperature of the emitted combustion gases. This type of flue was commonly fitted for pre 1998 gas boilers. In order for the flue to work effectively, there must be enough natural air movement to allow the cold air to be drawn into the boiler (see diagram). 68

69 Balanced Flue Diagram 1.8 SPACE HEATING Warmed air circulates around the room Cavity Wall Flue gases come out through central pipe wire guard for flue terminal Outer Casing Combustion air pulled in through outer pipe Cool Air For more information contact Stroma Certification at ext. 614 alternatively 69

70 1.8 SPACE HEATING Fan Assisted Flue This is a type of room sealed flue which uses a fan to move the air through the flue pipes. The flue does not have to rely on natural air movement so the flue pipes can be longer with bends in them if necessary. This means that it is not necessary for the boiler to be located on the external wall. Fanned flue appliances tend to be more efficient than those with a balanced flue because more heat can be taken from the combustion gases before they leave the boiler. External air sucked into combustion chamber Hot exhaust gases Electric Fan Heat Exchanger Hot water to radiators Cool water from radiators 70

71 Flue Gas Heat Recovery Systems (FGHRS) Flue Gas Heat Recovery systems are designed to recover heat in the flue gases discharged from a condensing boiler if it is fired by natural gas, LPG, or oil. 1.8 SPACE HEATING The system recovers the heat from the flue gases which is then used to pre-heat the cold water before it enters the boiler. This reduces the amount of fuel that is burned heating the water. These systems can be one of two types: Passive - this is a system that is integral to the boiler Seperate - these systems are retrofitted to existing boilers You can only enter a Flue Gas Heat Recovery System if it is present within the PCDF. If you cannot find it within the PCDF, it has to be disregarded but recorded in your site notes. FGHRS can be fitted to a seperate hot water store. If this is the case it may be powered by Solar Photovoltaics. Make sure you check for a Solar PV array on the property specifically designed for the FGHRS. A flue gas heat recovery system will normally be found just above the boiler unit. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 71

72 1.8 SPACE HEATING Other Heating Systems These heating systems are not listed in the PCDF database, meaning the alternative method must be used to identify them in the software. Electric Boilers Electric direct acting boiler This boiler type is increasing in popularity, particularly in modern flat developments. The unit is a narrow device, about 1 metre long. It can provide wet central heating and hot water if connected to a hot water tank. The units are usually found attached to the wall in a cupboard with the hot water tank. They can be fitted in properties with peak or dual rate tariffs but they are not considered to be storage systems as they do not fully utilise the off peak rate. Common examples of an electric direct acting boiler is the Heatrae Sadia Amptec and Trianco Aztec Classic. Electric CPSU in Heated Space Like the gas CPSU, this device combines the space and water heating in one unit. A large water store is heated using off peak electricity and the stored water is then piped to radiators. A heat exchanger provides hot water at mains pressure. The minimum capacity of an electric CPSU is 270L. This makes the unit quite big, usually around 1.8m tall. Please note if an electric CPSU is entered, it is not possible to include any secondary heating. In addition, if a CPSU is selected in the software it is not necessary to include the cylinder details; this information is assumed by RdSAP. In the water heating section of the software select from main system and no cylinder. Photo courtesy of Gledhill Electric Dry Core Storage Boiler This works in a similar way to an electric storage heater, using off peak electricity to heat bricks inside the boiler. Heat from the bricks is blown onto an air-to-water heat exchanger to provide space and water heating. Photo courtesy of Hyndburn Engineering Services Ltd

73 Electric Water Storage Boiler This device makes use of off peak electricity. It has a water store which is heated overnight to supply the property with heating and hot water. 1.8 SPACE HEATING The water tank in an electric water storage boiler will usually be less than 270L. If the tank capacity is any greater, the device is likely to be an electric CPSU. Solid Fuel Boilers Range Cooker Boiler To be included in RdSAP the range cooker must incorporate a boiler capable of providing space heating. Range cookers can be fuelled by gas, oil or solid fuel. There is only one option for solid fuel range cookers: Range cooker boiler (integral oven and boilers). Gas and oil ranges can be identified as a single or twin burner. A twin burner has two burners; one for the cooker and one for the heating. A single burner range has one burner for both heating and cooking. Range cooker boiler (mains gas and LPG) single burner with permanent pilot light Range cooker boiler (mains gas and LPG) single burner with automatic ignition Range cooker boiler (mains gas and LPG) twin burner with automatic ignition Range cooker boiler (oil) single burner Range cooker boiler (oil) twin burner Some range cookers may only provide hot water for a dwelling, please see the water heating chapter for more details on this. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 73

74 1.8 SPACE HEATING Back Boiler A number of gas back boilers are listed on the PCDF database. Therefore, where possible please use the PCDF database to enter the boiler. Those not listed on PCDF should be entered using the alternative method. All other types of back boiler fit into the following categories: Open fire with back boiler. Although they are not always easy to identify, the presence of a central heating system but no obvious boiler may indicate the installation of a Back boiler A closed room heater with back boiler. These can be gas or solid fuel and are usually identifiable by flow and return pipe work coming from the appliance Closed room heater with back boiler A pellet fired stove with back boiler. This type of back boiler is specifically fuelled by wood pellets All Back boilers can be considered as main or secondary heating. Please note that when entering the main heating system with Back boiler, the room heater should also be considered as secondary heating. Solid Fuel Boiler Manual or Auto (gravity) Feed Manual feed independent boiler in heated space Manual feed independent boiler in unheated space Auto (gravity) feed independent boiler in heated space Auto (gravity) feed independent boiler in unheated space Wood chip/pellet independent boiler Solid fuel boilers can be fuelled by traditional solid fuels, e.g. anthracite, or they can run on biofuels such as wood pellets. These boilers possess a hopper, integral to the boiler, which is used to automatically feed fuel. Alternatively, fuel can be manually fed. Gravity fed boiler fuelled by anthracite Solid fuel boilers are usually regular boilers capable of providing the heating and hot water for a property. It may not be immediately clear what fuel the boiler runs on; check the property for a fuel store as this should indicate what fuel the boiler uses. 74

75 Electric Storage Systems Storage heaters make use of cheap rate electricity (off peak) by storing heat overnight and releasing it during the day. Because they rely on drift heat, these storage heaters are usually placed in hallways, landings and main living area, rather than in each room. 1.8 SPACE HEATING Old (large volume) Storage Heaters Older storage heaters tend to be large (around 20-25cm deep) and sit directly on the floor due to the weight of bricks inside the heater. They may be dark brown or beige in colour. Modern (slim line) Storage Heaters Modern slimline storage heater Modern storage heaters are narrower (10-15cm deep) and wall mounted, with small feet to support their weight. They often have vents at the top of the heater. Fan Storage Heaters Some more modern storage heaters are fan assisted to help improve the distribution of heat from the device. These types of heater can be identified by additional vents at the bottom of the heater and two separate wires coming from the device. One goes to the off-peak meter for over night charging, and one to the peak rate meter for the fan which is active during the day. Integrated Storage and Direct Acting Heater These heaters are similar in appearance to the fan storage heaters and incorporate an on-peak electric heater to provide on-demand heat. If a property has this type of storage heater it is not necessary to include separate electric panel heaters as secondary heating. Fan assisted storage heater When the main heating is from electric storage heating a secondary system should be specified, please refer to the table for full details. If no secondary heating system is present at the property then portable electric heaters should be included as the secondary heating. Main heating system Secondary heating MUST be specified Old (large volume) storage heaters Modern (slim line) storage heaters Fan storage heaters Integrated storage and direct acting heater Electric underfloor in concrete slab (off-peak only) Electric underfloor integrated (storage and direct acting) Yes Yes Yes No Yes No Storage heaters and a single meter If storage heaters are present as main heating but there is only a single meter then enter the main heating as electric panel heaters and include addendum 6. If the storage heaters are fan-assisted then suppress the recommendation for fan-assisted storage heaters For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 75

76 1.8 SPACE HEATING Electric Underfloor Heating Cables are laid under the floor so they can t usually be seen. Normally it is possible to identify them by the wall mounted controls. Screed Heating cables In Concrete Slab (off-peak) This system uses the floor to store heat, similar to the way storage heaters store heat in bricks. There should be an off-peak tariff available to the property and, as with storage heaters, a secondary heating system should be entered. If there is no secondary heating present, select portable electric heaters. Insulation Damp proof membrane In screed above insulation In Screed Above Insulation (standard tariff) This system has embedded cables under the floor, but they are located closer to the surface to provide immediate heat. The system uses peak rate electricity and is often installed in one room (usually the bathroom or kitchen) which means it is not often classed as primary heating for a property. Integrated (storage & direct acting) This system can be used with on-peak and off-peak tariffs. Some systems have two sets of cables, one placed lower in the floor for storage heating and the other nearer the surface for direct heating. Warm Air Systems Warm air systems can run on gas, oil or electricity. The main unit is normally floor mounted and about metres tall and cm wide. The system blows heated air through ducts or stub-ducts (shorter ducting) around the house, and out through low level vents in the walls. The vents are a useful indicator that a warm air system is installed. Electric warm air systems use off peak electricity to store heat overnight, therefore the property should have a dual electricity meter. All warm air systems can work alongside a hot water circulator to supply hot water to a cylinder. Gas fired warm air with fan assisted flue, ducted, pre 1998 Oil fired warm air ducted output Electric warm air electricaire system Gas fired warm air with balanced or open flue ducted or stub ducted, pre 1998 Gas fired warm air with balanced or open flue ducted or stub ducted with flue heat recovery Gas fired warm air with balanced or open flue condensing 76

77 Electric Ceiling Heaters This form of heating is unusual in domestic properties and was predominantly installed in the 1970s and 80s, though it is still fitted in some modern developments. Electric ceiling heating works in a similar way to underfloor heating, with panels embedded in the ceiling construction and insulation installed above, to reduce heat loss through the ceiling. Warm air vents in the ceiling should be assessed as part of a warm air system. 1.8 SPACE HEATING Joists Insulation Insulation Gypsum Board Heating Element Heat Pumps Heat pumps are becoming more common in the UK, particularly ground source and air source heat pumps. They can be used in conjunction with a wet central heating system or warm air system. All heat pumps work by extracting heat from a low-temperature source and increasing the temperature so it can be used for heating. This results in 100% plus efficiency, as the amount of energy used is less than the heat energy generated. Ground source heat pumps use pipe-work buried underground to extract heat from the soil. This requires a large amount of land, which restricts their installation for many domestic properties. Air source heat pumps look similar to air conditioning units and take heat from external air. They can be mounted on an external wall and require minimal space. Ground to water heat pump Ground to water heat pump with auxiliary heater Water to water heat pump Air to water heat pump Ground to air heat pump Ground to air heat pump with auxiliary heater Water to air heat pump Air to air heat pump For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 77

78 1.8 SPACE HEATING Community Heating Community heating is defined as a system which provides heat for more than one dwelling, usually from an industrial sized boiler system, housed in a specific boiler room. There are three community heating options in RdSAP: Community boilers only Community Heat Pump Community CHP (combined heat and power) and boilers What is CHP? Combined Heat and Power means the system generates electricity on site and the heat, produced as a by-product of the process, is used for the heating. CHP systems are not very common and their presence must be verified prior to inclusion. The building manager should have some information about the system in place. Community heating with CHP has lower costs for heating and hot water due to the way the heat is produced. This can sometimes have a significant effect on the EPC. If it isn t possible to ascertain the fuel type for a community heating system then select Mains Gas. It is important to select the correct option. As it is not always possible to access the boiler room, it may be necessary to contact the building manager. In most cases, community heating systems will have some form of hot water store and a cylinder should be included in the hot water section. Please refer to the Water Heating chapter for further details. In cases where a few flats are heated by the same domestic boiler, if possible enter the actual boiler details using the PCDF or the alternative method. Only when there is no access to the boiler should community heating be selected. Micro CHP Micro CHP are smaller scale than standard CHP, and are mainly for single dwelling use. These units are gas fired engines delivering modest heat outputs (typically below 8kW) and 1-2 kw of electricity generation. Micro CHP are heat led which means they only generate electricity when the heating is on. Any excess electricity that is not used is sent directly back to the grid. Micro CHP does not have a SAP table method and can only be entered using the PCDF, if it not present on the datafile it should be entered via the SAP tables as a gas condensing boiler. 78

79 Room Heaters Room heaters can be included in the survey as main heating or secondary heating, dependent upon other systems fitted in the property. They are split into four categories based on the fuel they use. 1.8 SPACE HEATING Gas room heaters Oil room heaters Electric room heaters Solid fuel room heaters Gas Room Heaters Gas Fire, Open Flue Pre 1980 (open fronted) (with back boiler) The open flue indicates the combustion gases come from the room. Ceramic blocks radiate the heat when lit. Can be with or without a back boiler. Efficiency: 50% Gas Fire, Open Flue Pre1980 or Later Sitting Proud of and Sealed to Fireplace Opening. (with back boiler) This appliance can be found with or without a Back boiler. Efficiency: 63% Both of these appliances sit proud of the fireplace, and are open fronted. Open fronted means the combustion gases are not sealed from the room. For a room heater to be closed fronted it must be sealed from the room, usually with a glass panel. Gaps around the glass mean it is not sealed and should be entered as open fronted. Flush fitting live fuel effect gas fire (open fronted) sealed to fireplace opening (with back boiler) This appliance sits where the fireplace would be. The appliance should be a single unit which fits into the fireplace and controls the air flow up the chimney, (see picture). Efficiency 40% For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 79

80 1.8 SPACE HEATING Decorative Fuel Effect Gas Fire, Open to Chimney Similar to the flush fitting gas fire, this type of fire sits where the fireplace would be. This appliance sits below an open chimney. With no way of restricting the airflow, the efficiency of the appliance is very poor. Efficiency: 20% Gas Fire, Closed Fronted, Fan Assisted This appliance must have a glass panel sealing it from the room. An integral fan blows the heat from the fire into the room. The appliance must have a balanced flue. Efficiency: 72% Gas Fire or Wall Heater, Balanced Flue The appliance must have a balanced flue which is located on the outside wall, in line with the gas heater. This type of appliance must be located on an external wall. Efficiency: 58% Flueless Gas Fire This type of gas fire is considered highly efficient as there is no heat loss up the flue. In addition, these types of fires can be freestanding. Efficiency: 90% Condensing Gas Fire This type of gas fire is very rare, it should have a condensate pipe and fanned flue. One of the main manufacturers of condensing gas fires is Mantis. Efficiency: 85% 80

81 Oil Room Heaters Room Heater, pre 2000 (with or without back boiler) Efficiency: 55% (65%) 1.8 SPACE HEATING Room Heater, 2000 or later (with or without back boiler) Efficiency: 60% (70%) Oil room heaters are likely to be found in rural areas without mains gas, where the main heating is fuelled by oil. Therefore an oil supply is available for the room heater. Please note: oil filled heaters are not classed as oil room heaters. These types of heater should be entered as water or oil filled radiators in place of portable electric heaters image courtesy of ACR Heat Products Ltd. Bioethanol heater secondary heating only Efficiency: 94% A flueless heater usually installed for more decorative purposes than as a heat source. The bioethanol fuel used by these appliances is very expensive, making it a costly form of secondary heating. Solid Fuel Room Heaters Stove (Pellet fired) - efficiency: 63% Stove (pellet fired) with back boiler - efficiency: 63% These room heaters are fuelled specifically by wood pellets Open Fire in Grate (with or without Back boiler) Efficiency: 32% (with back boiler: 50%) An open fireplace is to be considered in the heating assessment if capable of supporting an open fire, even if no fuel is present. Open fireplaces in bedrooms are disregarded when identifying heating systems and heated habitable room count, but are counted in the number of open chimneys if appropriate. Closed Room Heater (with or without Back boiler) Efficiency: 60% (with back boiler: 65%) Solid fuel room heaters are the traditional way to heat a property, but are highly inefficient as most of the heat goes up the chimney. If the solid fuel room heater is regularly used, there may be a companion set close by, plus fire guard and the fuel used. If it is not clear what the fuel type is then: Smoke control area - Open fire - smokeless fuel; closed room heater anthracite Not smoke control area - Open fire dual fuel; closed room heater wood logs if capable, otherwise anthracite For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 81

82 1.8 SPACE HEATING Electric Room Heaters (Direct Acting) Panel, Convector or Radiant Heaters This category can include wall mounted panel, fan and radiant heaters, plus electric fires. Modern electric fires can be deceptive in their appearance, some look like gas fires unless inspected more closely. All of these appliances must be fixed, or located in a fireplace; otherwise they are classed as portable electric heaters. Water or oil filled radiators Efficiency: 100% Fixed electric heaters, often with the appearance of a normal radiator, but they are not on a centralised system. They will also have electrical wiring where you would expect to see water pipes. Portable Electric Heaters Generally portable heaters should be ignored as it is assumed that the occupants will take the heaters with them when they move. These heaters should only be included when an electric storage heating is the main heating system and no other form of secondary heating is present in the property. If there is no heating system present in the property, RdSAP assumes electric portable heaters as the main heating system in the property. 82

83 Room Heaters with Back Boilers The below examples all relate to gas room heaters, but the same applies to solid fuel and oil room heaters. This table demonstrates what to select as primary or secondary heating. 1.8 SPACE HEATING Example Primary Heating Secondary Heating Water Heating A room heater has a back boiler providing hot water to a central heating system This should be entered as the primary heating system. The room heater also provides direct heat to the room; therefore it should also be entered as secondary heating Primary selection: Central heating systems with radiators or underfloor heating Secondary selection: Gas boilers (including LPG) pre-1998, with balanced or open flue Select product: Back boiler to radiators Secondary selection: Gas (including LPG) room heaters Select product: Gas fire, open flue, 1980 or later (open fronted) sitting proud of and sealed to fireplace opening with back boiler unit Heating type: From main heating system Enter cylinder details as appropriate A room heater has a back boiler providing hot water to a cylinder only There is no other form of heating in the property; therefore the room heater should be entered as the primary heating system Primary selection: Room heaters Secondary selection: Gas (including LPG) room heaters Select product: Gas fire, open flue, pre 1980 (open fronted) with back boiler unit No secondary heating present Heating type: From main heating system Enter cylinder details as appropriate A room heater has a back boiler providing hot water to a cylinder only, and the property is heated by another system (such as storage heaters or a warm air system) The room heater should be entered as secondary heating and the water heating as from secondary system Primary selection: Warm air systems Secondary selection: Gas fired warm air with balanced or open flue Select product: Ducted or stub-ducted, on-off control, pre 1998 Secondary selection: Gas (including LPG) room heaters Select product: Gas fire, open flue, 1980 or later (open fronted) sitting proud of and sealed to fireplace opening with back boiler unit Heating type: From secondary heater Enter cylinder details as appropriate A room heater has a back boiler providing hot water to a cylinder only; there is also a modern regular boiler in the property providing heating and hot water The room heater should be entered as secondary heating, but the water heating is from main system because the back boiler is considered an additional method of water heating Primary selection: Central heating systems with radiators or underfloor heating Secondary selection: Gas boilers (including LPG) 1998 or later Select product: Regular non-condensing with automatic ignition Secondary selection: Gas (including LPG) room heaters Select product: Gas fire, open flue, 1980 or later (open fronted) sitting proud of and sealed to fireplace opening with back boiler unit Heating type: From main heating system Enter cylinder details as appropriate For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 83

84 1.8 SPACE HEATING Fuel Mains Gas LPG Mains gas is piped to individual properties and is one of the cheapest and cleanest fuels widely available in the UK. Many rural towns, villages and more remote areas are not on the mains gas network and must use alternative fuels. One of the questions in the survey is whether mains gas is available. If a property s heating is not fuelled by mains gas but it is available to the property, the software will calculate whether a fuel switch is appropriate. Mains gas is assumed to be available to a property if there is a gas meter at the property and/or a mains gas appliance is fitted at the property. In the case where the gas supply to a property has been disconnected, e.g. a repossessed property, where the gas meter has been removed or the supply capped off, mains gas should still be entered as available. If mains gas is available to the local area, but has not been piped to the surveyed property, the mains gas should not be selected as available. The cost of the work to pipe the gas to a property is usually very high and would make a fuel switch and installation of a gas condensing boiler too expensive. Liquid Petroleum Gas is common in areas off the mains gas supply. The LPG is usually stored outside in a large metal tank (when purchased in bulk) or smaller cylinders. The tank is often located in the garden and can sometimes be buried, meaning only a large manhole cover can be seen. LPG is a manufactured fuel, meaning it has higher costs and carbon emissions than other fuels. As a result, properties with LPG often receive a poor EPC rating; it may be worth advising the home owner of this fact during a survey on a property with LPG. LPG is subject to special condition 18; Applies only if documentary evidence confirms that the property receives LPG at mains gas prices. Boiler manufacturers sometimes produce a mains gas and LPG version of the same boiler. Take care when selecting a boiler using the PCDF database - the boiler details will show whether it is a mains gas or LPG boiler. Selecting a boiler with the wrong fuel type can significantly affect the SAP rating Oil Heating oil is also common in areas off the mains gas supply. It can be bought in bulk and stored in a tank. Oil tanks can be made of metal or moulded plastic and are usually larger than LPG tanks. Additional fuel types Bioethanol and LNG Bioethanol This fuel type should only be used when a bioethanol room heater has been specified as the secondary heating. This fuel is very expensive in comparison with all other fuels in RdSAP LNG Liquid Natural Gas is used as an alternative to LPG, oil or mains gas. It is equivalent in price to mains gas. If a property has LNG there should be a storage vessel in the grounds of the property. B30K A new fuel blend which is 30% mic of biofuel, coupled with 70% kerosene. This new bioliquid is designed to work in existing oil heating appliances. This can only be entered with documentary evidence. Oil boilers are usually quite distinctive, often floor mounted and larger than gas boilers. 84

85 Solid Fuel: Coal, Anthracite, Smokeless Fuel, Wood 1.8 SPACE HEATING Coal can be burnt in open and closed room heaters, but cannot be used in smoke control areas. Anthracite is a naturally smokeless type of coal which is usually supplied as grains or nuts, and can be used in central heating boilers. Smokeless Fuel is used as a replacement for coal in smoke control areas; it can be used in open and closed room heaters, but is more expensive than coal. As it is a manufactured fuel, the coals are usually uniform in shape. Wood is also referred to as biomass, and although it releases carbon when burnt, it does not exceed the amount of carbon absorbed by the tree whilst it was growing. Therefore, it is considered carbon neutral. Wood is available as logs, pellets and chips. Pellets and chips can be used in biomass boilers and tend to be bought in bulk, so there should be a pellet/chip store at the property. Wood logs are generally used in open and closed room heaters. A dual fuel appliance can burn mineral (coal, anthracite etc.) and biomass (wood) fuels and most solid fuel open and closed room heaters are capable of burning both types. If it is not clear what fuel is burnt in a solid fuel room heater, dual fuel is the most appropriate option. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 85

86 1.8 SPACE HEATING Electricity There are 3 options for electricity meters in RdSAP (There are 4 options in Scotland) Single This is the standard tariff for domestic properties and means the electricity is charged at a standard rate Dual This means a property has an additional tariff, known as off-peak / Economy 7 in England, Wales and Northern Ireland, or Economy White Meter in Scotland. This tariff is charged at a lower rate than standard tariff electricity. The off-peak period is usually a 7 hour period overnight, and electric storage systems have been developed to take advantage of this. If a property has a dual tariff there must be a facility to display a meter reading for each tariff. Originally properties with dual electricity would be fitted with two separate meters, whereas more recently the meters have been combined to show two reading within the same meter. Modern digital meters have a button to switch between two different readings. Dual tariff meters often have Economy 7 written somewhere on the meter. (Economy 10 is available in some areas: it has 3 separate off peak periods, typically 5 hours during the night, 3 hours in the afternoon and 2 hours in the evening, but it only applies the cheaper rate to space and water heating). Unknown This option should be selected if it is not possible to access the electricity meter. The software will assume the property has a single rate meter. 24 Hour Tariff Available in Scotland and some parts of Northumberland. This tariff is for use with storage systems, the main heating, secondary heating and water heating for the property are all charged at the 24 hour rate. The storage heaters can be recharged at any time, but this is determined by the electricity company. The 24 hour rate only applies to the heating; any appliances, lighting etc. use the standard tariff. Please Note: Single Phase is often printed on digital meters; this does not relate to the tariff, most dwellings will have a single phase supply. 86

87 Controls Control options differ between different types of heating system. There are 8 heating groups in total and control options in each of these groups differ based on the system in place. 1.8 SPACE HEATING Group 0: No Heating System Present Analogue Programmers Group 1: Boiler Systems with Radiators or Underfloor Heating Group 2: Heat Pumps with Radiators or Underfloor Heating Group 3: Community Heating Schemes Group 4: Electric Storage Systems Digital Programmers Group 5: Warm Air Systems (Including Heat Pumps With Warm Air Distribution) Group 6: Room Heater Systems Group 7: Other Systems Groups 1, 2, 5, 6 & 7 all include some or all of the following controls. Programmer Used to determine the times when the heating is switched on or off. The programmer is usually located near the boiler or hot water tank or may be integral to the boiler. Room Thermostat A room thermostat measures the air temperature and signals to the boiler to switch off when a temperature, set by the user, is reached. Standard dial Combined room and programmer Room stats are usually wall mounted and can often be found in the hall or living room. The thermostat on a boiler should not be accounted for as a room thermostat; it controls the temperature of the water leaving the boiler, but cannot switch the boiler off when a set room temperature is reached. Wireless room thermostats are available so the device might not be fixed to a wall, but the digital transmitter will be located near the boiler, indicating that there may be one present. Ask the owner if you are unable to locate the room thermostat. Combined room thermostats and programmers are increasingly common, usually identified by time and temperature displayed on the same device. Old room thermostat temperature in fahrenheit Frost stat Please Note: the presence of a Frost stat should not be accounted for as a room thermostat. A Frost stat is usually fitted when a boiler is located outside the heated part of a dwelling, typically in a garage or outhouse. They differ from room thermostats because either there are no numbers marked, or the numbers indicate low temperatures up to about 10 degrees. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 87

88 1.8 SPACE HEATING TRVs Thermostatic radiator valves control the temperature of individual radiators by adjusting the hot water flow rate through a radiator, thereby altering the heat output from the radiator. TRVs have marks on them to indicate the amount of heat emitted from the radiator. Radiator cut off valves do not allow control of the heat emitted by the radiator, they simply allow the user to turn a radiator on or off. Please Note: TRVs must be fitted to at least 50% of all radiators to be included in the survey. Bypass Not a physical control, the bypass indicates the presence of a radiator or loop of pipe work with no TRV. It means that hot water can continue to circulate even if all the radiators with TRVs have reached the correct temperature. This control is only relevant when there is no room thermostat in a property. Zone Control a property can be split into 2 or more zones which have independent control for both time and temperature. The programmer will be specifically designed for zone control; the display should indicate the separate zones, each zone should also have its own room thermostat. Boiler Energy Manager This device is used alongside a programmer and TRVs. It monitors the water temperature in the system and adjusts the boiler temperature accordingly. It can incorporate any of the following features: Weather/load Compensation Adjusts boiler temperature according to internal or external temperature Night Setback Maintains a low temperature overnight, reducing the warm up time of the dwelling There are a few BEMs on the market such as the Danfoss BEM

89 Control Options for Central Heating Systems No time or thermostatic control of room temperature This should be selected if no controls are present at the property. Please note if a property has TRVs but no other controls no time or thermostatic control of room temperature should be selected and include the addendum SPACE HEATING Programmer, no room thermostat Room thermostat only Programmer and room thermostat The space and water heating can be set to turn on and off by the programmer but there is no control of the dwelling temperature There is only temperature control of the heating system; the boiler will only turn off when the set temperature is reached, or if it is switched off manually A programmer and room thermostat are both present Programmer and at least two room thermostats Where two room thermostats are present but the programmer cannot control separate zones. This means different temperatures can be set by the two thermostats but the system will be turned on and off at the same time. This should not be entered as Time and temperature zone control Programmer, room thermostat and TRVs Programmer, TRVs and bypass The heating is controlled by a programmer and room thermostat, plus at least 50% of the radiators have TRVs fitted. If less than 50% of the radiators have a TRV fitted the TRVs cannot be accounted for in the survey and the controls should be entered as Programmer and room thermostat Programmer and TRVs present at the property, but no room thermostat. The bypass is usually a radiator with no TRV, but if a property has only a programmer and TRVs on all radiators this control option should be selected Programmer, TRVs and boiler energy manager Controls are a programmer and TRVs on at least 50% of the radiators, plus a boiler energy manager. Time and temperature zone control A system which can independently control the temperature and timing of heating for separate zones within the same property. (TRVs should not be classed as zone control of temperature) TRVs and bypass This option should be selected when there is no programmer or room thermostat present in the property. There must be TRVs on at least half the radiators if this option is chosen. Controls for Warm Air Systems, Electric Underfloor Heating and Electric Ceiling Heating These control options are very similar to central heating options, but without TRVs or boiler energy manager. No thermostatic control of room temperature Programmer, no room thermostat Room thermostat only Programmer and room thermostat Temperature zone control Time and temperature zone control For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 89

90 1.8 SPACE HEATING Controls for Storage Heating systems Manual charge control Most storage heaters have two dials, one to control the overnight charge rate and one to control the output from the heater. These controls tend to have a scale of 1 to 6, though this can vary between different models. Automatic charge control This type of control is a recent development for storage heaters and not particularly common. A thermostat measures the room temperature and the charging of the storage heater is automatically adjusted based on the room temperature. Automatic charge control is not easily identified; occasionally the model name of the heater may provide a clue. The Dimplex XL has manual charge control and the Dimplex XLS has automatic charge control. Automatic charge control is assessed as more efficient in RdSAP. If you are unsure which control the storage heaters have, manual charge control should be selected. Controls for Room Heaters No thermostatic control of room temperature Appliance thermostats Programmer and appliance thermostats Room thermostats only Programmer and room thermostats This should be selected when the appliance only has an on/off switch. These control options refer to controls on individual heaters This control options refer to central controls for all room heaters. A room thermostat and/or programmer similar to those found for a central heating system should be present in the property. Controls for Community heating schemes Electric panel heater with appliance programmer and thermostat on the heater. Community heating controls fall into 2 categories, flat rate charging and unit charging. Flat rate charging means that each dwelling within the community system is charged at the same rate, regardless of individual use, although charges can vary, for example according to dwelling size. Unit charging means each property s energy use is monitored, usually by metering, and charged for their actual energy use. The control options are similar to those for central heating systems. Flat rate charging, no thermostatic control of room temperature Flat rate charging, programmer, no room thermostat Flat rate charging, room thermostat only Flat rate charging, programmer and room thermostat Flat rate charging, programmer and TRVs Charging system linked to use of community heating, unit charging programmer and TRVs Flat rate charging, TRVs Charging system linked to use of community heating, room thermostat only Charging system linked to use of community heating, programmer and room thermostat Charging system linked to use of community heating, TRVs 90

91 Water Heating 1.9 WATER HEATING This chapter will cover: Types of Water Heating Water Heating Components Solar Water Heating RdSAP requires information about the water heating system in a property. Hot water use is based on total floor area of the property only. The number of current occupants and their habits are not accounted for by RdSAP and are not used to calculate hot water use - instead a standard occupancy is assumed based on the size of the property. Water heating is usually provided by the main heating system or electric immersion, although there are a number of possible options. No Hot Water System Present - Electric Immersion Assumed This option should be selected if there is no way of heating water in the property. The software assumes a normal size cylinder with electric immersion. If there is simply no access to the water heating, such as in a community heating system or if the cylinder is boarded into a cupboard, then no access should be selected in the cylinder details (rather than assuming there is no system in place). From Main Heating System Most properties have a central heating system with a regular or combi boiler which provides both heating and hot water. If the boiler is regular there will be a cylinder present in the property. From main heating can be selected when the main heating system is: Any boiler type (regular or combi) Warm air system Heat pump Some community heating schemes From additional main system If the two heating systems have been specified in the survey then either of them can be identified as the source of hot water, providing the device specified is capable of producing it If a property has a device installed specifically to provide domestic hot water, but does not provide any space heating, such as a range cooker, or regular boiler, then it can be included as additional main heating in the heating section of RdSAP.If this is the case then the percentage of the property heated by the additional main heating should be entered as 0, and the water heating can be selected as from additional main heating system. If a cylinder has an immersion heater fitted, and is in a dwelling with any of the above systems, the immersion heater is assumed to be an additional method of providing hot water, usually during summer, and should not be included in the assessment. From Secondary System In some circumstances, it is possible for the secondary heating to supply hot water. The secondary heater must have a back boiler, and there should be a hot water cylinder present at the property. This option should only be selected if the main heating system does not provide any hot water. If two main heating systems have been specified in the heating section then it is possible to use the additional main heating as the source of domestic hot water. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 91

92 1.9 WATER HEATING Typical Hot Water Cylinder in Central Heating System The heat exchanger carries heated water from the boiler - the main way of heating the water in the cylinder. The immersion heater is present, but used as an additional form of heating to the boiler. This is usually used during the summer when the boiler is not required as much for space heating. Immersion heater To taps Heat exchanger/coil Flow from boiler Return to boiler From cold water cistern Flue Gas Heat Recovery System FGHRS recovers heat from the flue gases of a condensing boiler, the heat is then used to heat the hot water supply. A FGHRS can be integral to the boiler, or fitted externally to an existing boiler. If the system is integral then selecting the correct boiler from the boiler database will ensure the FGHRS is included. If the system is fitted to an existing boiler then it must be located in the database in the RdSAP software. It is likely that the system will be fitted to the top of the boiler. Ensure photograph evidence of the device is collected. Where the FGHRS cannot be found in the database then it cannot be included in the survey, but its presence should be recorded in site notes. Waste Water Heat Recovery System This type of system recovers heat from waste warm water from a shower and uses it to pre-heat hot water. It is difficult to retro-fit this type of system, so they are only likely to be found in new builds, or where a bathroom has been renovated. In addition it is unlikely the system will be visible, therefore documentary evidence should be gathered. WWHRS must be included in the database for them to be included in the survey. If the system is not listed it cannot be included in the survey, but its presence should be recorded in site notes. The system only works in conjunction with a mixer shower, where the hot water comes from a boiler, hot water tank or immersion heater. An electric instantaneous shower is not a mixer shower and cannot be included where only this type of shower is present in a property. A mixer shower attached to bath taps is recorded as a mixer shower only if there is a permanent bracket over the bath and there is a shower curtain or screen. In order for RdSAP to determine whether a recommendation for WWHRS should be included, it is necessary to collect the following data in every property surveyed: Number of rooms with bath and/or shower (including rooms with an electric shower) Number of rooms with mixer shower and a bath Number of rooms with a mixer shower and no bath 92

93 Many hot water cylinders have immersion heaters, but this is often an additional way of heating hot water, secondary to a regular boiler. It is unusual for water to be heated by electric immersion if a boiler is present in the property. Properties with water heating only through electric immersion are likely to have electric storage heaters or room heaters (without a back boiler) as the main heating. 1.9 WATER HEATING Cylinder with Single Immersion - The cap of the immersion heater is usually visible on top of the cylinder, and should have an electrical wire going to a hard wired switch nearby. To taps To taps From cold water cistern From cold water cistern Cylinder with dual immersion - Dual immersion heaters are usually installed in properties with a dual electricity tariff. The immersion heaters are often located at the sides of the cylinder. The first, normally found close to the bottom of the cylinder, uses off-peak tariff electricity and heats the whole cylinder of water overnight. The second is typically placed at the top half of the cylinder, and uses peak-rate electricity. Commonly referred to as the Boost, this upper immersion heater is normally used in the evening to provide a small amount of hot water, as the water in the tank will have cooled down during the day. Given that it runs on expensive peak rate electricity, the Boost only heats the water in the top of the tank. Both of the immersion heaters should have a wire coming from them, going to separate wall switches (often labelled on peak and off peak or something similar). For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 93

94 1.9 WATER HEATING All three of the following options are likely to be found in dwellings without a central heating system. They heat water on demand, rather than storing heated water. There is no need to specify a cylinder when entering any of these water heating options into the software. Electric, Instantaneous at Point of Use This type of water heater usually supplies, and is located next to, a single sink. They tend to be wall mounted or found under the sink and have a small store of 5 or 10 litres, though this can be bigger. A wall mounted switch indicates that the heater is powered by electricity rather than gas. Multi-point Gas Water Heater A multi point water heater heats water on demand and can supply a number of hot water taps in a property. They are similar in size to a boiler, but should not be confused with a regular or combi boiler. The front of a multi point gas water heater is usually quite simple, with one or two dials or a few buttons. Another way to identify a multi-point water heater is to turn on a hot water tap, which will fire up the heater (as it heats water on demand). This is similar to a combi boiler, except for the fact that it has fewer pipes. Common water heater brands include Chaffoteaux Britony II (pictured) and the Main Medway range. Single Point Gas Water Heater (instantaneous at point of use) These work in a similar way to the electric instantaneous water heater, providing hot water to a single tap. It is usually located in the kitchen or bathroom close to the sink. Gas boiler/circulator for water heating only Oil boiler/circulator for water heating only Solid fuel boiler/circulator for water heating only These three options are included in the water heating options so a boiler installed for heating water only can be specified. This option should only be used if the boiler cannot be identified as the 2nd Main heating system in the space heating section of the software. Range cooker If the water heating is supplied by a range cooker which is not providing space heating, it can be specified in the water heating section, the following options are available: gas, single burner with permanent pilot light gas, single burner with auto ignition gas, twin burner with auto ignition oil, single burner oil, twin burner solid fuel, integral oven and boiler soil fuel, independent oven and boiler The range cooker options available relate to the types of range cooker available as the main heating system. For more information on these types of range cooker please refer to the Space Heating chapter. Community heating If a dwelling has water heating only provided by community heating it can be specified in the water heating section. The following options are available hot water only community scheme boilers hot water only community scheme CHP hot water only community scheme heat pump These options relate to the types of community heating available as the main heating system. For more information about the types of community heating please refer to the Space Heating chapter. 94

95 Typical Vented System 1.9 WATER HEATING Feed and expansion tank Indirect hot water tank Boiler Mains Water For more information contact Stroma Certification at ext. 614 alternatively 95

96 1.9 WATER HEATING Water Heating System Components Hot Water Cylinder RdSAP requires information about the cylinder if one is present. Select one of the following options to record the cylinder size: Normal (90-130L) this is the most common cylinder size Medium ( L) Insulation Type select one of the following options None Spray Foam this type of insulation is applied during manufacture, the whole cylinder is coated providing good insulation to the cylinder. Jacket usually glass fibre insulation, not as effective as spray foam Large (>170L) most encapsulated cylinders are large capacity No Access if a cylinder forms part of the property s heating system but it is not accessible, the software will assume the insulation (based on the property age), and size (210L if off peak electric dual immersion, 160L if from solid fuel boiler, 110L otherwise). It is also assumed that a cylinderstat is not present When hot water is supplied by community heating from a communal tank it may be appropriate to average the cylinder capacity between all the dwellings it supplies. This means that a normal cylinder size can be applied to individual dwellings, rather than the large capacity. It may be necessary to determine cylinder size from cylinder dimensions. The table below can be used for guidance, but with experience you should be able to identify cylinder capacity based on a visual assessment. Jacket insulation Spray foam insulation Cylinder height in mm without insulation Cylinder diameter in mm without insulation

97 Insulation Thickness - one of 0, 12, 25, 38, 50, 80, 120, 160 mm. This is easily measured if jacket insulation. Spray foam insulation does not have many gaps; there is usually space for a tape measure where pipes join the cylinder. If the thickness measurement falls between two figures the lower number should be selected in the software. Please Note: if the jacket is loose fitting the thickness should be entered as less than 100mm to ensure a new jacket is recommended. Immersion Type (if appropriate) if the main water heating is selected as from immersion select one of single or dual Presence of Cylinderstat the cylinderstat is usually located about a third up from the bottom of the cylinder; typically held onto the cylinder with a coated wire. If the cylinder is insulated with a jacket the cylinderstat may be not be immediately obvious; the wire holding on the cylinderstat can be a useful clue to their presence. The cylinderstat must enable the user to control the temperature manually, usually with a small dial. Select either yes or no in the software to indicate the presence of a cylinderstat. An immersion heater has an internal thermostat to regulate its temperature, but this is not classed as a cylinder thermostat. 1.9 WATER HEATING For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 97

98 1.9 WATER HEATING Typical Unvented System Non-vented systems possess a few components which would not appear in a vented system Indirect hot water tank Expansion vessel Boiler Expansion vessel Mains Water 98

99 Modern Central Heating System More modern systems do not require header tanks as the system is pressurised and uses expansion vessels to modulate the pressure in the system. Although this type of system may appear very different to a traditional vented system, it makes no difference to RdSAP and must be entered in the same way. 1.9 WATER HEATING Expansion Vessel Usually located near the hot water cylinder, this is designed to hold the increased volume of water when it is heated (in place of the header tank in a vented system). Encapsulated Cylinder (Non-vented cylinders) Most modern cylinders have a plastic or metal case over the copper cylinder, which means it is not possible to access the insulation and not as easy to determine the capacity. Insulation - Spray foam insulation is installed between the cylinder and the outer case. We recommend checking the manufacturer s website to confirm the thickness of this insulation. If it is not possible to obtain manufacturer details, or this information is not available, then it can be assumed the cylinder has 50mm spray foam insulation Capacity - Encapsulated tanks vary in size; the capacity may be included in the manufacturer s details on the tank. If not, refer to the table earlier in this chapter Immersion Details - The immersion heater should be visible on the outside of the cylinder casing Cylinderstat - The cylinderstat should be located on the outside of the cylinder, about a third of the way up from the bottom. The stat should have a dial in order to manually control the cylinder temperature The manufacturer s website sometimes contains useful specifications relating to capacity, insulation and thermostatic control details. Common encapsulated tank manufacturers include Heatrae Sadia, Megaflo, Range Tribune and Santon Premierplus. Please Note: that some encapsulated cylinders can be quite old and are unlikely to possess much insulation at all. In this circumstance it should be assumed that there is no insulation. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 99

100 1.9 WATER HEATING Combined Hot and Cold Water Store Some properties do not have the space for a header tank. For example, in a block of flats it is not feasible to have a large number of header tanks in the loft space, due to the weight of all the water being stored. Combined hot and cold water stores (also known as Fortic tanks) are designed so that the header tank sits directly on top of the hot water tank and can be located in each individual flat. This type of water system does not provide very good water pressure. The cold water store should not be accounted for when determining the capacity or insulation for the tank. Thermal Stores Hot Water Mains Feed Cold feed Flow from boiler Return to boiler Some central heating systems incorporate a thermal store rather than a traditional hot water cylinder. The thermal store works in conjunction with the regular boiler to provide central heating and mains pressure hot water. The water heating should be entered into the software as from main heating system. A thermal store should be entered into the software as a cylinder with appropriate size and insulation for the make and model of thermal store. The insulation is likely to be 50mm spray foam insulation, as with an encapsulated cylinder. Old Square Tanks Immersion Heater Some older systems possess a square tank to store hot water, rather than a cylinder which is present in most systems. The tank is usually copper with some glass fibre insulation and a hard board outer case. This type of tank can be entered into the software as normal, with a suitable capacity selected. The insulation should be entered as jacket, rather than spray foam and it is normally possible to measure the insulation around the pipe work on the tank. Waste Water Heat Recovery System This type of system recovers heat from waste warm water from a shower and uses it to pre-heat hot water. It is difficult to retrofit this type of system, so they are only likely to be found in new builds, or where a bathroom has been renovated. In addition it is unlikely the system will be visible, therefore documentary evidence should be gathered. WWHRS must be included in database for them to be included in the survey. If the system is not listed it cannot be included in the survey, but its presence should be recorded in site notes. The type of system only works in conjunction with a mixer shower, where the hot water comes from a boiler, hot water tank or immersion heated. An electric instantaneous shower is not a mixer shower, and WWHRS cannot be included where only this type of shower is present. A mixer shower attached to bath taps is recorded as a mixer shower only if there is a permanent bracket over the bat and there is a shower curtain or screen. In order for RdSAP to determine whether a recommendation for WWHRS should be included, it is necessary to collect the following data in every property surveyed: Number of rooms with bat and/or shower (including rooms with an electric shower) Number of rooms with mixer shower and a bath Number of rooms with mixer shower and no bath 100

101 Solar Heated Water A property with solar heated water will have solar panels (pictured) or evacuated tubes. These are usually mounted on the roof, but they may be found on a south facing wall or in the grounds of the property. 1.9 WATER HEATING When a property has solar heated water, the Solar Water Heating box in the Water Heating section of the software should be ticked. No additional information is required, as the software will assume a surface area for the solar panel. (It is not necessary to take measurements for the panels). The solar heated water must be linked up to a hot water cylinder (either an additional cylinder to the existing water heating system, or a large capacity twin coil cylinder specifically designed for solar heated water). If the system has an additional cylinder the combined capacity of both should be noted, as it is not possible to specify two separate cylinders in RdSAP. Water Heating System with Solar Collector and Twin Coil Tank Solar Collector To Taps Flow from boiler Return to boiler Pump From cold water cistern For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 101

102 1.10 RENEWABLE TECHNOLOGIES Renewable Technologies This chapter will cover: Renewable Technologies which have not been previously addressed in this manual How to recognise the different technologies How they should be assessed and entered into the software There is a variety of renewable technologies: Photovoltaic panels Wind turbines Solar heated water (covered in Water Heating chapter) Heat pumps (covered in Space Heating section) Biofuel boilers (covered in Space Heating section) There are a number of ways of providing heating, hot water or electricity to a property using renewable energy sources. Unlike fossil fuels, renewable energy sources emit little or no carbon and are thus classed as Low or Zero Carbon energy sources

103 Photovoltaic (PV) Panels Solar panels generate electricity from solar radiation. The electricity produced is then fed straight into the home through the consumer unit. Some properties in remote locations that are off the grid, can be connected to a bank of batteries which will store the electricity produced. It is also possible to export electricity back to the national grid and receive a payment for the number of kwh exported. When recording PV, if the data is available then enter the kwp, orientation, pitch and overshading 1.10 RENEWABLE TECHNOLOGIES PV panels are typically mounted on a south facing roof to capture the maximum solar energy during the day The panels are usually dark blue in colour and may vary in thickness (although they are typically slimmer than solar heated water panels) Individual cells on a panel can be seen on close inspection PV panels are normally arranged in an array of linked panels covering an area of several square metres Some PV panels are integrated into roof tiles When surveying a property with PV panels, RdSAP requires the DEA to calculate the total roof area and the total PV panel area in order to determine the percentage of total available roof area covered with solar panels (this includes the main house plus any extensions). You can now enter up to 3 PV systems in RdSAP. To enter 3 different system you must know the details for all three seperate systems, e.g. if you have 2 out of the 3 systems you can only enter 2. This can also be utilised for a system that is on the different planes of the roof and only a single kwp figure is provided. In this case estimate the relative area of each and apportion the kwp accordingly. kwp this is the kilowatt Peak and should be included in the PV panel documentation. This figure should not be estimated, if it is not available you should only enter the percentage roof covered by PV. If the figure is available it should be included, and the orientation, pitch and Overshading must also be entered, these can be assumed in the absence of specific data. Orientation this is based on the points of the compass, you will need a compass to determine the PV panel orientation. Pitch the panels can be horizontal, vertical or at an angle of 30, 45 or 60 degrees select 30 o if unsure Overshading select from none, modest, significant and heavy select modest if unsure Wind Turbines Wind turbines can also be used to generate electricity for a property. In this case, the energy is usually stored in batteries due to the fluctuating nature of the way the energy is generated. Alternatively the system can be connected to the National Grid and the electricity generated can be exported, if not required at the property. In RdSAP the Wind Turbine is based on a model with a 2m diameter rotor and 2m hub height, which is often mounted on the side of a property. The effectiveness of a wind turbine is determined by the terrain type selected for a property, as this dictates the average wind speed assumed for an area, and therefore the amount of electricity generated. The software will make the provision for only one type of turbine to be entered. If however a property has two turbines that differ in both hub and rotor height, they must be combined and entered as one. There is a calculation spread sheet available on the members area which takes data of multiple turbine types and converts it into one figure. For more information contact Stroma Certification at ext. 614 alternatively domestic@stroma.com 103

104 RdSAP METHODOLOGY MANUAL Advice and information contained in this RdSAP manual is presented for general educational purposes. It is not intended to offer legal guidance and should not be used in place of consultation with appropriate professionals or reference to DCLG publications. Although this manual has been carefully prepared, Stroma does not accept any legal responsibility for the contents of the document or for any consequences, including direct or indirect liability arising from its use. We are not responsible for: errors due to inaccurate or incorrect data or information, mistakes in calculation, errors arising out of modification to this information, or errors arising out of incorrect use of this information. Stroma Certification consistently strives to improve its training materials and support documentation. If you have any suggested revisions which would make this document clearer, or if you have any suggestions for additional topic areas or issues that should be addressed in relation to RdSAP training, we would appreciate your comments and feedback. Stroma, 4 Pioneer Way, Castleford, WF10 5QU T: ext. 614 For further guidance on any element covered in the manual please contact the domestic technical support team, call extension 614, or domestic@stroma.com. As part of the Green Deal process, assessors can carry out an Occupancy Assessment in order to predict the energy demands of a household, based on the occupants' behavioural patterns and the energy appliances used. Stroma Certification s OA Software Module will predict these patterns, as well as potential energy savings and installation costs. A software manual is available to guide assessors through the various features of the software, and is available for Stroma members to download from Stroma Certification March 2013 RdSAP Methodology Manual Edition 2.0