bre rdsap manual v6.0 full

Energy Performance Certificates for Existing Dwellings

RdSAP Manual

Version 6.0 October 2009 BRE Train

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BRE RdSAP Manual Contents Introduction 1 Example EPC (England & Wales) 12 Survey Methodology & Practice 13 Ageing properties and elements 18 Identifying basic constructions 31 Dwelling details 43 Heating and hot water 79 Renewables, lighting and miscellaneous 113 Advice and recommendations 119

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© Building Research Establishment Ltd 2009 1

Introduction

Covered in this section: § A History lesson § What does the EPC contain? § RdSAP sensitivity and limitations of use

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Introduction Energy Surveys are about identification and conventions, with which we can achieve accuracy, consistency and repeatability.

A history lesson Two parallel strands: (1) energy labelling, (2) climate change and related policies Strand 1: energy labelling 1972 - 1979

• The oil crises – OPEC etc. – oil price quadrupled • Early work on low-energy houses, notably at the Open University in Milton

Keynes • First dabbling in ‘energy audits’ and ‘energy labels / ratings’ by academics

1986

• Energy World housing exhibition – Scandinavian standards 1989

• Birth of National Energy Foundation (NEF) out of Milton Keynes Dev Corp 1990

• Development, by NEF, of the National Home Energy Rating (NHER) 0 - 10 • Emergence of Starpoint energy label « « « « «

1991

• Development, by BRE for Government, of the Standard Assessment Procedure (SAP)

o Scale, 1 - 100 • Concept of ‘Authorised’ providers – FAERO (NES-SAVA, Elmhurst, MVM)

1995

• SAP calculation compulsory in Building Regulations • Initial pilots of energy ratings for existing homes, mainly by lenders

2002

• SAP display compulsory in new-build units

Strand 2: climate change and related policies 1992

• The UN ‘Earth Summit’, Rio – sustainable development 1997

• Kyoto protocol obligations (overall 5% reduction in GG emissions) • UK to reduce GG emissions 12½% from 1990 levels by 2008-12

2003

• Energy White Paper • Reduce CO2 emissions 60% by 2050, ‘real progress ‘ by 2020

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2006 • EU Energy Performance of Buildings Directive + enabling legislation (published

2002) o Required an EPC when a building is build, let or sold.

• Part L 2006 comes into force in April • Code for Sustainable Homes launched in December. The Code is intended as

a single national standard to guide industry in the design and construction of new sustainable homes (the Code has 9 categories).

o The Code is applicable to England, Wales (which requires Code level 3 for all new-build dwellings) and Northern Ireland. Scotland still uses EcoHomes.

2007 • FAERO ceases operation as an industry body which sets standards for the

energy rating of buildings, with CLG now directly taking responsibility for accrediting organisations and setting the standards to which energy assessors must comply.

2008

• A rating against the Code must be provided for all new dwellings from May 1st (although this may be a ‘nil-rated’ certificate) – social housing schemes are required to achieve code level 3 as a minimum to be awarded Homes and Community Agency funding.

2009

• DECC Heat and Energy Saving Strategy o Sets out an aim for emissions from existing buildings to be

approaching zero by 2050. highlights include: § All homes to have received by 2030 a ‘whole house’

improvement package § Comprehensive information and advice to be made available

to help people make changes to save energy and save money – including widespread availability of home energy advice by accredited advisers.

§ new ways to provide financial support so people can make more substantial energy saving and renewable energy improvements to their homes

The future:

• EPBD re-cast, considering o dropping of the 1,000m2 threshold for “major refurbishment” o a requirement for effective control systems and penalties for non-

compliance o a requirement to draw up national plans and targets for increasing the

number of low/zero energy and carbon buildings. § Policies and legislation from UK Government are inline with

these requirements.

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How can all this be achieved?

• National obligations and grants – CERT, Warmfront, Low Carbon Buildings programme, etc.

• Smart metering

– By 2020 smart meters for gas and electricity to be rolled out to all UK residential premises.

• Products policy

- e.g. minimum efficiency standards for heating pumps ‘Band C etc… - European Energy Efficiency Labelling Scheme e.g. A++ rated

refrigeration goods. - Compulsory phase out of traditional tungsten lamps for CFL and LED.

• Tightening of Building Regulations…

– Includes compulsory Energy Performance Certificate (EPC) for new-build (EPBD requirement) by January 2009

• will be issued using full SAP calculations (off plans, not survey) • National Occupational Standards for ‘On Construction

Domestic Energy Assessors’ – Part L 2010 will come into force in October 2010.

• Part L1a (new-build dwellings) requires a further 25% improvement in CO2 emissions.

• Part L1b (existing dwellings) – Conservatories under 30m2 to no longer be exempt – Exemptions on energy efficiency requirements for

historic, temporary, small buildings <50m2 TFA and buildings with low energy demands are to be removed – instead guidance on what constitutes reasonable provision is provided.

– Insulation standards are defined for swimming pool basins in existing dwellings.

– WER – band C windows and doors 1.8 W/m2K are minimum standard. Other U-values have been tightened up.

– The adoption of ‘consequential improvements’ still in debate.

• New compliance guides compliment Part L 2010 that set minimum efficiency standards for building services (e.g. A-rated boilers will become the minimum).

– New-build zero carbon by 2016; refurbishment by 2050.

• Housing Act 2004 – Requires compulsory EPC and improvement recommendations when

an existing home is let or sold (EPBD requirement) • when let? 1st October 2008 • when sold? via Home Information Pack – despite full HCR

now being voluntary – Who can provide this?

• Competent persons • qualified as HIs or DEAs (NOS are set for both) • BRE-approved software • Training by various parties (incl. BRE)

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What does the EPC contain? The EPBD dictates that it must contain performance indicators, benchmarks and recommendations. “Energy Efficiency Rating” is the SAP.

– Space and water heating; lighting – £/m2/yr, standard occupancy, mid-UK location – ‘SAP 2005’, 1-100, where 100 = energy self-sufficient but can go beyond

“Environmental Impact Rating” is the equivalent but based on carbon, not £. A full SAP calculation is too complex for mass assessments of existing homes, because it contains hundreds of input data items. Reduced Data SAP (RdSAP or RdSAP) was developed for the rating of existing dwellings only, it containing just tens of input data items plus extensive “inference algorithms” which automatically deduce the missing data. Scheme Operators will be expecting that 90% of EPCs to be within + or – 5 SAP points and that 100% of EPCs are within + or – 10 SAP points of the rating determined by the Scheme Operator’s Energy Assessor undertaking quality monitoring. For information: EPCs are valid for up to 10 years*, unless included in a Home Information Pack (HIP). When a dwelling is first put on the market, the EPC must be no older than 3 years. An EPC does not expire as such – it simply is no longer valid for the purpose for which it is to be used. For England & Wales the requirement for different types of EPCs and their current validity periods are provided in the following table:

Strand Date requirement comes into force

Validity period of certificate

EPCs for marketed sale of dwellings

Phased in between August and December 2007

Up to three years*

EPCs for non-marketed sale or rental of dwellings

October 2008 Up to ten years*

EPCs on construction of dwellings

6 April 2008 Up to ten years*

EPCs for commercial buildings (non-dwellings)

6 April 2008 for buildings over 10,000m2; July 2008 for those over 2500 m2; October for all others.

Up to ten years*

DECs for public buildings and related recommendation reports

Must be in place by October 2008.

One year. Advisory report is valid for up to seven years*

Air conditioning inspection reports

By January 2009 for large units; by January 2011 for others.

Up to five years*

* Unless there has been a material change or a more recent certificate/report.

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The fuel prices used within RdSAP software to produce Energy Performance Certificates are updated twice a year at the end of June and December, so that the running costs, savings and recommendations provided appropriate guidance to the reader. Latest Version of RdSAP • SAP 2005, revision 2

o SAP 2005 version 9.83, dated October 2009

o Incorporating Appendix S (RdSAP) • Download from

http://projects.bre.co.uk/sap2005/

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http://projects.bre.co.uk/sap2005

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RdSAP’s sensitivity to input data The RdSAP result is most sensitive to errors in the following: 1. Heating

– fuel – appliance – controls

2. Overall fabric heat loss (Σ A.U) – inferred from dwelling age, type and size

3. Hot water

– fuel – system – cylinder insulation – controls

Examples: Take a typical refurbished (well-insulated) mains gas-heated 1930s 3-bed semi with a SAP of 79. Now make the following errors (each taken individually):

– Record space heating fuel as ‘bulk LPG’, not ‘mains gas’ § SAP = 36 (down 43)

– OR record wall construction as ‘solid brick’ instead of ‘filled cavity’ § SAP = 59 (down 20)

– OR fail to notice cylinder jacket and cylinder thermostat § SAP = 67 (down 12)

Instead, make the following six simple errors all together, in the one house…

– record boiler as very old – fail to notice any space heating controls – record space heating fuel as bulk LPG – record wall type as solid – fail to record cylinder jacket – record water heating as electric immersion

…and the resulting SAP is 2 (i.e. down 77!) - but it does depend on house age, because of the changing ratio of space heating to hot water etc.

How is the advice produced? This is described in depth later in this manual, but essentially it involves yet more algorithms, and the resulting advice is ranked by simple payback. Surveyors must understand the basics (see the text on the Energy Performance Certificate itself!), and must use judgement to suppress the advice which is automatically generated based on the information the survey has provided when necessary.

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Energy assessment process Fundamentally, an Energy Performance Certificate must be produced whenever the law requires one to be produced, either as part of a Home Information Pack or independently. In England and Wales, the Government has decided that, for dwellings, the EPC and accompanying recommendations report (RR) must be produced by accredited Energy Assessors who will collect data and use approved software to produce them. For existing dwellings, the approved software will make use of the RdSAP (reduced data SAP) approach. Similar provisions apply for Northern Ireland and Scotland. A separate EPC is required for each dwelling. For a marketable sale a dwelling is required to have an address to provide the Home Information Pack (HIP), however additional EPCs can be produced for granny flats, converted garages and homes offices which are separate from the main dwelling (i.e. completely stand alone buildings with separate heating systems) provided that they are domestic use (otherwise RdSAP is not applicable) and part of the marketed sale. From 1st October 2008, all existing dwellings will require an EPC when sold or rented. All energy certificates should be produced using the relevant calculation tool specified in the National Calculation Methodology. This applies for all Energy Certificates whether on construction, sale or rent, or for public display. Information on new-build EPCs for reference (undertaken by on-construction DEAs only) Energy Performance Certificates (EPC) will be required on all newly constructed dwellings from 6 April 2008 as part of the Building Regulations, regardless of whether the dwellings will then be sold. This will apply both to 2006 build and pre-2006 build. Homes being marketed for sale ‘off-plan’ will require a Predicted Energy Assessment (PEA) in the HIP when first marketed, to be replaced by a full SAP EPC once the dwelling is completed. From 6 April 2008, all homes built and physically complete on or after this date, will need to have an EPC provided on construction. It is the responsibility of the builder to provide an EPC when a home is constructed and physically completed from 6 April 2008. This will also apply to any change of use to a new dwelling or if a building is converted into fewer or more units and changes are made to the heating, hot water provision or air conditioning/ventilation services. When the home is physically complete, the builder must obtain an EPC for the home, provide the EPC to the new owner of the home and notify the local authority building control officers or approved inspectors that this has been done. This must be done no later than the time specified by the building regulations. Building regulations include standards for the energy performance of new homes which builders must adhere to in order to comply with building regulations. Once building control are satisfied the EPC has been properly produced and provided to the relevant party, they are able to issue a final completion certificate. From 6 April 2008, a final completion certificate for a home cannot be issued by building control unless they are satisfied an EPC has been provided.

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When you finish your building work, Building Control asks you to submit a notice which includes an energy rating to demonstrate your building complies with the Building Regulations. By the same date on the notice, you must get an EPC from an accredited On Construction Energy Assessor, give the EPC to the owner of the building and quote the reference number (RRN) of the EPC to the building control. This is what you have to do under the Building Regulations, Approved Inspector Regulations and the Energy Performance of Buildings Regulations, and Building Control will not give you a final completion certificate until they are sure that everything has been done. For further information please view the following document: Energy Performance Certificates (EPCs) and New Homes - A Builder’s Guide Improving the energy efficiency of new homes. (www.communities.gov.uk/publications/planningandbuilding/epcsbuildersguide)

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http://www.communities.gov.uk/publications/planningandbuilding/epcsbuildersguid

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Assessment methodologies A number of different methodologies have been developed for different types of building and building condition. A summary is provided below:

Condition requiring a Energy Performance

Certificate Assessment Methodology

1. A dwelling on completion of construction

Full SAP assessment from architectural plans (to be undertaken by an on-construction DEA only) for all new dwellings from 6th April 2008.

2. Building not intended as a dwelling on completion of construction

SBEM or DSM (see below for details).

3. A dwelling being sold or rented out

RdSAP (unless the unusual nature of the building indicates that a more accurate assessment could be obtained using the full SAP methodology).

4. A building catering for mixed use (i.e. combining dwelling and non-dwelling) is constructed, sold or rented out

It should be treated as a single dwelling as described above if the commercial part can be converted back to residential use and there is common access i.e. each part does not have a separate access (for example, where within a house a portion has been separated out as a workshop, office, or surgery); For other scenarios, treat the dwelling and non-dwelling parts separately using the most appropriate methodology for each element. For example, where a building contains both flats and offices use SAP or RdSAP for the flat and SBEM or DSM for the offices.

5. For all other buildings being constructed, sold or rented out

SBEM or DSM.

6. When a Display Energy Certificate is required for public buildings

Operational Rating Methodology.

A Domestic Energy Assessor is only qualified to undertake RdSAP surveys for existing dwellings and thus provide EPCs for items 3 and 4 above. Additional training and accreditation is required to use the other assessment methodologies.

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SBEM - Simplified Building Energy Model SBEM is a computer program developed by BRE that provides an analysis of a building's energy consumption. The SBEM tool is designed to cover buildings that are not dwellings. It has been adopted by government as part of the UK national methodology for calculation of the energy performance of buildings. It is used to demonstrate compliance for dwellings with Part L of the Building Regulations 2006 (in England and Wales). For more information visit: www.ncm.bre.co.uk. DSM - Dynamic Simulation Model A Dynamic Simulation Model is a software tool that models energy inputs and outputs for different types of building over time. In certain situations, SBEM, will not be sophisticated enough to provide an accurate assessment of a building's energy efficiency. In these cases Government-approved proprietary dynamic simulation models may be used. Communities and Local Government will provide such an approval. Operational Rating Methodology New software for the calculation of the operational ratings for display energy certificates has been developed for the Government. It is important to note that the services in larger buildings are far more complex than those in ‘normal’ dwellings, and specialist surveying skills are required in order to assess them. The current guidance is that if a Home Inspector or Domestic Energy Assessor is not trained, qualified and accredited to use SBEM software then any commission which requires its use must be declined. Further guidance is expected as the conventions and systems become clearer.

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http://www.ncm.bre.co.uk

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Survey methodology and practice

Covered in this section: § Survey methodology § Measurement standards and rules § Requirements for site notes, sketches and

photographs

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Survey methodology Each inspector/assessor will develop his/her own surveying style and it is prudent to adopt an approach that suits you. However, a systematic approach, using pre-printed site notes form and good quality sketches with accurate dimensions should always be included. Photographs are also essential to ensure the accurate recording of the relevant features of the property on the day of the inspection/assessment. To produce an Energy Performance Certificate some 50 data items are required. Most of these questions are clear cut (yes/no), but the survey conventions must be adhered to as missing or incorrect information will most likely require another survey or questioning of the occupant. If a data item cannot be correctly identified then choose either ‘unknown’ or ‘as built’ (where applicable) and use local and personal knowledge where applicable. The energy efficiency recommendations are generated based on the information you provide, it is therefore very important that any problems which will prevent a specific energy efficiency improvement from being installed (e.g. rising damp & cavity wall insulation) are noted too. Correct identification is essential, otherwise the recommendations will not be reliable and the report will lose credibility. Basics first Safety – Conduct a risk assessment of the property before starting the inspection/assessment. Review your own safety as you move about the property. Expertise – when dealing with items which may be beyond your experience and expertise think carefully about the following where common errors can arise:

• Geographical locations • Property types • System types

Equipment – ensure you have all the relevant equipment to complete a thorough inspection/assessment of the property. Ensure you know how to correctly use, interpret, calibrate and maintain each item of equipment. This will include:

• Measuring device(s) • Moisture/damp meter (useful for purposes of Condition report if you are a

Home Inspector) • Ladder • Camera

See full list of equipment and requirements in the current version of the Inspection and Reporting Requirements (IRR) originally produced for Home Inspectors.

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Measuring standards and rules As an inspector or assessor you are required to take appropriate and accurate measurements. All measurements must be metric only. Standards Firstly some basic definitions:

• Houses/bungalows - Gross External Area (GEA) • Flats/maisonettes - Gross Internal Area (GIA)

Purpose of measurements For EPC calculations:

• Energy efficiency (RdSAP) – area. • Heat loss perimeter – linear. • Ceiling height – linear (always an internal measurement). • Room in roof – linear (always an internal measurement).

From these measurements the heat loss of the dwelling can be estimated Additional measures may be required for investigation and verification purposes. What and where to measure:

• Every level – floor by floor. • External: outer wall surface (measure to the mid-point of any party wall). • Internal: wall to wall – above skirting board. • Ceiling height – full (weighted average per floor). • Perimeter – full length (gross).

Accuracy – all measurements should be to the nearest 0.1m2. However higher precision is welcome and should be retained (especially for room heights where a 10cm difference for each storey can make quite a different to the volume of the building and hence heating requirement – try to record at an accuracy of 2 decimal places). See more detailed guidance within the ‘Dwelling details’ section. BRE Tr

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Requirements for site notes, sketches and photographs The Home Inspector or Domestic Energy Assessor is required to conduct the property inspection or assessment in a thorough and methodical way, recording details and taking measurement accurately – in order to produce a competent report. To achieve this it is recommended that the inspector/assessor will use and produce:

• Pre-printed site notes/form • Annotated site plan • Layout plans – every level • Photographs – external & internal

The purpose of taking and retaining photographs is to record the exact features present in the property on the day of inspection. Sufficient detail must be shown to demonstrate the structure, materials, build form, age(s), levels of insulation, and the heating and hot water types and fuel(s). Colour photographs are required for auditing purposes and provide important evidence to defend you against any complaints. A minimum of 8 to 10 colour photographs - 4 or 5 external and 4 or 5 internal should be taken and retained. More photographs would be expected for properties with a range of features, e.g. extensions, complex or varied layouts, room in roof or roof extension, alternate wall types, heating systems with disparate controls etc. A more detailed list of the range of photographs expected can be found in the guidance sheet on the next page. Only valid reasons for not taking relevant photographs:

• No access • Feature does not exist • Permission refused (interior only).

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Photographs required for the EPC

External Photographs External or Internal Photographs Internal Photographs

1. Front elevation(s), including roof 2. Rear elevation(s), including roof 3. Any feature(s) that help define age 4. Any extension(s) 5. Any roof extension/alteration(s) 6. Detail of ‘rooms in roof’ 7. Detail of wall structure/bond type 8. Detail of any cavity wall insulation drill

holes 9. Any alternative wall type 10. Any features that affects the heat loss

perimeter (integral garage/ passageway)

11. Detail of flues

1. Reason(s) for suppressing recommendation(s) e.g. evidence of dampness

2. Any limitation(s) on inspection 3. Gas / Electricity meter(s) 4. Detail of glazing type 5. Detail of any conservatory separation

1. Primary heating system a. Any boiler / heaters / fireplaces b. Any boiler make/model c. Any radiators/grills/underfloor

2. Any secondary heating 3. Heating controls

a. Programmer b. Any TRVs c. Any room thermostat d. Any zone control

4. Evidence of fuel source 5. Hot water heating (if relevant)

a. Cylinder size b. Insulation type & thickness c. Any thermostat

6. Loft insulation (if relevant) a. Location / thickness / material

7. Low energy lights 8. Any solar hot water heating 9. Any PV panels

Each photograph should be labelled to describe: Feature – relevance – location (e.g. Gas boiler – primary heating – kitchen cupboard) Only valid reasons for not taking relevant photographs:

• No access • Feature does not exist • Permission refused (interior only).

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Ageing properties and elements

Covered in this section: § Ageing properties and elements § Typical features and thermal performance

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Age band Identify age band separately for:

• main property • any extension(s) • rooms in roof (separately for main dwelling and any extension)

Select the age when built - any improvements made after this time which improve the performance of the property, such as adding cavity wall insulation, should be specified later in the survey form. If a house has undergone complete refurbishment, then select the age band when building control approval was granted. From the 1960s, constructional changes have been caused primarily by amendments to building regulations for the conservation of fuel and power, which have called for increasing levels of thermal insulation. The dates in Table S1 in SAP Appendix S are generally one year after a change in regulations, to allow for completion of dwellings approved under the previous regulations. e.g. a house built in 1996 is more than likely to have received approval under the 1995 regulations and it should be entered in the earlier age band. Where a property or extension could be in either of two consecutive age bands and you are in doubt, always select the earlier of the two age bands by default. Estimating age band The task of estimating the age of a dwelling is not an easy one. It is therefore necessary to approach the task in as systematic manner as possible, and to make use of as wide a range of information as possible. It should be borne in mind that dwelling types vary enormously from region to region and from town to town, and there are quality differences according to the class of residents for whom they were built. Care must be taken not to confuse the style and materials used in subsequent, often extensive, modifications to the original structure. Some knowledge of the construction methods, typical materials, component designs, and design styles popular at different times over the past 100 years or so helps. It should be remembered however that this is not foolproof (some post-war dwellings were built to inter-war designs; some element replacements are undertaken in an older style to preserve the look of a building; unfashionable treatments are sometimes used for economy or to achieve a particular performance). The key age bands required for the RdSAP methodology for England and Wales are as follows:

• Pre 1900 • 1900 - 1929 • 1930 - 1949 • 1950 - 1966 • 1967 - 1975 • 1976 - 1982 • 1983 - 1990 • 1991 - 1995 • 1996 - 2002 • 2003 - 2006 • 2007 onwards.

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(different age bands apply for Northern Ireland and Scotland, please refer to SAP 2005 Appendix S) Each of these age bands are profiled in turn below, with examples of different age bands of properties typical to England and Wales. If the dwelling is a conversion prior to April 2008 (i.e. complete renovation like a barn conversion), then use the age band for the conversion, not the original build date. If the conversion is not whole house conversion then the dwelling should be recorded as per the original age band, but with the individual improvements to insulation or heating systems recorded separately. Any conversion undertaken after April 2008 for the purposes for EPC would be classified as a new dwelling and must require a full SAP assessment by an On-construction assessor – therefore RdSAP assessment cannot be used.

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Pre-1900 Medieval and other pre-Georgian buildings should be readily identifiable in most cases, but in town locations earlier timber framed buildings often lie behind later brick facades. Georgian, Regency and early Victorian houses were characterised by their distinctive classical proportions. Facades generally lack detailed ornamentation, often being unified by stucco or paint. Larger houses tended to have applied classical orders in the form of columns, pilasters, pediments, cornices, rusticated lower walls and lintels and occasionally wrought ironwork. Windows and doors were usually spaced singly and were flat headed or rounded, the windows invariably being sashes with smallish panes. Roofs were generally low pitched, sometimes hipped and on the main elevation were often hidden behind a parapet. Lintels were often of rubbed brick on the external 4.5 inches, and wood on the inner 4.5 inches. Window and door reveals were sometimes rendered and painted. Internally, the larger houses had servants’ quarters in a basement and/or in a small attic or non-shared back addition. Early houses often used narrow or non-standard bricks and before 1870 lacked site concrete and damp proofing. Mid and late Victorian dwellings were characterised by their more elaborate decorative features. Facades tended to have more detailed ornamentation than the equivalent pre 1850 dwellings, the ornament being generally integral with the structural fabric, typically using contrasting ornamental brickwork or stonework at the edges of the façade or to pick out the windows and doors. Fired clay building components were used (both unglazed terra-cotta and glazed), as was reconstructed stone (for example in lintels). Decorative features often had a mainly gothic/medieval origin, as with indented cornices; except in the Queen Anne Revival style where classical features were introduced as well. Doors and windows were often arched, typically with a flat segmental arch. As well as being in bays, which were generally square or angular, windows were increasingly combined and although they were

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still sashed, they had fewer panes. Roofs were steeper and generally visible, often having gables and attic dormers in the larger houses. Ridge tiles were often crenellated. The use of cavity walls began but remained rare throughout the period. Internally, basements were less frequent; the servant quarters being confined to larger, often higher and often shared back additions. The introduction of stricter building bye-laws gave more regularity, with walls in the main part being 9 inch minimum and floors being of the suspended timber type. During this period, streets of terraced houses were often given names associated with the Crimean War – Inkerman Rd., Balaclava Rd., Stanley Rd., Victoria St. During this period, the first social housing created by the charitable trusts began to appear, followed by pioneering local authorities, such as London County Council. Such housing was almost invariably in the form of four or five storey blocks of flats, with communal staircases and access galleries. Usually, construction was of load bearing brick but less orthodox building elements such as filler joist floors and steel on cast iron joists and concrete columns are often found.

1900 – 1929 Edwardian houses and villas were characterised by their broader, more solid proportions. Facades tended to be more heavily ornamented than in the 19th century, but the ornament was often applied rather than integral with the structural fabric. Timberwork, tile hanging, the use of glazed tiles and terracotta, albeit found in the 1890s, were more frequently used, together with roughcast and Art Nouveau decoration. Doors and windows were broader, with sashes being subdivided for ornamental reasons with leaded lights. Roofs tended to be slightly less steep but incorporated sometimes even larger gables and more ornamentation such as timber finials. Clay finials and elaborately moulded ridge tiles were also used. Wall tiling up to dado level was often used in the recess at the front entrance. This was sometimes extended through into the entrance hall, which tended to be rather grander than the rest of the interior. Decorative, often black and white, floor tiles

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were also used in the entrance hall. Sometimes stained glass was used in the front door. Internally, the dwellings tended to be wider; the rooms were larger but tended to be fewer in number with somewhat lower ceilings. With the increasing use of daily help and the consequent demise of the servants’ quarters, back additions became smaller or less segregated, a greater emphasis being placed on the use of the back rooms and garden. Nearly all houses had a DPC and often had airbricks which ventilated the suspended floors, whilst the occasional use of cavity walls continued. During this period, streets of terraced houses were often given names associated with the Boer War – Kimberley, Ladysmith, Mafeking and so on. etc.

1930-1949 During this inter-war period, styles changed dramatically. The most common form was semi-detached pairs; terraces were occasionally used for the smaller houses, but these rarely comprising of more than 4-6 houses. This was the period of the growth of the large suburban estates (Metroland) around the major cities, built at low density with substantial semi-detached dwellings set in private plots. Non-traditional building was introduced. Local authorities made quite extensive use of non-traditional building techniques involving steel frame, timber frame, in-situ concrete and precast concrete. Such houses were often brick clad or rendered, and can prove hard to identify. An unusual wall thickness (not 9”, 220mm) or the loft inspection can provide clues to their construction. After 1930, new local authority housing was virtually confined to inner city slum clearance schemes, usually in the form of 5-story walk up gallery access blocks. These flats were generally of loadbearing masonry construction but some examples of steel framed blocks exist in the major cities. Walls were usually brickwork, or a combination of this with rough-cast rendering. Windows were often of the wooden side hung casement type, but were sometimes of metal. Each opening casement usually contained several panes of glass, separated by glazing bars, rather than single panes. Bay windows

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were quite common. Roofs of inter-war period houses tend to be hipped, rather than gable ended. They were sometimes covered with slates and sometimes with tiles. Internally, the original doors were usually panelled; skirtings and architraves were moulded or bevelled.

1950 - 1966 Properties of this period may sometimes be more difficult to distinguish from those from the 1930-49 period. Semi-detached pairs remained quite popular but – in council estates particularly – terraced housing became fairly common. Walls were usually brickwork, or a combination of this with various types of rendering. Occasionally, timber boarding, tile hanging or concrete panels were used. Window openings generally became wider than they were high; panes of glass tended to fill complete casements and large picture windows, of proportions hitherto unseen, became popular. Bay windows were less common than in the earlier periods. Roofs were usually tiled and rarely slated. Some roofs, where flat or low pitched, were covered in bituminous felt (usually having a green or grey grit surface). Roofs were usually gable ended, but occasionally hipped. The immediate post-war period saw a massive investment in local authority housing which made considerable use of non-traditional forms of construction. Woolaway dwellings were constructed during the 1950s. Most of these houses are relatively easy to identify because of their non traditional cladding and roofs but some brick clad and rendered types are less easy to identify (see BRE non-traditional guide for assistance).

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1967 – 1975 Design styles in this period are less well-defined than in previous periods, and no specific characteristics stand out. A wide range of semi-detached and detached dwellings prevails, with roof construction covering all forms of gabled, hipped and, for a time, monopitched roofs. Roofs making use of concrete tiles are of a lower pitch than in earlier periods. During the immediate post 1964 period a number of high and low rise blocks of flats were built in a variety of types of construction – loadbearing brick, steel and concrete frame, and large concrete panel construction. Various low-rise systems, some using timber, some steel and some concrete for the frame were also used for large numbers of dwellings. These were clad in a variety of finishes, but brickwork still predominated. This period saw the introduction of new materials on the outside of dwellings, plastic gutters replacing asbestos cement, to be followed by plastic sidings. Windows were generally of the side hung casement type, but occasionally pivots, either vertical or horizontal, can be found. Towards the end of the period plastics became more widely used in window design, with casements predominating, although tilt and turn patterns following continental practice were also introduced. Heating of dwellings began to change radically following the passing of the Clean Air Act in 1956, with central heating by fuels other than solid heralding a reduction in the number of dwellings having conventional chimneys. At the beginning of the 1970s the architectural styles grew from the sixties look. Inserts in the outer brickwork in the form of vertical or horizontal panels (of tile hanging, timber, composite sheet) were used to give a visual connection between largish windows, and to provide coherence for the building as a whole, even though it might be a terrace of single family homes. Fencing within the site, or on balconies was of wide timber planks (painted or stained) on metal posts: together with the wide white painted fascias, these tended to emphasise the overall ‘look’ of ‘connectiveness’.

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1976 - 1982 and 1983 - 1990 Very difficult to distinguish between adjoining age bands. If still fitted with original windows – will likely be wide wooden frame and strange proportions of glazing. When the thermal insulation requirements for external walls were increased in 1975 (the move from brick-brick to brick-block cavity walls) and window design tended to change from generous proportions to the smaller sizes. Internally, doors are normally flush pattern, and skirtings and architraves very plain with either a chamfered or rounded profile. The ceilings are plasterboard, painted or with an Aertex finish, sometimes with a coving at the junction of ceiling and walls in the principal rooms. Social housing – around 1975 A number of pressures were at work on social housing during the seventies. The reaction against high rise living increased the proportion of single family dwellings in most schemes. Where flats continued to be built, these tended to be on a more human scale: there was also a greater concern for landscaping immediately around the dwellings and a tendency to group buildings in an attempt to reproduce small scale street forms. An increasing disillusion with more extreme forms of industrialised building led to dwellings looking more like traditional housing forms even though they might use system elements such as timber frames. The growing concern for energy conservation, and its operation through building regulations, led to smaller widow sizes and the use of brick and block construction with cavity insulation. The rejection of large scale demolition and renewal and the emphasis on rehabilitation, together with the parallel growth in housing associations, led to mixed schemes combining new build with rehabilitation, which reinforced the general move towards single family homes. The housing cost yardstick was having a greater effect in paring down external decoration and detail. By the middle of the decade the windows had begun to get smaller: they tended to be ‘sprinkled’ over the external brickwork and no attempt was made to

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connect them visually. This meant the individual dwellings within a block or terrace tended to look more ‘separate’. The overall effect was of a more spartan appearance, relieved only by the odd tiled sloping roofed ‘porch’. By the beginning of the 1980s attempts were being made to add some decoration to the basic form from the mid seventies. Lines of different colour bricks were used to outline or connect widows and doors, and simple ‘filligree’ iron work was being used for fences, balconies, and supports for projecting parts of the building. Bays and Oriel windows were used to provide further relief to the external brickwork.

1991 - 1995 Through the 1990s, the trends begun during the 1980s continued. Decoration became ever more eclectic, allowing different shaped windows, more grandiose porches, more intricate iron work.

Recent changes to building regulations has meant the inclusion of several recent age bands: § 1996 – 2002 § 2003 - 2006 § 2007 onwards

Smaller size – due to planning constraints. Check any warranties. Ask the occupant!

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Typical features and thermal performance Pre 1900 typical features

• Detached houses but more terraced houses in mid to late Victorian period • Suspended timber floor construction • Solid load bearing brick walls (220mm) U-value 2.1 • No damp proof course • Un-insulated pitched roof U-value 2.3

1900-1929 typical features

• Principally terraced housing • Suspended timber floor construction • Solid load bearing brick walls (220mm) U-value 2.1 • Damp proof course • Un-insulated pitched roof U-value 2.3


• Mainly semi-detached houses • Un-insulated solid concrete floor construction • Brick : Brick cavity walls becoming more common

– Solid load bearing brick walls (220mm) U-value 2.1 – Brick cavity walls (250mm) U-value 1.6

• Damp proof course • Un-insulated pitched roof U-value 2.3


• Semi-detached with terracing or high rise common in council housing • Un-insulated solid concrete floor construction • Brick : Brick cavity walls (250mm) U-value 1.6 • Damp proof course • Un-insulated pitched roof U-value 2.3


• Semi-detached with terracing more common in council housing • Un-insulated solid concrete floor construction • Brick : Brick cavity walls (250mm) U-value 1.6 • Insulated pitched roof (12mm) U-value 1.5


• Semi-detached with terracing more common in council housing • Un-insulated solid concrete floor construction • Brick : Concrete Block cavity walls (260mm) U-value 1.0 • Insulated pitched roof (50mm) U-value 0.68


• Semi-detached with terracing more common in council housing • Un-insulated solid concrete floor construction • Brick : Concrete Block insulated cavity walls (270mm) U-value 0.6 • Insulated pitched roof (100mm) U-value 0.40

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• Semi-detached or terraced predominate • Un-insulated solid concrete floor construction • Brick : Concrete Block insulated cavity walls (270mm) U-value 0.6 • Insulated pitched roof (150mm) U-value 0.29


• Semi-detached or terraced predominate • Solid concrete floor construction insulated (25mm) • Brick : Concrete Block insulated cavity walls (300mm) U-value 0.45 • Insulated pitched roof (150mm) U-value 0.26


• Detached or linked predominate with increase in private flats • Solid concrete floor construction insulated (75mm) • Brick : Concrete Block insulated cavity walls (300mm) U-value 0.35 • Insulated pitched roof (250mm) U-value 0.16

2007-0nwards typical features

• Detached or linked predominate with increase in private flats • Solid concrete floor construction insulated (100mm) • Brick : Concrete Block insulated cavity walls (300mm or thicker)

U-value < 0.35 • Insulated pitched roof (250mm+) U-value 0.16 or less.

A number of small changes with successive building regulations can lead to a significant increase in energy efficiency and reduced U-values over time.

Typical Pre-1900 dwelling Typical 2003-2006 dwelling

• Detached houses but more

terraced houses in mid to late Victorian period

• Suspended timber floor

construction • Solid load bearing brick walls

(220mm) U-value 2.1 • Un-insulated pitched roof

U-value 2.3

• Detached or linked predominate

with increase in private flats

• Solid concrete floor construction insulated (75mm)

• Brick : Concrete Block insulated

cavity walls (300mm) U-value 0.35 • Insulated pitched roof (250mm)

U-value 0.16

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External features that can help to age a property: • Appearance or style of construction • Number and size of windows and doors • Construction materials • Roof coverings • Chimneys • Finishes

Internal features can help to age a property or extension:

• The style of kitchen fixtures and fittings • The style of bathroom fixtures and fittings • Presence and style of fire places • Size and detail of skirting boards

Original kitchen and/or bathroom fittings can help confirm or narrow down the age bands. This may be more relevant for the more modern properties as over time fixtures and fittings may have been replaced. Beware of reproduction styles.

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Identifying basic constructions

Covered in this section: § Traditional construction § Non-traditional construction § Modern Methods of Construction (MMC)

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Traditional construction The majority of houses/bungalows and many low-rise flats in Britain are of brick or brick and block wall construction, with pitched/sloping timber roofs. Solid wall construction was common from the 1800s to 1950. Cavity wall construction was introduced as early as 1900 in some areas but predominates from 1935 to the present day.

Solid walls: Pre 1850 to 1950. Cavity walls: 1935 to present. Be aware of different mixes of header and stretcher bonds that require closer inspection to determine if a cavity is present and if the cavity has been insulated retrospectively.

Both the above walls are of cavity construction and both show drill holes where the cavity has been filled with injected insulation. Additional information on construction types in the ‘Ageing properties and elements’ and ‘Dwelling details’ sections.

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Non-standard construction Definitions and further sources of information Included here are all constructions other than solid or cavity brick and/or block wall construction. Essentially they include: 1. ‘Non-traditional Houses’ – systems built between 1918 - 1980:

• Metal framed • Pre-cast concrete • In-situ concrete • Timber framed

Note: Both timber frame and system built are often described as non-traditional construction but they have different energy performances and are therefore identified separately in RdSAP. 2. Modern Methods of Construction (MMC) – Dwellings constructed from the mid 1990’s, whose structural parts are wholly or in part manufactured off-site or on-site by contemporary methods. It includes complete housing systems built in factories through to new, site-based technologies. Identifying non-traditional and modern methods of construction Identifying specific construction types, whether non-traditional or modern methods of construction, can prove difficult. As such if you encounter a construction type that is unfamiliar to you then you should seek further advice. BRE have published several key publications to assist surveyors in identifying construction systems:

• BRE Report 469 Non-traditional houses: identifying non-traditional houses in the UK 1918-75 (below left).

• BRE Report BR282 Timber frame housing 1920 -1975: Inspection and Assessment.

• BRE Report BR113 Steel framed and steel clad houses: Inspection and Assessment.

• BRE CD ROM AP149 Non-traditional housing. A collection of 82 previously published reports and leaflets on specific types of non-traditional houses.

• BRE Trust FB11 Modern methods of house construction by Keith Ross (below right).

REMEMBER – know your limitations, if this is not your area of expertise then do not accept instructions for these types of dwellings without further specialist training. Refer to the BRE website www.bre.co.uk/training for training courses or contact the team via email [email protected].

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Designated Defective A number of specific non-traditional dwelling types have been designated defective under the 1984 Housing Defects legislation (now part XVI of the Housing Act 1985) these are listed below.

Non-traditional dwellings - Designated Defective List • Airey • Ayrshire County Council • Blackburn Orlit • Boot Beaucrete • Boot Pier and Panel • Boswell • Cornish Unit Type I • Cornish Unit Type lI • Dorran • Dyke • Gregory • Mac-Girling • Myton • Newland • Orlit Type I • Orlit Type II • Parkinson • Reema Hollow Panel

• Schindler • Smith • Stent • Stonecrete • Tarran Temporary Bungalow • Tee Beam • Ulster Cottage • Underdown • Unitroy • Unity Type I • Unity Type II • Waller • Wates • Wessex • Whitson-Fairhurst • Winget • Woolaway

Expect these types of dwellings to be over-clad and show other signs of remedial works.

Cornish Unit Type 2: semi-detached – left half over-clad.

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Types of non-traditional construction Metal framed Principally these comprise steel framed (or steel and cast iron based) system built dwellings. About 140,000 such dwellings have at some time or other been authorised for construction in the UK, and many different kinds of system have been used. In addition to the steel systems there were a small number of aluminium framed dwellings constructed. The majority of metal framed dwellings would have been constructed for local authorities, with many subsequently passing into private hands. Few records remain with local authorities as to their location however BRE Report BR113 ‘Steel framed and steel clad houses: Inspection and Assessment’ includes a useful list of locations. Some dwellings date from the interwar period but the majority date from the post Second World War period. This reflects the need for rapid re-building after the war and to a certain extent the availability of materials and manufacturing plant no longer directed to wartime production. A common feature of many systems is that the finished dwelling was made to look as close as possible to conventionally built dwellings, with the preferred finishes either brick, imitation brick or render. Some of these disguises are nearly perfect and it takes more than a superficial examination to discover that some dwellings are indeed metal framed. On the other hand, some are immediately obvious as being of un-conventional design e.g. BISF Houses. If it is not obvious that the house is metal frame then the roof space is often the easiest place to confirm the construction type. The gable or flank wall normally comprises unlined sheathed metal framing, with the separating wall of metal stud framing, lined with plasterboard. It may also be possible to see the top of external wall panels at the eaves from within the roof – where loft insulation does not preclude access. Sometimes it is possible to identify construction within service cupboards where linings have not been installed.

Type 3 first floor BISF Type 3 first floor Riley It is important to note that the cavities of metal clad houses should not be filled; external insulation should be used instead. Where cavities are filled there is an increased likelihood of corrosion caused by condensation.

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Pre-cast concrete It is reported that around 284,000 dwellings in England have concrete panels as their predominant wall structure. The earliest being constructed during the 1920s but the majority being constructed during the 1950s and 1960s There are essentially two types of pre-cast concrete dwelling system:

• Panel systems • Pre-cast concrete on concrete framing

Panel systems – These essentially involve producing flat reinforced concrete panel units in a factory and transporting them to site for assembly. The structural panels are then stacked on pre-prepared foundations to typically form room or flat sized boxes. Panels being supplied for use as walls, intermediate floors and roofs. Panels used as external walls may have the concrete textured or have an external finish such as brick, tile, paint or sheet material applied to provide an aesthetic finish. Widely used in high rise developments they were also used for low rise housing. With low rise developments it was common to use the concrete panels to create a ‘toast rack’ of separating walls and to use alternative materials for the external walls to the front and rear of the property. Internally concrete panels were usually wet plastered but some will have been dry-lined. Note that there are 23 different large panel systems used in the UK to construct buildings with 4 or more storeys. Pre-cast concrete on concrete framing – In a large number of cases the external appearance of the dwelling will immediately indicate that it is a pre-cast concrete system built house as the frame and panels are left exposed. However a small number of systems were rendered externally during construction. Typically the systems comprise a concrete frame with storey height infill panels. The infill panels comprise pre-cast concrete panels which span either vertically or horizontally between the concrete frame. In most cases the infill panels are slotted so that they engage with the frame. Most systems were two storey and featured pitched roofs, but there are some three storey Cornish Unit blocks and most Orlit houses had flat roofs.

Cornish Unit Type 1 Cornish Unit Type 2 Be aware that different types can look almost identical – note the similarities between the Cornish Unit Type 1 and Gregory houses.

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Gregory In-situ concrete Cast-in-situ concrete was used extensively as an alternative to brickwork during the inter-war period. A number of different systems of cast-in-situ walling were developed with the intention of lowering costs by reducing construction time. Subsequent analysis suggests that they were in fact more expensive to build than using traditional methods. There are several basic types of cast-in-situ construction:

• Single leaf walls with removable formwork • Single leaf walls with permanent formwork • Cavity walls consisting of precast concrete slabs with cast-in-situ concrete

columns • Cavity walls, consisting of precast concrete slabs with a cast-in-situ concrete

core • Cavity walls with removable formwork

The concrete mixes specified included dense and clinker aggregates largely dependent on local sources. The most prolific system was the Wimpey no-fines system of which some 300,000 dwellings were constructed between the 1940s and 1970s. No-fines concrete is a non-proprietary material used extensively in Britain for the construction of both non-loadbearing and loadbearing walls in dwellings. No-fines concrete contains no sand fraction, and often has a single size stone as sole aggregate constituent. This produces a honeycomb structure in concrete which gives it a higher thermal insulation (lower U value) than that of dense concrete. System type Number built Concrete thickness

Wimpey 300,000 8", 10" or 12" SSHA 25,000 8" - 10" Unit 4,350 8" Easiform Type I 2,100 8” Corolite 700 8" Foamed slag 200 9" Lamella 183 Miller temporary bungalow 100 8" Weir 100 10" In most cases in-situ concrete house walls were constructed as a single leaf and internally were wet plaster finished.

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Wimpey no-fines Timber framed These are dwellings in which the loads from upper floors and roof are carried by and transmitted to the foundations by a timber frame. The claddings are generally non-load bearing and concentrate on providing weather protection and appearance. There are essentially four types of timber frame construction:

• Balloon frame – two storey height or eaves-height external wall panels, with studs continuous from ground floor to roof.

• Platform frame – storey-height external wall panels which are erected upon platforms formed by the ground and upper floor construction.

• Post and beam – a structural frame of widely spaced timber posts and beams. Planked, joisted or panelled floor and roof units span between beams, and non-load bearing infill panels span between the posts to form the external wall claddings.

• Volumetric box – assembled from three dimensional room-sized or storey–width prefabricated units (see also modern methods of construction)

Between 1920 and 1944 about 8,000 timber frame dwellings were built for the UK public sector with a further 100,000 built between 1944 and 1975. Numbers increased in the private sector during the1960s and 1970s. However, timber-frame lost favour in the 1980s to conventional brick and block construction. Since the late 1990s they have made something of a come back. Systems built prior to the Second World War were mostly timber-clad and are readily recognisable as being of timber frame construction. By contrast, many post war systems, particularly those built in the 1960s and 1970s, have brick claddings and are not easily distinguishable from other types of construction of the period. Even so, in most cases there are particular features that indicate the existence of timber frame construction. The claddings used for timber frame dwellings include brickwork, tile hanging (horizontal or vertical) and rendering. These may be used singly throughout or more often across a dwelling. With brick cladding the windows tend to be set back in the reveals, and there may be small gaps or soft packing beneath the window frames, under the eaves and at the tops of verges in order to accommodate differential movement between the cladding and framing. Internally, external walls are dry-lined, usually with plasterboard nailed directly to the timber framing. However those built immediately post war were often lined internally with fibreboard, possibly fixed over timber boarding.

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Scotwood rendered plywood timber frame 1980s rendered block timber frame As the Domestic Energy Assessor can only carry out a non-invasive inspection of a property you are likely to be limited in how to identify a timber-frame dwelling. The roof space is often the easiest place to confirm the construction type. The gable or flank wall normally comprises unlined sheathed timber stud framing, and the separating wall is of timber stud framing, lined with plasterboard. It may also be possible to see the top of external wall panels at the eaves from within the roof – where loft insulation does not preclude access. Sometimes it is possible to identify construction within service cupboards where linings have not been installed. The lining can sometimes be distinguished from dry-lining to a masonry wall by tapping the lining just above a window: timber frame walls usually have timber lintels which sound less ‘hollow’ than other types of lintel.

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Modern Methods of Construction The term ‘modern methods of construction‘ (MMC) covers a broad range of construction types ranging from complete housing systems built in factories through to new, site-based technologies. Older terms such as ‘system building’, ‘off-site construction’, ‘industrialised construction’ and ‘modular construction’ are still used by many. A simple classification of modern methods by built form is:

• Volumetric construction • Panellised systems • Hybrid construction • Sub-assemblies and components • Site based methods of construction

The first four categories are usually manufactured in a factory. The term ‘site based methods’ covers systems that do not fall neatly into the first four categories. Volumetric construction This involves the production of three-dimensional units in a factory. The units are transported to site where they are stacked onto prepared foundations to form the dwellings. A typical house is made from four units, whereas flats are usually formed using two units or with smaller flats a single unit. All of the necessary internal finishes, services and, potentially, the furnishings can be installed at the factory, with the complete entity transported to site and assembled. Some external finishes can be applied in the factory (for example brick slips), but usually some work is required on site in order to make good between units. To date most volumetric construction has been used in the hotel, student and key worker accommodation, healthcare and fast food sectors, however this method of construction is now being introduced to housing. Panellised systems This involves producing flat panel units in a factory and transporting them to site for assembly. These can be constructed in a variety of materials and constructions ranging from framed panels in timber or steel, to concrete and composite panels such as SIPs (structural insulated panels). Panel systems are referred to as ‘open’ or ‘closed’. Open panel systems are framing systems (metal or timber) delivered to site before insulation, services etc. are fitted. Closed panel systems are more complex and can have services, windows, doors, internal wall finishes and external claddings fitted at the factory. Hybrid construction This method of construction involves a combination of volumetric and panellised construction. Typically three dimensional volumetric units are used for the highly serviced areas such as kitchens and bathrooms with the remainder of the dwelling constructed with panels. They can include a mix of construction and material types with steel framed volumetric units and timber-frame panellised elements.

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Sub-assemblies and components From the point of view MMC, this applies to innovative constructions for floors and roofs that use engineered products such as timber I beams or lattice joists, which might be installed on site as prefabricated cassettes. It does not include factory produced sub-assemblies and components such as door sets, windows, stair strings etc. which have been used in factory manufactured or traditionally built dwellings for some time.

Site based methods of construction This category relates to site-based assembly methods and the use of traditional components in an innovative way. This includes Tunnelform (cast-in-situ concrete using heated steel moulds), aircrete planks and thin joint blockwork. Other innovations include the use of brick slips, insulating formwork and single leaf masonry.

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in-situ concrete polystyrene permanent shuttering

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Dwelling details

Covered in this section: § Recording general information about the

property § Survey conventions

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Type of assessment and location. From the 18th October 2009, all domestic EPCs will additionally show the “Type of Assessment” on page 1. The three possible types are:

• SAP, new dwelling. • SAP, existing dwelling. • RdSAP, existing dwelling.

When producing an existing dwellings EPC using approved RdSAP software the last of these options ‘RdSAP, existing dwelling’ will be automatically included on the EPC. You must also record the location of the survey (England & Wales or Northern Ireland) and if the EPC is to be issued in English or Welsh (England & Wales only).

Related party disclosure The DEA must declare any relationship with the parties referred to below:

1. No related party. 2. Relative of homeowner or occupier of the property. 3. Residing in the property. 4. Financial interest in the property. 5. Owner or Director of the organisation dealing with the property transaction. 6. Employed by the professional dealing with the property transaction. 7. Relative of the professional dealing with the property transaction.

Transaction type The transaction type indicates the reason why the EPC was initially undertaken. This is for statistical purposes only and does not affect the calculated results or restrict the use of the EPC. Select the most appropriate type for an existing dwelling: Transaction Type Description

1 – marketed sale Properties sold through conventional means. This includes all EPC commissions from estate agents and similar.

2 – non marketed sale Change of ownership but not through marketed sale. This includes right-to-buy and the large scale voluntary transfer of local authority housing stock to a registered social landlord. Otherwise this option should rarely be used.

3 – rental (social) Properties owned by local authorities, social landlords that are registered with the Housing Corporation (most are housing associations, but there are also trusts and co-operatives).

4 – rental (private) Rented properties not owned by organisations at 3.

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5 – not sale or rental Property not being sold and not for rental market. For example, a house owner might have improved the property and wants to lodge an improved EPC. An EPC is not required by the regulations under these circumstances and so lodgements under this category are expected to be extremely rare. Note that if the property is a rented one, it should always be transaction type 3 or 4 irrespective of the circumstances.

6 – new dwelling A dwelling that has not previously been occupied. Mainly newly construction homes assessed off-plan using SAP. This will also apply if a building is converted into more or less parts, where changes are also made to the heating, hot water provision or air conditioning / ventilation. If a non-domestic property, such as a barn or warehouse, is converted into a home or homes, this is classified as a new dwelling. In these circumstances a full SAP EPC will be required.

Option 6 is only available for new dwellings using full SAP software.

Terrain type The terrain surrounding the property is used for evaluation of wind turbines. It must be entered in all cases to enable consideration of a wind turbine as a possible further improvement measure.

• Dense urban – dwellings located in city centres with closely spaced buildings of four storeys or more.

• Suburban – dwellings located in low rise areas of

a city with buildings well spaced. Also applies to towns and villages.

• Rural – dwellings located in open country side

with occasional houses and trees.

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Built form The built form classifications are self-explanatory and you should select the option that most closely describes the built form of the property. A flat of maisonette are treated the same in terms of the EPC assessment, but the option selected should best fit the description of the marketed sale. These different features are modelled within the energy calculations so choosing the wrong classification will estimate the heat loss incorrectly and could also cause problems with data entry/processing of the Energy Performance Certificate. Bungalows are generally more expensive to heat as they have a greater amount of heat loss area per m2 of useful floor space.

Detachment

• Detached. • Semi-detached. • Mid-terrace

o has two external walls (front and back). • Enclosed mid-terrace

o has an external wall on one side only (typical for back-to-back terraces).

• End-terrace o has three external walls.

• Enclosed end-terrace o has two adjacent external walls.

Terraced dwellings with a passage way is not an explicit option – if a passage way is present it is actually accounted for within the floor area measurements (the first floor area will be greater than the ground floor area – the difference is an exposed floor for the upper storey, which the program will account for). Staggered terraces, or link detached, should be recorded as the most appropriate of the above detachment options with the true exposed wall area being accounted for within the heat loss perimeter measurement for each storey. Also note the differentiation between an end-terrace and a semi-detached property. Whilst these are, on sight, of the same built form, there is a difference in the way in which the RdSAP software calculates window areas for the two built forms since end-terrace houses are often built to the same specification as the associated mid-terrace properties and therefore have either less or no window area on the extra exposed wall.

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Flats and maisonettes Additional questions are asked for flats and maisonettes: Q. Floor level? i.e. which storey is the flat located on such as second storey flat, or ground floor flat. A ground floor is recorded as ‘0’. If the property is a maisonette with a ground floor entrance the rules for porches/draught lobby’s should be followed. Basement flats should be entered as per ground floor flats (i.e. recorded as ‘0’, and the other floors from 1 upwards.). Q. How many floors in block? A count of the total number of floors in the block of flats. The floor level recorded cannot exceed one less than the total number of floors in the block. This question is asked because the higher the flat is located the greater the exposure and heat loss. Q. Heat loss corridor?

• No corridor • Heated corridor • Unheated corridor – additionally record the length of the sheltered wall

If the corridor is heated, but the heating system is not part of the flat then it is disregarded and the wall adjacent to the heated corridor is not included within the heat loss perimeter (i.e. the option ‘heated corridor’ should be recorded). If a heated corridor is present and the heat is provided by the heating system of the flat/maisonette (i.e. a radiator fed by that particular flats boiler, or a on-peak room heater which the flat occupant pays for) then that area is included within the main dwellings area with any heat loss perimeters measured and recorded appropriately. Q. Heat loss floor type? Floor type needs to be recorded as one of the following:

• Above another dwelling • Above partially heated space (e.g. shops, workspaces or other non-domestic

premises) • Above unheated space (e.g. above garage or other space which is not

habited) • Fully exposed (e.g. above driveway). • Ground floor.

Where the flat is above more than one type, it is classified according to the largest floor area concerned.

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Floor perimeter

• For flats & maisonettes always take internal measurements (for obvious reasons)

• Don’t mix measurements – take measurements all internally or all externally (the floor area and perimeter of room(s)-in-roof are always measured internally - irrespective of the dimensions basis for other storeys).

Number of habitable rooms This is a simple count of the number of habitable rooms in the dwelling and any extensions:

• Include any living room, sitting room, dining room, bedroom, study and similar; and also a non-separated conservatory. A kitchen/diner having a discrete seating area also counts as a habitable room.

• Excluded from the room count are any rooms used solely as a kitchen, utility

room, bathroom, cloakroom, en-suite accommodation and similar; any hallway, stairs or landing; and also any room not having a window.

A lounge/dining room where the door was temporarily removed (i.e. architrave and hinges still there) is counted as two habitable rooms. For open plan dwellings count all spaces thermally connected to the main living area (e.g. a living/dining room) as one room. For example, a lounge/dining room with the door permanently removed (hinge holes filled etc…) is 1 habitable room. A lounge/dining room where the door was temporarily removed (i.e. architrave and hinges still there) is two habitable rooms. For a kitchen to be a kitchen/diner it must have space for a table and 4 chairs. For rooms to be counted as habitable they must have a permanent means of access within the dwelling i.e. a doorway or stairs (so for rooms within a loft conversion to be counted a permanent a set of stairs is required, as per building regulations), with natural light and means of ventilation. A heated room is one with a fixed heat emitter within the room. In addition to the above:

• The number of habitable rooms which have a fixed heater emitter should be recorded on the survey form (for inadequate heating purposes).

Background information The habitable rooms questions are important as they are used to define the ‘living area fraction’ of the dwelling which is calculated internally within RdSAP software. RdSAP assumes that the living area fraction is heated to 21OC (i.e. living rooms etc.) and with all other areas being heated to 18OC (i.e. bedrooms). These values are the demand heating temperatures which RdSAP uses to calculate fuel use and running costs for the EPC (among other things, such as fabric heat loss).

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Extensions

Extension age band? • Ask the occupier • Contact local building control • Informed estimate based on

style • If same age, wall and roof type

then record as main dwelling.

Extensions with different insulation standards or different characteristics (e.g. wall or roof) from the main dwelling are recorded separately. The extension must also be a heated and occupied area of the house to be recorded. Recording the different characteristics will then allow the RdSAP software to assign the correct U-values and attributes. If an extension has the same age, construction and insulation as the main dwelling, then you don’t need to record it separately – treat it as a part of the main dwelling. Tips • Sketch details of the extension on the field sheet and add up areas separately. • ‘Sun rooms’ should be recorded as extensions. • Only two extensions can be recorded. In this case of more than two extensions

the surveyor should add together the floor areas and exposed perimeters of extensions (or add extension to dwelling) to reduce to two extensions. They should be combined according to the most similar age band. The alternative wall data entry option can be used as appropriate.

• Sometimes it is convenient to divide a house into main and extension for

recording its geometry, for example when part of it is normal 2-storey and part is single storey with roof rooms above.

Extensions over garages To process a first storey extension above a garage the extension must be recorded as being on the lowest occupied level (i.e. ground floor) otherwise the RdSAP software will return an error. The result may be slightly less accurate as the extension floor exposed to the unheated garage will be assumed to have a U-value of a floor exposed to soil as opposed to air (this effect is very, very minimal overall however). It should be noted on the survey form and site sketches that it is actually a first storey extension along with the appropriate heat loss perimeters.

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Porches/draught lobby A draught lobby/porch is an arrangement of two doors that forms an airlock on the main entrance to the dwelling.

Conservatories A conservatory is a structure with at least three-quarters of its roof and at least half its external walls glazed. A conservatory Not a conservatory

The above is commonly referred to as a ‘sun room’.

Q. Conservatory Type? All conservatories must be recorded whether they are thermally separated from the main dwelling or not by answering this new question. Select one of the four possible options:

• No conservatory • Separated, no fixed heaters • Separated, fixed heaters • Not separated.

If a conservatory is thermally separated, the presence of fixed heaters is recorded by selecting either ‘separated, no fixed heaters’ or ‘separated with fixed heaters’. This will influence the inclusion of additional text in the final EPC but not any calculations.

If heated always include (if separated or not) If external and not heated, disregard. If internal, not heated and thermally separated, disregard.

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A non-thermally separated conservatory is also included in the calculation by recording its floor area and perimeter. Q. Non-separated Conservatory? Thermal separation between a dwelling and a conservatory means that they are divided by walls, floors, windows and doors which are of external quality (i.e. same performance as other exposed elements within the dwelling). Where no thermal separation is present the floor area, presence of double glazing, glazed perimeter and conservatory room height must be recorded on the ‘Non-separated Conservatories’ section of the survey form. Tips for completing the non-separated conservatory data collection: • Floor area – should be based on either internal or external dimensions –

consistent with what the inspector has chosen earlier in the survey. • The glazed perimeter for the conservatory should be measured in the same way

as measuring the heat loss perimeter for the main house or extension. • The conservatory room height is estimated from the equivalent number of storey

heights of the dwelling to the nearest half storey (based on average internal height within the conservatory). Example of room heights for a conservatory on a side of a building:

Great accuracy is not required as this is a visual estimation of conservatory height - but in the above diagram the arrow is in the correct position of the average storey height (taking into account the ridge/pitch of the roof).

Swimming pools Indoor swimming pools cannot be modelled in SAP. However, if the pool is within the main area of the dwelling, this are should be recorded and treated as a habitable room. If the pool is located in a conservatory or extension then you record these parts as per usual. Outdoor swimming pools and swimming pools external to the thermal envelope of the building are not considered. Addenda The DEA must select the following addendum within the RdSAP software so the EPC produced will clearly state how the swimming pool has been treated: 4. Dwelling has a Swimming pool. Text included on EPC “The energy assessment for the dwelling does not include the energy used to heat the swimming pool”.

1 st

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1.5

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Rooms in the roof Rooms in roof can be either an original feature or a subsequent loft conversion. To be included within the assessment they must have a permanent fixed staircase such as one is able to walk downwards facing forward (i.e. stairs, not a ladder). Different types of room in roof can be found: 1. True room in roof 2. A separate storey with continuous external walls which are less than 1.8m in height 3. Combination of both True room in roof. These can be of different construction, but they are always built into a roof. Floor area of a “true room in roof” is normally smaller than floor area of the storey below. Walls are normally of a different construction than the main walls. Example: True room in roof – Floor area of a “true room in roof” is normally smaller than floor area of the storey below.

Typical constructions of true room in roof

True room in roof is always entered as “Room in roof”.

• The extra heat loss due to dormer windows is disregarded, but the floor area

measurements should take into account any extra floor area provided by the inclusion of dormers.

• Disregard party walls for the purpose of defining rooms in the roof

Ground floor

Room in roof

Ground floor

Room in roof

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• Remember to record a separate age-band for the room in the roof. • Always measure internally.

A separate storey with continuous external walls. A storey which has continuous external walls, but the external walls are not of the full height (i.e. 2.4 m). Such storeys normally have pitched roof. Floor area of storeys with continuous external walls is normally the same as the floor area of the storey below. Example: Separate storey – external wall or stud wall is 1.8m or more in height. Continuous external walls may be quite high (e.g. about 2 m) or very low (e.g. 1 m). If continuous external walls are low, then most of the storey performs like “room in roof”. The following “1.8m rule” should be used to decide whether the upper most occupied level should be entered as a “room in roof” or as a “separate storey”. Record the storey in question as a ‘room in roof’ if it has external walls or stud walls of internal height less than 1.8m (this refers to walls toward eaves, not gable ends or party walls). Record the storey in question as a ‘separate storey’ if it has external walls or stud walls of internal height 1.8m or more (this refers to walls toward eaves, not gable ends or party walls).

Remember to record a separate age-band for the room in roof. The 1.8m rule is not applicable in the case of a “true room in roof”

Height 1.8m or more, treat as separate storey

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In many cases it is not straight forward to make a decision on how to record a storey in question. In such cases the following recommendations should be used:

Recommendation 1. If a flat is solely a type of ‘room in roof’ then it must be recorded as the lowest occupied level, with the room height being specified as 2.20m and the heat loss perimeter recorded as it exists. The wall construction will usually be selected as timber frame, with any significant gable wall or ‘cold’ party wall of a different construction type recorded using the alternative wall type. This approach is necessary because the RdSAP software can only process a room in roof when it is accessed from another storey.

Recommendation 2. Full storey height room built into front or rear part of roof, so that it extends half of the dwelling to an additional storey while half of roof space remains as roof space or is converted into room in roof with sloping ceiling (see photo below). Treat as a separate storey with a room height of 2.20 m. Record floor areas measured internally.

Flat

Original gable wall

Original pitched roofNew flat roof

Added storey

Original gable wall

Original pitched roofNew flat roof

Added storey

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Recommendation 3. Where an upper storey in a dwelling is part a ‘room in roof’ and part a full-height storey (as shown below), it is better to split the dwelling in to two parts even if they are the same age and otherwise have the same thermal characteristics.

The floor area of the room in roof is always measured internally and recorded in the ‘room in roof’ sections of the software. The heat loss perimeter of the main dwelling is the perimeter of walls excluding length of wall between main dwelling and room in roof.

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Recommendation 4. Record the part of the house with the room in roof as the main dwelling with a room in roof – remember to age both parts. Record the two storey part of the house as a two storey addition (Extension 1 – same age as main). Record the part of dwelling above the garage as a ground floor extension (Extension 2 – with relevant age).

Exposed perimeter

Extension 2(recorded as ground

floorextension)

Main dwelling Extension 1

Ground floor

Exposed perimeter

Disregardgarage in

Extension 2


Upper floor

Area of room in roof

Exposed perimeter

Extension 2(recorded as ground

floorextension)


Ground floor

Exposed perimeter

Disregardgarage in

Extension 2


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Floor area The floor area for each storey of the dwelling and that of any extension should be recorded on the survey form. Horizontal dimensions can be measured either internally or externally. Internal dimensions are permissible in all cases. In the case of a house or bungalow external dimensions are usually more convenient, except where access to all sides of the building is not possible or where there are differing wall thicknesses or other aspects that would make the dimensional conversion unreliable. When using external measurements for a dwelling joined onto another dwelling (semi-detached and terraced houses) the measurement is to the midpoint of the party wall. Flats and maisonettes are usually measured internally (although it is not a requirement of the specification that internal measurements are always used). The floor area heated basements are always measured internally – thus in dwellings with a basement all measurements must be taken internally. When undertaking internal dimensions measure between the inner surfaces of the external or party walls. Any internal elements (partitions, internal floors, walls, roofs) are disregarded. In general, rooms and other spaces, such as built-in cupboards, should be included in the calculation of floor area where these are directly accessible from the occupied area of the dwelling. However, unheated spaces clearly divided from the dwelling should not be included. The floor area must not include any:

(a) Integral or adjoining garage (unheated) (b) Stores, coal sheds or other unheated spaces (c) Conservatories which are thermally separated from the main dwelling by an

external door (d) Roof voids, such as lofts accessed through a loft hatch or storage spaces

behind stud-work in rooms in the roof (even though within the insulated envelope i.e. where the roof insulation is provided at rafter level).

No special treatment should be given in cases where a central heating boiler is located in an unheated garage (i.e. just because the boiler is located in an unheated space you wouldn’t therefore count the space as heated despite the garage receiving some background heat due to the operation of the boiler). On the survey form, the floor area for rooms in the roof is differentiated from that of other storeys as the room height and heat loss perimeter are not required for rooms in the roof. The floor area is important for providing the client with guide costs for improvements and savings.

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Heat loss perimeter

• Exposed wall perimeter length for each storey including those adjacent to unheated corridors, service or lift shafts, conservatories which are thermally separated from the dwelling, integral or adjoining garages, car ports etc.

• The heat loss perimeter length is used to calculate the wall areas • It must be measured accurately so that wall areas can be calculated (to

nearest 0.1m or better). • If surveying a flat or maisonette don’t forget the heat loss corridor questions • Perimeter lengths adjacent to soil receive no special treatment and are

included within the heat loss perimeter (see ‘basements’ section for more information)

Note: When measuring areas and heat loss perimeters include all perturbations (e.g. bay windows and heated porches) but disregard chimney breasts unless the assessor considers them significant (e.g. large inglenook).

Room height The measurement should always be taken internally from floor surface to ceiling surface. For dwellings with more than one storey the RdSAP software will automatically add 0.25m per storey (for the intermediate floor), this intermediate floor area is then used within the RdSAP software to calculate the total heat loss through the exposed façade (the room height is multiplied by the heat loss perimeter). The room height is important for distinguishing between buildings with high and low ceilings; they have very different external wall areas and total volume for the same floor area.

• Treat mezzanine floors as though the intermediate floor continues as per a normal storey.

• Where the upper rooms extend into the roof space then the wall height is defined up to the level of the wall plate or the internal angle between the wall and sloping ceiling/roof

• Measure to the nearest 0.1m or better. Where both the main dwelling and the extensions have varying ceiling heights you should record them separately with the correct room heights. Where there are more than 2 extensions, or the room heights vary throughout the dwelling (as shown in the large complex house pictured) - due to the fact that only 2 extensions can be recorded - a ‘weighted average’ room height will need to be calculated. The extensions with the most similar age bands and construction types being modelled as one part (use Appendix S as a guide).

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Most modern dwellings will have a height of 2.40m. Older properties may have ceiling heights up to 2.90m or as low as 2.30m.

Basements Include when accessed via a permanent fixed staircase such that one is able to walk downwards facing forwards and either:

• Basement is heated via fixed heat emitters, or • Basement is open to the rest of the dwelling.

Measurements are recorded on the survey form as per a normal storey – ensure you do not mix internal and external measurements. If the basement is unheated and closed off from the main dwelling, then it must be disregarded. Perimeter lengths adjacent to soil (for example in the case of basements) receive no special treatment and are included within the heat loss perimeter, the wall length adjacent to any basement next door should be assessed according to whether the adjacent basement is heated (usual in the case of a basement flat) or unheated. Houses which are built into a hill side, and have walls adjacent to soil rather than air, also receive no special treatment and are recorded as if they where fully exposed to air.

Garages Garages are disregarded if they are thermally separated from the dwelling and unheated. However, you should remember to include any semi-exposed wall length to unheated garages within the heat loss perimeter of the main dwelling. If garages are heated then they are included in the assessment. Consider the construction of the wall area separating the dwelling from an unheated garage. If a different construction to the main dwelling and of sufficient size, include as an alternative wall type. No special treatment should be given in cases where a central heating boiler is located in an unheated garage (i.e. just because the boiler is located in an unheated space you wouldn’t therefore count the space as heated despite the garage receiving some background heat due to the operation of the boiler).

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Roof types To be recorded separately for the main dwelling and any extensions. In most cases it is easy to identify the roof type:

• Pitched (slates or tiles) - includes hipped ends and 'lean to' roofs and pitched roofs where the two slopes are shared between neighbouring properties. HI/DEAs must also specify whether it was possible to access the loft space

• Mansard or Chalet roofs are also modelled as pitched

• Thatched

• if an equal mixture of pitched and flat roofing is present you could choose to

record an extension as being present to allow this to be modelled

• Small areas of roof coverings (e.g. over a bay window) which differ from the main roof type can be disregarded.

Mansard - This is a dual pitched roof, with the steepest pitch (non-vertical walls of at least 70o pitch) which frequently contains windows at the lower section. If the upper section of a mansard roof is flat, this is not treated as a separate part of the roof structure. This is all part of the mansard roof component but when completing the roof covering, part can be made up of a different material, i.e. felt or metal. A mansard roof type:

Chalet - This is a pitched roof where the eaves come down to the ceiling height of ground floor level rooms. It often contains purpose designed rooms in the roof space. Flat – if the pitch is 10o or less.

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Thatched roofs – There is a separate entry for thatched roofs that takes into account the insulating benefits of the thatch. If insulation is present at joist or rafter level, then this should also be recorded. A thatched roof:

Dwelling above – this option should be used when there is another property directly above, such as in the case of a mid-floor flat within a block of flats.

Roof insulation Recording the level of roof insulation is very important as it has a significant effect on energy use. There must be evidence for joist, rafter or flat roof insulation; otherwise "unknown" should be selected. Pitched roofs Insulation can be present at either rafter, joists or both. There must be evidence of insulation, either measured if the loft space is accessible or documentary if loft space is inaccessible.

• If accessible, the thickness of joist insulation should be measured. A weighted average should be taken if the insulation is uneven, or missing in some parts.

• If joist and rafter insulation is present record the joist insulation only. • Rafter insulation should be included on the survey form • When inaccessible, or loft is boarded out, insulation should be recorded as

‘unknown’ unless there is documentary evidence. • For rigid insulation boards & other insulant types, enter as equivalent amount

of mineral wool (see equivalent thickness note below) Flat roof Flat roof insulation is often inaccessible and therefore cannot be measured.

• HI/DEA should record insulation as ‘unknown’ unless there is documentary evidence. The software will assume the thickness of insulation based on the age band of the property.

• If there is documentary evidence to prove that the flat roof has been replaced or retro-fitted with insulation, then ‘flat roof insulation’ should be selected.

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Room in roof Room in roof insulation applies to the vertical timber stud walls, sloping ceiling and flat part of the ceiling. RdSAP assumes the level of insulation based on the room in roof age-band, however in some instances, retro fit insulation can be added to the whole room in roof envelope or in some instances only to the flat part of the ceiling. In order to take into account the correct insulation levels, the following rules should apply.

• If the room in roof is an original feature of the property or is a loft conversion, the age-band of the room in roof should be entered and the insulation selected as ‘unknown’. The software will assume the level of insulation based on the age-band of the room in roof.

• When only the flat part of the ceiling is insulated, usually ascertained by way of a loft hatch, the option ‘flat ceiling only’ should be selected and the insulation thickness entered.

• If retro fit insulation has been installed on all of the room in roof elements then the option ‘all elements’ should be selected and the thickness of insulation on the flat ceiling specified. If there is no flat ceiling, such as in the case of a cathedral type roof, ‘not applicable’ should be selected for the flat roof insulation thickness.

• The insulation thickness for options ‘all elements’ and ‘flat ceiling only’ must be measured or have supporting documentary evidence that proves insulation has been installed.

Notes A weighted average is calculated as follows: 1. 70% of the loft space has 100mm of mineral wool 2. 30% of the loft space has 50mm of mineral wool = [(percentage of loft area1 * depth of insulation1)+ (percentage of loft area2 * depth of insulation2)] / 100 = [(70*100)+(30*50)]/100 = 85mm (however only 75mm can be selected in the survey, so round down to this) The weighted average is quite crude, but a pragmatic approach. Equivalent thickness Please see the Energy Saving Trust guide ‘CE71 - Insulation Materials Chart - Thermal Properties and Environmental Ratings’ available from www.energysavingtrust.org.uk

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Insulation in ‘rooms in roof’ and between rafters Currently RdSAP software assumes the level of insulation installed between rafters based on the age-band. However the assessor should record the thickness of insulation where visible as RdSAP software may be updated to allow the actual thickness to be entered. Documentary evidence Acceptable documentary evidence includes certificates, warranties, guarantees and building regulation submissions. The assessor should be confident that the installation was installed and that the documentation relates to the actual property being assessed.

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Wall types

Solid wall (pre 1850 – 1950) Recognised by the pattern of brickwork: the bricks are placed both head-on and lengthways (including Flemish, English, garden wall etc. bond types). The total thickness of the wall is usually about 225mm.

Cavity wall (1935 – present) Stretcher bond. Total thickness about 300mm.

• Solid wall category assumes a 9" brick

o Single brick should be recorded as a solid wall (i.e. record according to wall type irrespective of wall thickness)

• Stone wall category assumes a 20" to 36" thickness.

• 3 different types of stone wall can be selected

o ‘Granite or whinstone’. Whinstone is common in Scotland it is a quartz-dolerite, which looks very similar to basalt and is grey or black. Granites are volcanic rocks as well and can be pink to dark grey or even black.

o ‘Sandstone’

Like sand, sandstone may be any color, but the most common colours are tan, brown, yellow, red, grey and white.

o ‘Cob wall’ Cob wall consists of a mixture of earth, straw and sand that can be sculpted similar to that of clay. Due to its sculpting properties, cob walls can be curved with arches and niches. Unrendered cob walls are generally an orange/ brown colour.

Timber frame Disregard the cladding type when recording timber frame dwellings. Timber framed dwellings can be clad in timber, brick or a variety of other façade material, however each of these façades has very little effect on the thermal performance – this is why they are disregarded. Timber frame can be identified by:

• Looking inside meter boxes • Looking at the gable whilst in the loft space • Presence of plasterboard on internal wall (if dabs are present, then it is not a

timber frame wall)

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System build/non-traditional/modern methods

• select ‘system built’, if the structure has a cavity that is filled or unfilled this can be recorded.

• BRE’s Non-traditional handbook can be consulted. When faced with a mixture of wall types: Many dwellings have an extension either added onto the main part, or built at the same time but of different construction or insulation. In these cases, dimensions and constructional details of the main part of the dwelling and the extension are recorded separately, to allow the assignment of different U-values to the original and to the extension based on the age band and features recorded. Occasionally there may be two extensions whose details need each to be recorded separately. In addition, dwellings can have a different construction for some parts of the walls (for example, a bay window which incorporates a large area timber frame wall in otherwise masonry construction). These are recorded as a separate constructional element, termed "alternative wall". If an alternative wall is present, the area of the alternative wall is recorded excluding any openings in it and the alternative wall is identified as part of the main wall or extension wall, so that it may be subtracted from that wall area prior to the calculation of wall heat losses. If more than two alternative walls are present, assume the majority type. Note: Small areas of alternative wall area (for example 2m2 area next to a meter box) can be disregarded and just use the main wall type. For an alternative wall to be modelled it would be of greater area, for example, a whole wall next to a garage. The area entered in the ‘alternative wall area’ box should exclude windows. In other words, it is just the area of actual wall, you should deduct the area of any windows in that wall. When a wall type does not correspond to the available options the nearest equivalent type should be used for the assessment and documentary evidence recorded. SAP Appendix S contains information on U-values assumed. Addenda The DEA must ensure that the following addendum is selected in RdSAP software so the EPC produced will clearly state how a wall type has been dealt with if it does not match one of the wall options in RdSAP: 1. Wall type does not correspond to options available in RdSAP. “The dwelling has a type of wall that is not included in the available options. The nearest equivalent type was used for the assessment.”

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Wall insulation Record separately for main dwelling and any extensions.

• The internal dry-lining and external cladding options assume that a layer of insulation has been added to a wall which originally didn't have it, otherwise ‘As built’ should be recorded.

Identifying internal and external insulation Internal insulation is difficult to identify as it will be covered by plasterboard – internal insulation will only be applied to the external or heat loss walls, so it should be possible to see where the insulation (either rigid foam boards or timber/steel studwork) have been returned against a party wall. Other giveaways could be the fact that the wall thickness internally is now thicker. Obviously anything which is wet plastered is unlikely to be internally insulated, as plasterboard will always be used. Internal insulation in a bay window, comprising 2 rigid insulation boards which makes the window sill thicker. Note junction with wall. An example of internal insulation (mineral wool batts) being applied between steel C-sections and plasterboard being fixed to the steel studs. External insulation is relatively easy to identify, it will usually be wet rendered, dry clad (i.e. timber) or more recently perhaps even have brick slips applied.

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An example of a block of apartments which have been externally insulated (in Germany but the same principles apply in the UK). Note that the dwelling stands proud of the other adjoining properties and also has a higher roof due to the incorporation of external insulation. External insulation is usually visible at points around the dwelling (in this case around a soil pipe). Please visit www.energysavingtrust.org.uk/housingbuildings/ and read the publication CE184 ‘Solid wall insulation of existing dwellings’ for further guidance

• Select ‘filled cavity’ if cavity wall insulation is present (as indicated by presence of injection holes in mortar joints, or mineral wool/urethane foam visible in meter box, air bricks etc…)

• When cavity wall insulation is not a retro-fit measure – selecting either ‘as

built’ or ‘filled cavity’ will still produce the correct result. Examples of cavity wall insulation drill holes

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Where it can be established that a building element has insulation beyond what would normally be assumed for the age band, this can be indicated if adequate evidence exists. Evidence can be: • what is observed in the site inspection (e.g. loft insulation, rafter insulation, cavity

wall insulation), and/or • on the basis of documentary evidence. Acceptable documentary evidence includes certificates, warranties, guarantees, building regulation submissions. The assessor should be confident that the insulation was installed and that any documentation relates to the actual property being assessed.

Floor types The HI/DEA should try to identify construction of a ground floor during the survey where possible. The three floor types that can be entered are solid, suspended timber, and suspended (not timber). If the HI/DEA is unable to establish the floor construction then ‘unknown’ should be entered.

• Solid – consists of a concrete slab with a concrete screed finish. • Suspended timber –consists of timber floor boards supported on timber floor

joists with a ventilated air space below. • Suspended (not timber) – Any other type of suspended floor with a ventilated

underfloor air space. For example a concrete beam and block floor. There are several methods that a HI/DEA can apply to identify the floor construction, one of which is to look under areas of carpet or linoleum, that are not fixed down, to see if the floor surface is solid concrete or timber floor boards. A common place where floor coverings are not secured down are in cupboards, particularly in the case of suspended timber floors where there will be a hatch leading down to the under floor space. If the floor coverings are fixed down and cannot be easily lifted, the HI/DEA must not attempt to pull the coverings up. Suspended timber and concrete floors will also have under floor vents located on the external walls, just above ground level.

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It is also possible to identify a suspended timber floor by the presence of creaking floor boards.

Floor insulation To be recorded separately for main dwelling and any extensions. There are three options that can be entered for ground floor insulation, these being unknown, as built and retro-fitted.

• Unknown – in most cases this will be selected. • As built – confirms that no additional insulation has been added to the original

floor construction. • Retro-fitted- allows for situations where insulation is present in a floor, either

added subsequently to its construction, or incorporated in the floor when not required by building regulations during its construction. Documentary evidence is required.

Retro-fitted floor insulation is usually done by either suspending mineral wool in-between floor joists using netting whilst the floor boards are up, or in the case of a solid concrete floor insulation is commonly laid onto of the existing screed – this creates a rise in floor height.

Solid floor insulation raises the floor height – in this picture a raised area at the bottom of the stairs makes up the difference between the new finished floor level and the first tread of the original staircase Often internal doors will also be of different heights to incorporate the raised floor level.

When unknown or as built are selected, the insulation levels for the floor are based on the age band of the property.

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Windows Information on window area, type of glazing and the proportion that is double glazed is gathered for the whole dwelling, including any extensions and rooms in the roof, but not non-separated conservatories, where you should enter the glazed perimeter separately. Dormer windows, Velux type windows and glazed roofs in extensions or ‘sun rooms’ are included within the estimation of window area and type. You need to record the percentage of windows which have multiple glazing. This is a simple visual estimation, with no need to take measurements. Window area "Typical" refers to normal construction for the property type and age band concerned. By selecting ‘less than’ or ‘more than typical’ the RdSAP software will adjust the window area by +/- 25%. Window areas more or less than typical arise when windows have been added or blocked up subsequent to the dwelling's original construction. After this information has been provided the RdSAP software calculates the window areas automatically based upon the built form, main age and main/extension total floor areas. Window areas may be measured and entered individually in ‘extreme’ cases when:

• A dwellings window area is more than +/- 25% from the norm (ignoring the presence of any conservatory),

• This option can also be used if more than one type of multiple glazing is present, or

• If the orientation of the windows is massively different from typical arrangements (e.g. a house incorporating passive solar features where there is only a large amount of windows present on the south façade).

However a HI/DEA or Home Inspector will rarely be required to measure windows individually, in 99% of cases the standard window categories can be used.

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Some examples of when the window areas should be measured are:

An example of a low energy passive solar house where the typical areas and orientations of glazing assumed would be dramatically wrong. A penthouse flat may also have large window area and require the assessor to measure the windows. A ‘black house’ on the Isle of Lewis, Outer Hebrides, Scotland– no windows whatsoever! Therefore record as ‘0 m2’ (doors are not counted, only windows). This case may also arise when windows have been added or blocked up subsequent to the dwellings original construction, or change of use.

When faced with some of these extreme cases each of the windows and roof windows should be measured individually for the main dwelling and any extensions recording:

- area (including frame) - glazing type (as above)

Note

The above is commonly referred to as a ‘sun room’ – follow the conventions defined earlier in this manual to determine if it should be classed as an extension or a conservatory. The HI/DEA will then need to record the correct window area (if the windows, including the glazed roof, are greater than the ‘much more than average’ category the windows may need to be measured for the dwelling as a whole).

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Multiple glazing type: The surveyor must record whether any double-glazed or triple glazed window units are pre 2002, or during or post-2002 (in Scotland the age band is post-2003, in Northern Ireland it’s post-2006), the presence of secondary glazing can also be recorded (no age band is required; just tick ‘secondary’ on the survey form). Temporary glazing products, such as cling film should be disregarded. If more than one age band of window is present the surveyor should select the type according to the most prevalent in the dwelling. Only one glazing type can be recorded, if there is a mixture of triple, double or secondary glazing is present then the glazing type which makes up the majority should be recorded. Some secondary glazing can be removed in the summer. In these cases record secondary glazing if the panels exist and can be re-fitted in the winter. If the surveyor is unsure of the age band then ‘unknown’ can be selected. Common ways of distinguishing post-2002 are:

Via the presence of gas fill (normally argon) – look for drill holes.

Via a wide gap >12mm The presence of low-e glass which can be detected using a laser gauge.

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Label may indicate date or presence of low-e/K glass Triple Glazing Triple glazing should be selected when there are three glass panes within the glazing unit. If there is a mixture of triple and double glazing, the majority should be entered or the details of each window entered separately.

Triple glazing will have two aluminium spacer bars within the glazing unit.

Doors The area of doors is assumed by RdSAP software to be 1.85 m2. The number of external doors is calculation based upon the built form:

• Flat/maisonette with heated corridor: 0 • Flat/maisonette with unheated corridor or no corridor: 1 • House/bungalow, enclosed mid-terrace or enclosed end-terrace: 1 • House/bungalow, not enclosed type: 2

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Ventilation The HI/DEA is required to determine if the dwelling is reliant upon ‘natural’, ‘MEV’ (extract only) or ‘MVHR’ (both supply and extract, with heat recovery) ventilation and also record the number of open fireplaces which influences the amount of background heat loss. Remaining information is assumed based on age, number of habitable rooms, the built form and construction type etc. (further information can be sourced from Section S4 in SAP 2005). Natural ventilation The following ventilation strategies are classed as ‘natural’:

• Where no other purpose provided ventilation system is present (i.e. the occupant can only open and close windows)

• Properties with local extract fans (in kitchens and bathrooms etc.) and trickle vents located within window frames

• Passive stack ventilation (PSV) Further information is provided below, but full descriptions can be sourced for the freely available Energy Saving Trust publication ‘Energy efficient ventilation in dwellings’ (GPG268 / CE124) from www.energysavingtrust.org.uk Intermittent extract fans with background ventilators

A trickle vent built into a window (with cover removed)

An extractor fan – can be manually controlled, switch on with the lighting circuit, have time delay and sometimes humidity sensors.

Local extract fans are installed in ‘wet’ rooms and provide rapid extraction of moisture and other pollutants. They operate intermittently under either occupant or automatic control. The fans can be either mounted in a window, ceiling or external wall. When ceiling-mounted, the extract should be ducted to outside. Replacement dry air is provided via background ventilators (e.g. trickle ventilators) and air leakage. In addition, as these fans do not run continuously, the background ventilators should be sized to provide adequate continuous whole house ventilation. Providing a gap at the bottom of the internal doors will allow the free passage of air through the property.

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Passive stack ventilation

A passive stack vent:

A PSV system comprises vents located in ‘wet’ rooms, connected via near-vertical ducts to ridge or other roof terminals. Warm, moist air is drawn up the ducts by a combination of the stack effect and wind effect. Replacement dry air is drawn into the property via background ventilators (e.g. trickle ventilators) located in the habitable rooms, and by air leakage. Providing a gap at the bottom of the internal doors will allow the free passage of air through the property.

Air bricks may be present in naturally ventilation dwellings to provide a source of fresh air for combustion appliances.

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Mechanical Extract Ventilation (MEV) A mechanical extract ventilation (MEV) system continually extracts air from ‘wet’ rooms. It usually consists of a central ventilation unit positioned in a cupboard or loft space ducted throughout the dwelling to extract air from the wet rooms. (Other configurations do exist, including the use of continuously running individual room fans, although with the latter, care must be taken to minimise the effects of wind pressure on the flow.) An MEV system (pictured right):

The system is typically dual speed, providing low-speed continuous ‘trickle’ ventilation, and high-speed ‘boost’ flow. Replacement dry air is drawn into the property via background ventilators (e.g. trickle ventilators) located in the habitable rooms, and by air leakage. Providing a gap at the bottom of the internal doors will allow the free passage of air through the property. If a ‘Positive input ventilation’ system is encountered the assessor should record it as MEV. BRE Tr

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Whole House Mechanical Ventilation with Heat Recovery (MVHR) A whole house mechanical ventilation (MVHR) system usually combines supply and extract ventilation in one system. Systems considered here incorporate a heat exchanger. Typically, warm, moist air is extracted from ‘wet’ rooms via a system of ducting and is passed through a heat exchanger before being exhausted to outside. Fresh incoming air is preheated via the exchanger and ducted to the living room and other habitable rooms. An MVHR system (pictured right) – note the 4 vents on the top – every MVHR system has these. Washable filter is also shown:

These systems can be effective at meeting part of the heating load in energy efficient dwellings, and helping to adequately distribute the heat. The system is typically dual speed, providing low-speed continuous ‘trickle’ ventilation, and high-speed ‘boost’ extract flow. These systems can provide the ideal ventilation system, delivering the required ventilation rate almost independently of the weather conditions. However, the energy saving benefits are only realised for airtight properties (i.e. new-build dwelling or low-energy properties) when almost all ventilation air passes through the heat exchanger.

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Number of open fireplaces The count of open fireplaces is used to calculate ventilation heat losses due to their presence, this question does not relate to the heating system present. The definition of an open fireplace is one with either an open chimney or a flue duct of 200mm or wider in diameter. All fireplaces which meet this definition should be included in the count. The following are not counted as open fireplaces:

• Any open flue which is less than 200mm diameter • A permanently blocked fireplace, even if fitted with an air brick. • Any heating appliance with controlled flow of air supply. i.e. closing doors. • A flexible gas flue liner sealed into the chimney (because diameter is less

than 200mm) • A chimney fitted with a damper enabling the flue to be mechanically closed

when not in use.

A fireplace with an open fire, or fire in grate, would qualify as an open fireplace.

A fireplace with a heating appliance which incorporates a closing door is not included in the count of open fireplaces.

Permanently sealed chimney should not be counted as an open fireplace.

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Heating and hot water

Covered in this section: § Heating system classification § Fuel choice § Heating controls § Water heating

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Heating and hot water

• Most time consuming section! • RdSAP allows different main and secondary space heating systems to be

specified. • Boilers are the most troublesome to accurately identify as you need the fuel

type, age and features as a bare minimum. • Heating controls must also be recorded. • Only one type of water heating system can be selected.

Each of the above items must match a category on the RdSAP heating list.

Categorizing the heating system In some cases it may not be immediately clear which of two systems present should be classified as the main system and which as the secondary. In these cases the system which is cheapest to use should be taken as the primary, and if there is still doubt, i.e. if they are both equally cheap to use, select the system that heats the living room. The other system can still be input as a secondary system but it needs to be input as a room heater. A room heater system should be chosen so that its efficiency closely reflects (but does not exceed) that of the actual system (as defined by the heating tables in the full version of SAP). The chosen room heater should also use the same fuel/tariff as the actual system. If two types of secondary heater are present, that which heats the greater number of rooms should be specified as the secondary system (and the other secondary heaters disregarded). If that condition does not resolve the choice, the system which is the cheapest to use should be specified. The decision to include a secondary heating system should be based on the characteristics of the dwelling and the systems installed and not on the heating practices of the occupying household. To summarise: The main heating system The secondary heating system

• Heats a large proportion of the

dwelling • Is not usually based on individual

room heaters • Often provides hot water as well as

space heating • Is generally the cheapest to run

• Is always based on room heaters • Is based on the characteristics of the

dwelling, not the occupancy habits • Direct acting electric heaters are

assumed as the secondary heating system unless you specify the presence of fixed room heaters.

For situations where there is no fixed heating in a property, the option ‘no space heating system’ should be entered. The software will assume on-peak portable electric room heaters as the main system when this is selected. If a permanently fixed room heater is present it should be included as secondary heating regardless of whether “central heating” heats all rooms.

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If more than one secondary heater:

(a) select the device that heats greatest number of habitable rooms; (b) if that does not resolve it, select the device using the cheapest fuel; (c) if that does not resolve it, select the device with the lowest efficiency.

Electric focal point fires are included even if not wired by a fixed spur. Select "None" if no form of fixed secondary heating system is present. Note: If no heating system is present, as of SAP2005 v9.82 there is now an option to select ‘no heating system’ (Code 699). In these cases portable electric heater with no controls are assumed. Note: If a property being surveyed uses two boilers to provide the heating, which use the same fuel and have similar efficiency (based on their features such as flue type etc…), you should firstly select the boiler which heats the majority of the dwelling. If they heat equal proportions of the dwelling it would be best to model them as 1 boiler, but using the least efficient one of the two. BRE Tr

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Electricity tariffs

• ‘Single’, ‘Dual’ or ‘Unknown’ (dual 24-hour can also be selected, but only when undertaking EPC for Scotland)

• Generally easy to identify a dual rate meter – ‘Low’ & ‘high’ or by the presence of storage heating

• Special tariffs e.g. heat pump or white meter should simply be recorded as ‘dual’

• Pre-paid meters are not differentiated within the survey (but can be important for giving energy advice)

Fuel type Mains gas pretty easy to spot, but…

Oil tank Underground

LPG cylinder LPG Cylinder Bottled Gas

Be sure that you don’t miss the presence of LPG or oil which are especially common in rural situations. It is VERY important that the correct type of fuel is recorded as the impact on the SAP rating is enormous.

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Anthracite nuts or grains. Can be used in stoves and boilers and will be found in smoke control areas. It can be found in a number of sized “nuts” and “grains”. The “grains” are used in auto feed boilers.

House coal can be used in stoves and fires but won’t be used in smoke control areas.

Manufactured smokeless fuels e.g. Coalite Can be used in stoves/ fires and some boilers - will be used in smoke control areas. Smokeless fuel will be reformed in a variety of sizes. It will probably only be found in a smoke control zone because it is more expensive than coal.

Wood, wood-chip, pellets, logs or coppice Look for evidence of use of wood. Piles in the garden/shed/garage. This fuel could be in the form of wood-chip, reformed pellets, logs or coppice.

SAP Table 12b provides indicative list of which fuels are used with which appliances. If a heating appliance can only burn on fuel, then record that fuel (includes exempted appliances burning wood in smoke control areas). Otherwise:

• In a smoke control area: o Open fire, select ‘smokeless’ o Closed heater, select ‘anthracite’

• Not in a smoke control area:

o Open fire, select ‘dual fuel’ o Closed heater, select ‘wood logs’ if capable otherwise ‘anthracite’.

Is mains gas available? ‘Available’ means that a mains gas supply is available within the property (e.g. a mains gas meter or mains gas appliance is present). A closed-off gas pipe alone does not count.

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Boilers You should record the brand name, model and model number in addition to its generic type (and associated code). For example:

The preferred source of boiler efficiency is the government's Boiler Efficiency Database, which contains boiler efficiency figures intended for use in SAP. Note:

• You should attempt to enter gas, LPG or oil room heaters with a back boiler via the boiler efficiency database

• You cannot enter solid fuel boilers via the boiler efficiency database 1. The government’s boiler efficiency database Can be accessed via www.boilers.org.uk, with this database also being integrated directly by the RdSAP software:

• Incorrect boiler identification could make a very big difference to the accuracy of your rating (up to 10 SAP points) – so don’t guess or select a close approximation!

• Most other (old/obsolete) boilers have estimated values from SAP Table 4b. • Boiler ID may sometimes be located on the top of the boiler

Regular, wall mounted, non-condensing gas boiler, fan assisted flue, automatic ignition, post-98

Potteron

Profile

100e

101 Non-condensing post-98 regular gas boiler

1 Mains Gas

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BOILER DATABASE TIP Can’t find a particular boiler – try some of these.... Ideal boilers - Caradon Plumbing Ltd (also known as Caradon Ideal ltd) Potterton Myson Ltd has several names under which it originally traded before being taken over by Baxi Heating Ltd e.g. Potterton International Ltd, Potterton Myson Heating, Myson Combustion Products Ltd Bosch – can be found under Worcester Heat Systems Burco Dean Appliances Limited can be found under Maxol Centurion boilers can be found under Boulter Boilers Ltd Claudio boilers can be found under Vokera Ltd Wickes combi boilers can be found under Halstead Boilers Ltd Saunier Duval boilers can be found under Hepworth Heating Ltd Trisave boilers can be found under Crosslee plc Or use The blue book of boilers: Energy Efficiency Hotline on 0845 727 7200. 2. Generic boiler type For a boiler you must record the following information on the survey form:

• Fuel • Date of manufacture • Flue type • Non-condensing or condensing • Regular or combi • Automatic ignition or permanent pilot light • Floor, wall or back boiler

Above all you must match a generic boiler category on the RdSAP heating list.

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Identifying boilers Combi boiler

• More pipes entering the boiler (5 or

6 instead of 3) • The boiler firing when the hot water

is turned on • No hot water cylinder • A pressure gauge • Heating and hot water controls on

the front panel

Condensing boiler (either regular or combi) Must have both of the following features present:

Fanned flue – pluming will be visible in

cold weather

Plastic condensate pipe to main drain (usually white as above)

Boiler age?

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The date refers to the year of manufacture of the boiler. If this is uncertain the older category should be used.

• Styling clues • Pilot light not very common post-98. • Manufacturers label • Presence of Energy Efficiency Recommended logo (generally indicates post-

98) • Ask the occupant

Notes: Boilers 1998 or later If the ignition type is not known, a boiler with a fan-assisted flue may be assumed to have automatic ignition, and one with an open flue to have a permanent pilot light. A piezo electric switch will be required on any boiler which has a permanent pilot light in case it needs re-lighting. Heat emitters If both under floor and radiators are present, then enter radiators. Boiler missing or not working If boiler/heating system is present but not working (or condemned) it should still be entered as the main heating system. If boiler is not present – enter ‘no heating system’. Micro-CHP This type of heating system is not yet modelled in RdSAP – if a Micro-CHP system is installed it should be recorded as a condensing boiler. Addenda The DEA must ensure that the following addendum is selected in RdSAP software so the EPC produced will clearly state how the Micro-CHP unit has been modelled: 5. Dwelling has micro-CHP. “The dwelling has a micro-chip system. This is outside the scope of the assessment methodology and a condensing boiler was used for the assessment.”

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Flues and chimneys Applies to boilers and warm-air systems. For fires and room heaters use normal flue type indicated in their description (see Table 4a of SAP or heating system code list)

Balanced flue

Fan assisted flue

Fan assisted flue

Pre-fabricated open flue (either lining the chimney or on outside wall)

Ridge flue (A form of open flue)

Conventional brick-built chimney - combustion products rise through convection and are also drawn up by wind passing the top of the chimney, creating an up draught. These are built in to the original design of the house. - Class 1 Flue Pre-cast concrete flue - common in newer homes, these are built into the original walls - without increasing their thickness. - Class 2 Flue Prefabricated flue - usually a later addition, this is a twin-skinned flue (made from stainless steel) which is attached to the inside of a wall and led away either through the roof or through an outside wall. These are sometimes boarded over to imitate a chimney breast - Class 2 Flue if less than 152 mm Balanced flues are always found on an outside wall - giving the shortest and safest route to disperse the products of combustion. Note: The term ‘room-sealed’ means it is not an open flue. Open flues are like chimneys in many respects – they draw air from within the house (hence requiring an air brick in the room in which they are present) and have quite large diameters. They are not fanned. The terms ‘room-sealed’, ‘fan assisted’ and ‘balanced’ all imply that a flue type is not ‘open’.

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Combined Primary Storage Units (CPSU)

• Contains a >70litre

hot water store within the boiler casing which feeds both space heating and hot water

• The thermal store is heated directly

• Floor standing • Larger casing • Gas or electric

Gas CPSU (note flue, which can be balanced or open flue)

Electric CPSU (no flue)

Three criteria must be fulfilled for a boiler to qualify as a CPSU. These are as follows:

• The store and boiler must be in the same casing. • The store must have a capacity of at least 70 litres (if the store is less than

this it should be treated as a storage combi). • The space heating circuit feed must be taken directly from the store (while in

the case of a storage combi, the store does not feed the space heating circuit).

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Back boilers

• Can be either closed or open, solid or gas • Check for water pipes around the

appliance • There will be evidence of a heat

distribution system but no obvious signs of a standalone boiler

• Note the brand name, model and model number – it could be in the boiler efficiency database

• Where the back boiler provides hot water only – enter as secondary heating

• If the back boiler is fuelled by gas – select back boiler as the primary heating system type and record the gas fire in-front of the back boiler as the secondary heating system

• For oil and solid fuel back boilers – record these as the primary heating system as appropriate, but do not record the fireplace in-front of the unit as a secondary heating system (however if there is another secondary heating system elsewhere do record it)

There will be evidence of a heat distribution system but no obvious signs of a standalone boiler. If fuelled by gas, it may be possible to enter via the boiler efficiency database etc... (i.e. same procedure as with boilers) – solid fuel boilers must be entered according to their generic type. Record the brand name, model and ID. Good practice for recording a solid fuel heating system would be:

“Inset rectangular grate open fire with back boiler to rads” HETAS has lots of useful information and efficiencies of some appliance types. Note If modelling a room heater with a back boiler, you will also need to consider if you need to model the fireplace in front of the fire as a secondary heating system. The following rule applies: 1. If a boiler is selected and the fuel is gas (heating code 109 or 119), then the room

heater in front of the fire should be recorded separately as secondary heating. 2. If a boiler is selected and the fuel is not gas, then no form of secondary heating

needs to be recorded as secondary.

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3. If fire (any fuel) with boiler is selected (this means the boiler does DHW only, not

radiators), then the fireplace does not need to be recorded as secondary. The rules for selecting secondary heating systems still apply, so there is another form of secondary heating that heats a greater number of habitable rooms then that should be recorded instead.

Stand-alone boilers Solid fuel

• Run on anthracite nuts or grains only • Open flue or chimney • Supply heat and hot water (vented) • Manual (or batch) feed boilers require regular

refuelling approximately every 10hrs • Auto feed (or gravity) boilers include a hopper on

the top of the boiler – these can supply heat for up to 36hrs without refuelling or de-ashing

• Forced draught fan is sometimes used to boost heat output

These can provide full central heating for most dwellings and are available in a wide range of outputs and sizes. Batch fed units will provide domestic hot water and sufficient heat for a three to four bedroom house. Gravity fed boilers (which have a large hopper over the fire box) will operate for up to 36 hours at minimum output and for 10 hours on full burn rate without refuelling or de-ashing. All of them burn small anthracite nuts or grains which are feed into the fire as necessary. Combustion is assisted by a built-in thermostatically controlled fan, which helps adjust output to demand. Gravity-fed units have a high turn down (around 10:1), which means that they can kindle at low combustion rates, compared with other solid fuel appliances. There is still some background heat given off when the boiler is turned down to minimum, helping to prevent condensation within the dwelling.

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Wood chip and pellet Modelled using the same systems as solid fuel boiler, but record the fuel type as wood chips or pellets.

• Run on wood chip or pellets only • Open flue or chimney • Supply heat and hot water (vented) • Always auto-feed via a hopper • Forced draught fan is sometimes used to boost

heat output Please read EST’s Energy Efficiency Best Practice in Housing guide: Domestic heating by solid fuel: boiler systems (CE47) available from www.energysavingtrust.org.uk

Electric direct acting boilers

• Compact size • No flue or fuel storage required • Only two pipes – feed pipe is located

on the top, return on the bottom • Used in similar arrangement as a

normal boiler

e.g. Heatrae Sadia Electroheat Range, Trianco Aztec Electric Boilers or Redring dualheat.

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Electric storage boilers

• Wet and dry core varieties • Provide heating and hot water • Economy 7 tariff (if run on on-peak then it’s a

direct acting electric boiler) • Controlled by room thermostat and TRVs only • GEC ‘nightstor’ is a dry core off-peak boiler • Extremely rare!

During all off-peak periods, the boiler automatically engages recharge mode. Some or all of the upper heaters (according to boiler specification) are turned on as is the lower heater if present. Additionally, the primary pump is operated from time to time during recharge; this cycles water through the boiler to ensure that it is all thoroughly recharged. The heaters turn off automatically when the whole boiler reaches the full recharge temperature. If further heat is used during the off-peak period, the heaters will come on again as necessary to maintain full charge. On some models, the recharge temperature is near boiling point, and will be higher than the boost temperature.

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Range cookers Range cookers are flued cooking appliances predominantly constructed of cast iron designed to provide some heat from their case into the space in which they are located.

• Can be run on gas, oil or solid fuels • Normally open flued (sometimes also

includes a balanced flue if an internal boiler is present)

• Ranges, such as AGAs, which supply hot water only are sometimes interconnected into a gravity fed hot water supply to supplement a boiler or other heat source

• Twin burner models contain an integral boiler fuelled by mains gas, LPG or oil which supply central heating to the dwelling - these should be modelled according to the same procedure as a boiler (i.e. preferably via the boiler efficiency database)

• Single burner models should be entered as a generic system, with the hot water being supplied from an on-peak electric immersion

Do not include in RdSAP calculations if the range only serves as a cooker!

Range cooker with boiler for space heating This type provides an independent water heating function for space heating in addition to the cooking function. There are two design variations:

• Twin burner range cooker/boiler – an appliance with two independently controlled burners, one for the cooking function, one for the water heating function for space heating

For the twin burner type, the efficiency can be can be from the boiler efficiency database, manufacturer's declaration or the generic efficiency if it cannot be found

• Single burner range cooker/boiler – an appliance with a single burner that

provides a cooking function and a water heating function for space heating

For the single burner type, a generic type and efficiency should be used. Hot water supply is sometimes mated with a special ‘twin coil’ hot water cylinder to make use of the hot water feed – the twin coil cylinder will include an immersion

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heater which is used when the range is not running – for single burner ranges (without an integral space heating boiler), the hot water should be recorded as an electric immersion heater. Note: An AGA does not supply central heating output, but a Rayburn can – for example their heatranger models.

Addenda The DEA must ensure that the following addendum is selected in RdSAP software so the EPC produced will clearly state how why a dwelling specified with a closed room heater for water heating as opposed to a range cooker: 2. Closed room heater specified for water heating instead of a range cooker. “The water heating in this property is from a range cooker. A closed room heater using the same fuel, which gives similar ratings, was used for the assessment.

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Warm air Gas & oil

• Gas/oil is burned to heat up hot water in a

heat exchanger • Air is drawn over this by a fan and ducted into

each room (ducted or stub-ducted) • Usually includes a built in hot water circulator

which feeds an external cylinder • You must record:

o Age o Non-condensing or condensing o Presence of any flue heat

recovery

Electric

• Such as Dimplex “electricaire” • Similar principle as gas or oil warm air,

except the central core is heated using off-peak electricity overnight

• Control panel contains a charge input (similar to storage heaters), a fan setting (normal or boost)

• Sometimes additional room thermostat is fitted to provide additional control

• Hot water will be supplied by a separate system

• Must be supplied by a dual tariff meter, if on a single meter then record as on-peak electric panel heaters.

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Storage heaters Storage heaters are usually more economical than direct acting electric heaters – a high density thermal block containing electric elements is charged overnight using cheap off-peak electricity. Charge and output controls in addition to a flap or damper moderate the amount of heat given out. Important Electric storage heaters can only be recorded as a main heating system. Storage heaters must be supplied by a dual tariff meter, if storage heaters are present but on a single meter then record as on-peak electric panel heaters and include Addendum 6. If electric storage heaters or off-peak electric underfloor heating is the main system, the assessor must specify a secondary system (see Appendix A of SAP); if no secondary heater has been identified the secondary system is portable electric heaters (code 693).

Old large volume

• Bulky, 9 to 12” deep • Normally free standing

Modern slimline

• 6” or less deep • Wall mounted, but will have legs/feet

Fan assisted storage heaters

• Blows air over storage heater – more responsive & improved distribution of heat

Integrated storage/direct acting heaters are a further option – their appearance is identical, but they incorporate a direct acting on-peak electric heating element to

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provide boost heating when the thermal block has run out of heat or the occupant wishes to have a quick boost of heat. These types of heater can remove the need for specifying a separate on-peak heater in the vicinity. Addenda The DEA must ensure that the following addendum is selected in RdSAP software so the EPC produced will clearly state how a storage heater or dual immersion has been modelled if run on a single tariff electric meter: 6. Storage heater or dual immersion and single meter. “A dual tariff appliance is present; changing the electricity tariff to an off-peak supply is likely to reduce fuel costs and improve the rating.”

Electric underfloor or ceiling heating

• Often used in extensions and living rooms (because

of its aesthetic & space saving features) • Unusual for it to be employed to heat the whole

dwelling, the main heating will normally be storage heaters

• Record control type • Integrated storage/direct acting underfloor heating

will have an off-peak and on-peak connection. • Older systems will have a numbered dial in the

lounge (which doesn’t display temperature) • If secondary system record as a direct acting electric

panel heater

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Heat pumps

• There are a variety of heat pump

systems, the most common being ground source or air source

• Ground source heat pumps use a long loop of pipe buried in the ground to extract low temperature heat

• The heat extracted is then brought up to the demand temperature using electricity before being circulated around the distribution system, normally underfloor, but sometimes warm air

• Some heat pumps also require supplementary on-peak direct electric heating (record as ‘with auxiliary heater’)

• Air source heat pumps take heat from the external air

• Any fixed direct acting on-peak heaters should also be recorded as secondary heating on the survey form

A heat pump is a device which takes heat energy from a low temperature source and upgrades it to a higher temperature at which it can be usefully employed for heating. There are a number of heat pump techniques by which this can be achieved. The ratio of heat energy released to the energy consumed can be significantly greater than one. Heat pump systems operate most efficiently when the source temperature is as high as possible and the heat distribution temperature is as low as possible. The figures used in the SAP calculation apply to electrically driven, vapour compression heat pumps. Heat pump systems are categorised by the low temperature heat source used (e.g. air, water or ground) and the seasonal performance factors given in SAP2005 Table 4a are assumed to apply for all systems using that source. This is a simplified approach especially for ground source heat pumps where energy may be collected from the ground in a variety of ways, e.g. using surface water from lakes or ponds, using ground water from wells, using fluid (either refrigerant or a water/antifreeze mixture) circulated in closed pipe loops buried horizontally in shallow trenches or vertically in boreholes.

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Community heating Any heating (or hot water) system that serves more than one self-contained dwelling must be entered as ‘community’ heating.

• For purposes of RdSAP community heating

systems are defined according to the fuel burnt, source of fuel and whether or not power is also generated

o If the fuel type cannot be determined use ‘mains gas’

There are two options:

• Heat produced by boilers only, OR • Combined heat and power (CHP) units

For community heating schemes, the DEA only needs to record the fuel used to run the centralised community heating boilers, from the current options:

1 Gas. 4 Oil. 12 Manufactured smokeless fuel. 15 Anthracite. 42 Waste combustion. 43 Biomass. 44 Biogas.

It is recommended that the DEA contacts the supply company to identify the fuel type as this can be difficult to determine through the survey. If the fuel type cannot be determined, mains gas should be assumed. 'Flat rate charging' means that households pay for the heat according to a fixed monthly or annual amount, not depending on the amount of heat actually used. If the charges vary within a scheme for other reasons, for example according to dwelling size, it is still classified as flat rate. The last entry refers to a system in which the charges are substantially related to the amount of heat used. Addenda The DEA must ensure that the following addendum is selected in RdSAP software so the EPC produced will clearly state how a dwelling heated by an individual heating system, but with water heating from a community heating system, has been modelled: 3. Space heating from individual system and water heating from community system. “The water heating from this property is supplied from a community system. A multipoint gas heater, which gives similar ratings, was used for the assessment.”

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Shared or Group heating schemes All of the following are now considered ‘community’ heating:

• Where a more than one separate dwelling, and some communal areas, share the use of one boiler.

• Where a separate dwellings shares a boiler with any non-domestic space (e.g. shops or offices).

Common in old peoples homes and sheltered housing. For any number of separate dwellings sharing the same heating system, a separate EPC will be required for each self-contained dwelling for a single household.

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Room heaters Gas, solid fuel, oil or electric room heaters may be recorded: Gas room heaters Are primarily categorised according to the flue type Open flue

Gas fire, open flue, pre-1980 (open fronted) Code: 601 or 602 if it incorporates a back boiler (doesn’t feed radiators just provides hot water)

Gas fire, open flue, post-1980 (open fronted) sitting proud of and sealed to the fireplace opening (i.e. self contained unit) Code: 603 or 604 if it incorporates a back boiler (doesn’t feed radiators just provides hot water)

Gas flush fitting live fuel effect fire (open fronted), sealed to fireplace opening with open or balanced flue (as shown above). Code: 605 or 606 if it incorporates a back boiler (doesn’t feed radiators just provides hot water) For a fanned flued model: Code: 607

Balanced flue Wall mounted gas heater or open fronted heaters with balanced flues are common

Code: 609

Modern gas fire room heaters often have balanced flues and closed fronts to increase efficiency.

Code: 610

Condensing Condensing room heaters will have a condensate pipe and fanned flue (all fanned flues are balanced). Code: 611

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Chimney

Decorative fuel effect gas fire, open to chimney Code: 612

Solid fuel room heaters Are also categorised according to flue type: Chimney Open flue

Decorative open fire in grate Code = 631

Open fire with back boiler (no rads) Code = 634

Stove or closed room heater without a back boiler Code = 633

Closed room heater with back boiler (no rads) Code = 634

Remember: If a heating appliance can only burn on fuel, then record that fuel (includes exempted appliances burning wood in smoke control areas). Otherwise:

• In a smoke control area: o Open fire, select ‘smokeless’ o Closed heater, select ‘anthracite’

• Not in a smoke control area:

o Open fire, select ‘dual fuel’ o Closed heater, select ‘wood logs’ if capable otherwise ‘anthracite’.

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Direct acting electric room heaters Two categories may be selected: Panel, convector or radiant heaters Code = 691

Portable heaters Code = 693

Such as: Wall mounted radiant heaters:

Wall mounted panel heater:

Electric fires:

Electric kick space heaters:

Electric fan heaters:

Such as:

Portable fan heaters or electric radiators are only recorded if they are the only available form of heating, if there is another form for secondary heating this should be recorded first. If there is a primary heat system present and no other form of secondary heating then portable electric heaters should not be recorded and ‘none’ should be selected for the secondary heating system. This is because the heaters are not permanent the occupants may take them with them upon moving. Also by selecting ‘none’ RdSAP will automatically assign electric heating to provide secondary heating.

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Heating controls For boilers, warm air systems, heat pumps, community heating schemes and room heaters the control systems are formed from a combination of:

• Room thermostats • Programmers • Thermostatic Radiator Valves (TRVs) • Bypasses • Boiler energy managers • Zone controls

Selection of main heating control type will vary depending upon heating system, for example a warm air system will not have TRVs. Storage heaters differ from these standard control types, they have:

• Manual charge control • automatic charge control • CELECT-type control

Each type of control has a 'temperature adjustment' figure, in degrees centigrade, which is used to modify the living area mean internal temperature according to the control’s effectiveness. A poor control will cause the dwelling temperature to be uncontrolled to a greater extent, and hence the mean internal temperature will be higher.

Room thermostats

Room thermostat A sensing device to measure the air temperature within the building and switch on and off the space heating. A single target temperature may be set by the user.

• Normally mounted on a wall in the lounge or hall way.

• Stops the boiler and heating pump when the desired temperature is reached.

• Can be wired, battery powered or wireless.

Programmable room thermostat A combined time switch and room thermostat that allows the user to set different target temperatures for space heating, usually in a daily or weekly cycle.

• Provides both the functions of a programmer and room thermostat

• Should be recorded individually • May or may not include delayed start feature

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Thermostatic radiator valves (TRV) A radiator valve with an air temperature sensor, used to control the heat output from the radiator by adjusting the water flow.

• Are fitted on radiators and

have a range of temperature settings

• TRVs allow the temperature to be controlled in different rooms

• Normally used in conjunction with a room thermostat, control system or a boiler energy manager

Programmers and zone control Digital programmers, mini-programmers and time switches are just counted as ‘programmers’ – zone control looks similar – just don’t forget to check!

Digital programmer

• Two switches operated by a clock to control the ‘on’ periods for space heating and hot water

• Normally 7 day timing for both space heating and hot water

Time switch (or mini- programmer)

• Simple to use • Allows space heating and hot water to

be on at the same time, or hot water alone, but not heating alone

Zone control

• Allows separate programming and control of different zones in addition to water heating (e.g. 3 channel, zone 1, zone 2 and hot water)

• Separate room thermostats will be present in each zone

• If two (or more) thermostats and

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programmers are present, this also qualifies as ‘zone control’ (will serve the same function as the integrated unit pictured)

Boiler bypass Most boiler systems require some sort of bypass to ensure minimum boiler flow rates, and to protect the heating pump from dead-head conditions.

A fixed bypass:

• The presence of a radiator, or sometimes a towel rail, without a TRV

An automatic bypass

• Hand valve located between the flow and return circuit

• Looks very similar to a TRV

Boiler energy manager

A boiler energy manager monitors return and flow temperatures and reduces the boiler temperature accordingly. Current Boiler Energy Managers include:

• DCD heating controller • Dataterm Intelligent Heating

Controller • Eco-Burn • Honeywell AQ6000 • Danfoss BEM 5000

Incorporates a number of functions into a single boiler control unit, features may include: Delayed start - Reduces energy use by delaying the boiler start time when the weather is mild. Optimum start - Adjusts the heating time to give the required dwelling comfort temperature at a chosen time.

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Night setback - Allows a low temperature to be maintained at night. Provides improved comfort and reduced dwelling warm-up time in cold weather. A programmable room thermostat can provide this facility. Self-adaptive function - reduces appliance 'on' time by learning from previous temperature characteristics. Anti-cycling control - Delays boiler firing to reduce cycling frequency but is unlikely to provide significant energy savings. In some circumstances their use may reduce energy consumption, but usually at the expense of performance or comfort. Standalone units (those not supplied as part of the boiler) are generally not recommended as they provide little or no improvement over the minimum level of comfort. A boiler energy manager may also include weather or load compensation.

Weather or load compensation Not presently modelled in RdSAP, but here for information:

This is an internal or external thermostat that tells the boiler to adjust its temperature for space heating according to the internal (load compensation) or external (weather compensation) air temperature. Load and weather compensators cannot both be applied to a heating system - they are mutually exclusive. Can be specified for boiler systems or heat pumps only.

TIP A “Honeywell Frost Start” is disregarded as a part of the energy survey – this type of device is usually installed on to a boiler which is located outside of the heated envelope of the building (for example in a garage) the device will turn on the boiler for a short period if frosty conditions occur so that the water in the pipes does not freeze and damage the boiler or the distribution system. Essentially it is a safety device.

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Storage heater controls

There are two types of control that can be recorded on the survey form. Manual charge control The user adjusts the charging of the storage heater manually. Automatic charge controls Storage heaters which are wired to a thermostat which detects the internal temperature and adjusts the charging of the storage heater accordingly. A third type of control of CELECT control (where a central programmer is used to individually control each unit) – if this is present it should be recorded as ‘automatic charge control’.

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Water heating

• Normally from the main heating system or dual immersion • Select the system which delivers the bulk of hot water during the year. • If there is no water heating, select the ‘no water heating system’ option on the

field sheet. • Any back-up electric immersion heaters should be disregarded • Where water heating is from a back boiler or room heater with boiler, and the

boiler provides water heating only, the appropriate fire or room heater without boiler is identified in the data collection process, and the water heating is identified as from main system or from secondary system.

• Record description on survey form as well as code If no system is recorded the RdSAP software will undertake the calculation based on an electric immersion system.

Hot water cylinders If present, you must record:

Approximate size: • No access • Normal (90-130 litres) - typical for a boiler • Medium (131-170 litres) - for larger

households • Large (>170 litre) - typical for dual

immersions Insulation type: • None • Spray foam • Jacket

Insulation depth, in millimetres: • A ‘poor’ quality or badly fitting jacket should

be recorded as having 50mm or less depth. • Presence of a cylinder stat • If not visible the cylinder stat can sometimes

be located beneath the jacket A separate thermal store should be recorded on the survey form as a hot water cylinder.

Where it is not possible to record the depth of the hot water insulation ‘no access’ should be selected on the survey form. Mains pressure (or ‘unvented’) hot water systems are not treated in RdSAP any differently from conventional boiler-to-cylinder ‘vented’ hot water systems. DEAs must therefore record the cylinder (size, insulation etc.) in exactly the same way as a conventional cylinder system. For DEAs information, one currently popular make of

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mains pressure hot water system is the ‘Megaflo’. If you come across it in the field record it as per above. A thermostat on an immersion heater is not considered to be a cylinder thermostat if the immersion operates as a back-up system and is not the primary hot water source (essentially the immersion thermostat is an emergency cut off). A separate cylinder thermostat is required in all cases for ‘Yes’ to be marked on the survey form.

Dual immersion

A dual immersion heater system is either one with two separate immersion heaters (one at the bottom of the cylinder and one close to the top) or a 'two-in-one' heater with two elements (one long and one short). The two-in-one type can be distinguished by two supply wires entering a single appliance. There is one other type of two-in-one immersion heater encountered occasionally in older properties. These are normally attached to a switch with a ‘sink/bath’ option. This is still classified as a single immersion heater since the electricity used is the same for both elements for these particular systems.

Addenda The DEA must ensure that the following addendum is selected in RdSAP software so the EPC produced will clearly state how a storage heater or dual immersion has been modelled if run on a single tariff electric meter: 6. Storage heater or dual immersion and single meter. “A dual tariff appliance is present; changing the electricity tariff to an off-peak supply is likely to reduce fuel costs and improve the rating.”

Other hot water only systems If not supplied from the main heating system or immersion heating the following options are also available:

Independent electric water heating system

• Electric showers • Point of use instantaneous water heaters – wall mounted

or under worktop appliance with open swivel outlet or connection to one tap only. Mounted near sink. No flue and only electric fuel supply. ‘Single-point’ heaters, which are located at the point of use and serve only one outlet, do not have distribution losses

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Single-point gas water heater A gas single point water heater provides water to a sink immediately below the appliance itself. Multi-point gas water heater A gas multi-point water heater provides hot water to more than one outlet; usually a sink in the kitchen and both basin and bath in the bathroom. Hot water provided from community system In these cases a gas multi-point water heater should be selected and the recommendation for a new gas boiler should be suppressed. Range cooker supplying domestic how water only If a range cooker supplies hot water then enter the secondary heating as a ‘Closed room heater with back boiler (no rads)’ and record the same fuel as the range cooker. In this case any other form of secondary heating cannot be included in the assessment – in that case record the presence of additional secondary heating in site notes with comment that it could not be included.

Addenda The DEA must ensure that the following addendum is selected in RdSAP software so the EPC produced will clearly state how a dwelling heated by an individual heating system, but with water heating from a community heating system, has been modelled: 3. Space heating from individual system and water heating from community system. “The water heating from this property is supplied from a community system. A multipoint gas heater, which gives similar ratings, was used for the assessment.” Addenda The DEA must ensure that the following addendum is selected in RdSAP software so the EPC produced will clearly state how why a dwelling specified with a closed room heater for water heating as opposed to a range cooker: 2. Closed room heater specified for water heating instead of a range cooker. “The water heating in this property is from a range cooker. A closed room heater using the same fuel, which gives similar ratings, was used for the assessment.

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© Building Research Establishment Ltd 2009 - 113 -

Renewables, lighting and miscellaneous

Covered in this section: § Renewable technologies § Lighting

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Renewable Technologies

Solar hot water Two main types – ‘Evacuated tube’ or ‘Flat plate’ collectors.

• Simply ‘Yes’ or ’No’ question to indicate presence • A fixed area of 3m2 is assumed • Don’t confuse with Photo Voltaics (PV) • A storage tank is necessary to contain the hot water generated – this can either be a

specially adapted hot water cylinder or an additional linked in cylinder to supplement the main heating system.

Evacuated tube

Evacuated tube collectors use metal plate collectors running through vacuum tubes. The vacuum acts as insulation preventing convective heat loss.

Flat plate on roof

Flat plate collectors use a metal absorber plate, often coated with low emissivity black paint. They are usually single glazed but can have a secondary glazed layer (sometimes of plastic) allowing higher temperatures to be achieved.

The area taken up by a solar water collector will vary according its design and the hot water needs of the house concerned. Typically it could be anywhere between 2 m2 and 7 m2. The usual arrangement in the UK with the collector above the tank requires a pump to circulate the water.

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Photovoltaics (PV)

• Generate electricity from light • Different module types are not differentiated • Can be a ‘bolt on’ after market system or ‘building integrated’ • If present record PV area as a proportion of total roof area, even if it is not mounted on

the roof. • For flats the PV may be incorporated into the block and may be shared between

different units or used to supply electricity to lighting in the corridors. In all cases split the amount of PV equally between the flats.

PV integrated into side of building

PV roof tiles

PV ‘bolted’ onto roof

PV external to building (could not be integrated onto roof due to either inadequate siting or planning permission)

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Wind turbine

• Generates electricity from wind energy • Can either be free standing or building mounted • If present record ‘yes’ on field sheet

Free standing

Free standing turbines have their own mast and can be located several metres away from the property.

Building mounted

Building mounted turbines are secured to the structure of the property.

Linked to the ‘Terrain type’ question – see the Dwelling details section.

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Low-energy lighting Record the proportion of fixed outlets which have low energy lamps. To be fixed the lighting outlet cannot be removable (so desk lamps etc. are excluded from the proportion). Decorative or indirect lighting, provided it is fixed, is also counted when recording the proportion of fixed outlets which have low energy lamps, such as the examples below:

A fixed outlet may contain more than one lamp, for example a light fitting containing three Edison screw tungsten spotlights is counted as one fixed outlet (non-low energy). Further examples below: An example of one fixed outlet with 3 halogen lamps (therefore does not count as low-energy)

An example of one fixed outlet fitted with 2 low-energy tubes

Recessed lights (such as in kitchens) divide the bulb count by 2 and round up to get the number of outlets (usually on a single circuit).

Note: when dealing with down lighters or multiple individual spot lights. Where there are 4 or more down lighters or ceiling lights on the same circuit, divide the bulb count by two and round up. When deciding whether a fixed outlet counts as ‘low energy’ you should include both dedicated low energy lamps (pin based or strip based) and compact fluorescent lamps (which may be removed by the occupant, but still include these within the count). If a mixture of low energy lamps and traditional tungsten or halogen lamps (tungsten and halogen are not counted as low-energy) are present within the fixed outlet then the majority should be taken.

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Dedicated ‘pin-based’ low energy lamp fitting

‘Double-d’ type fluorescent low energy lighting (left hand side) and bayonet tungsten (right hand side). Switching on the light can indicate the presences of a fluorescent tube (quality of light and speed of start-up etc.)

‘Compact Fluorescent Lights’ CFLs

‘Compact Fluorescent Lights’ CFLs (spotlights)

A fixed outlet with 2 recessed CFL lamps

Recessed LED lamps (can be differentiated via quality of light and also the fact that individual diodes can be seen)

Important Low voltage lighting does not qualify as ‘low-energy lighting’ A lamp fitting with more than one bulb counts as one outlet, the same is true for a down lighter, but any switching circuit is disregarded (just look at the lamp fitting). If there is a mixture of low-energy lamps and traditional tungsten for example then use the 50:50 rule.

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Advice and Recommendations

Covered in this section: § How does RdSAP generate advice § When to suppress advice § Other issues

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How RdSAP generates advice All improvement suggestions in the RdSAP energy performance certificate are automatically created in the software. Default logic will recommend increasing sub-standard measures reported by you in the report to target levels. Perhaps more loft insulation is required, for example. The certificate will present financial savings and the improved SAP ratings from the suggested improvements. The fuel prices used to generate the savings and running costs on Energy Performance Certificates is updated twice a year at the end of June and December. The Home Inspector or DEA can suppress suggestions if unsuitable for a particular property, but enter the reason in the software. Recommendations should be removed only if there is evidence, visual or documentary, showing that a specific recommendation is not appropriate. The EPC contains caveats to the effect that further guidance on specific recommendations should be sought from an appropriate professional organisation, for example heating engineers, building control officers, product manufacturers, trade associations, energy efficiency adviser, etc.. A listed building or a property in a conservation area is not sufficient grounds in its own right to suppress a recommendation. If a recommendation is removed this must be recorded in site notes and the software. The software will not suggest anything that does not match the building construction description. This process gives you the opportunity to help the UK to save energy, money and our planet.

Providing Advice DEAs are encouraged to point clients towards sources of impartial energy efficiency advice such as trade bodies and reputable charities, such as the Energy Saving Trust. The DEA should not sell or promote specific solutions. Energy saving recommended

The Energy Saving Trust manages a labelling scheme for products of proven energy efficiency. The scheme currently covers appliances (washing machines, fridges, freezers, dishwashers and tumble dryers), light bulbs and fittings, gas and oil boilers, heating controls, loft insulation, cavity wall insulation, external wall and dry linings, high performance hot water cylinders and windows. These products carry the ‘energy saving recommended’ label. Currently endorsed products can be found at www.est.org.uk/recommended/

Free, local independent energy efficiency advice can also be provided by phoning the Energy Saving Trust on 0800 512 012. This telephone number is also provided on the energy performance certificate.

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Improvement Measures The improvement measures are grouped into three main sections: 1. Lower cost These are improvements that really should be done. - they cost less than £500 2. Higher cost These will require more investment and effort but are well worthwhile. - they cost more than £500 3. Further improvements These will help the environment further and should be seriously considered. - more expensive, really the ‘icing on the cake’ after all basic measures have been undertaken. The RdSAP software tests for the relevance of improvement measures, and applies them where relevant, in the order provided on the following pages. Several heating measures apply when mains gas is not available. When mains gas is available they are substituted by a fuel switch recommendation. In addition to the criteria of flagging a recommendation as suitable, the SAP rating must also be improved by at least 0.95 points for the measure to be deemed worthwhile and displayed. For low energy lighting this improvement is reduced to 0.45 points.

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Lower Cost Measures Hot water cylinder insulation

Recommended for…

– Cylinder present with less than 25mm of spray foam or less than 100mm jacket

Improve to… – 160mm jacket and 50mm thick of pre-formed primary

pipework insulation. – Or add 80mm jacket if spray foam already present

When not to recommend… – No reason

Priority measure! Will save twice its cost within a year.

Typically Annual saving approx £100 Installed cost from £10 Payback around 6 months Loft insulation

Recommended for…

– Pitched roofs only with less than 150mm of insulation – Main property and any extensions

Improve to… – 250mm – Recommendation will be provided separately for the

main dwelling and any extensions When not to recommend…

– No access (software will recognise this) – Condensation in roof space – Blocked ventilation at eaves – Bats and their roosts

• Pitched roofs are usually insulated with 250mm to 300mm of mineral wood between the

joists • Can be done between the rafters also using either rigid insulation boards or spray foam

(if unventilated roof space) Typical Annual saving up to £220 Installed cost around £230 Payback around 1 year Installed by experienced DIYers or a professional

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Cavity wall insulation Recommended for:

– Unfilled cavity walls (either ‘as built’ or ‘unknown’) with a U-value >0.6 W/mK

– Main property, any extensions and alternative walls Improve to:

– Filled – Recommendation will be provided separately for the

main dwelling and any extensions When not to recommend:

– Signs of water penetration (as opposed to condensation or rising damp), poor pointing, exposed site, blocked or narrow cavities.

www.ciga.co.uk The Cavity Insulation Guarantee Agency provides independent 25 year guarantees for Cavity Wall Insulation fitted by registered installers. Typically Annual saving £130-160 Installed cost around £260 Payback less than 2 years One of the most effective energy savings measure that most people can carry out on their homes. Draught proofing Recommended for…

– Single glazed windows Improve to…

– Draught proof all single glazed windows. Draught proof-area includes all windows (but not doors)

When not to recommend… – Condensation problems on walls or windows – Take caution when dealing with historic buildings – Permanently sealed units.

www.dpaa-association.org.uk The draught proofing advisory association.

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Quality draught-stripping on all windows and external doors reduces heating costs, particularly on those larger buildings. Typically Annual saving £20 Installed cost around £75 Payback less than 4 years Financial savings are hard to quantify, main benefits are improvement in comfort and reduction of draughts. Low energy lights

Recommended for… – All cases where less than 100% low energy lighting is present

Improve to… – 100% for all fixed outlets

When not to recommend… – No reason, even if existing light shade or fitting might not look

attractive… www.est.org.uk/recommended/ Energy Saving Recommended Typically Annual saving £20 Installed cost around £15 (4 lamps) Payback less than 1 year Financial savings continue for the life of the low-energy lamp. CFLs last 12x longer than conventional tungsten lamps.

More information and tips in… ‘Low energy lighting – a summary guide’ (GIL 20)

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Low energy appliances Not part of RdSAP recommendations (because these are non-permanent items)

– However, advice on upgrading to A-rated or Energy Saving Recommended appliances should ideally be given if the occupant is present during the survey.

– If appliances are to be replaced upon moving house energy-efficient models usually cost no more than equivalent less-efficient models to purchase.

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Hot water cylinder thermostat Recommended for…

– When a hot water cylinder is present and accessible and a thermostat has not been recorded on the survey form

Improve to… – Cylinder stat (note that a cylinder thermostat is assumed

for all electric immersion heating). When not to recommend…

– Accessibility? – No real reasons why you would suppress this measure

– Savings of at least £50 per year – Allows boiler to switch off when no heat is required. – Actual savings difficult to estimate due to occupant habits and

hot water usage – Whilst not generated as a recommendation by RdSAP software

if the primary pipe work is not insulated it would be good practice to do so whilst undertaking the work.

Heating controls for wet central heating systems

Recommended for… – All systems which have less then a room stat, programmer

and TRVs Improve to…

– Rooms stat, programmer and TRVs – Or ‘zone control’ if underfloor heating – Savings generated by the software will represent the

enhancement made to the existing control system. When not to recommend…

– Accessibility? – No real reasons why you would suppress this measure

See ‘CHeSS’ (CE51) for further guidance: Typically Annual saving £70 to £90 Installed cost around £250? Payback less than 1 year

£250 highlighted because a heating controls upgrade should really be in the lower cost measures category as it doesn’t cost £500. Heating controls can be upgraded at any time, are most cost effective and economical when carrying out work on an existing heating system.

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Also recommended for… – Heat pumps – Warm air systems

Improve to… – Similar package as per wet central heating systems

When not to recommend… – Accessibility? – No real reasons why you would suppress this measure

Note: The current performance of a ‘Programmer with bypass and TRVs’ should be reported as ‘Poor’ because without a roomstat a boiler interlock cannot be provided. ‘Room stat, programmer and TRVs’ should be reported as ‘Average’. Higher Cost Measures Boiler upgrade (Same fuel)

Recommended for…

– All non-condensing boilers (regular, combination or CPSU) – Range cookers

Improve to… – Band A condensing boiler of equivalent type and fuel – New separate boiler recommended for range cookers

When not to recommend… – Flue and boiler location problems – No reason why you would suppress this measure even if

the boiler is relatively new and in good working order.

See ‘CHeSS’ (CE51) for further guidance: Typically Annual saving £130 to £160 Installed cost around £2500*

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* High cost measure – but marginal cost of specifying an energy efficient model can be less than £50 when replacing a boiler.

Biomass boiler or wood pellet stove

Recommended for:

– Independent solid fuel boilers where mains gas is not available

Improve to:

– Manual feed biomass boiler or wood pellet stove with immersion heater to provide hot water in the summer

When not to recommend:

– No real reasons to suppress, but supply of wood logs and location of property (urban or rural) is important

– Existing boiler appears new and is in good working order

Heating controls of wet central heating systems

– Fuel choice very important – Fuel switch to wood is possible, but at present RdSAP only recommends a ‘fuel

switch’ to mains gas where it is available. – Flue and boiler location will be assessed by the installer – see CLG ‘condensing boiler assessment procedure’

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New or replacement storage heaters

Recommended for: – Any dwelling where mains gas is not available – Dwellings with old storage heaters, electric room

heaters or electric ceiling heating Improve to:

– Fan-assisted storage heaters and secondary electric panel heaters (if no existing secondary)

– Existing hot water system is replaced with a dual-immersion system


– No real reasons to suppress, but more environmentally friendly options are available

New or replacement warm air unit

Recommended for:

– Dwellings with warm air units older than 1998 Improve to:

– New non-condensing warm air unit, same fuel as original, on-off control with a fan assisted flue


– No real reasons to suppress, but where possible swapping to a wet central heating system with a condensing boiler would make more sense (further measure)

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Further Measures

– Can dramatically reduce the environmental impact of a dwelling, consisting of: – Higher cost traditional fabric measures – Fuel switching

– E.g. swap from storage heaters to gas condensing boiler if mains gas is available

– The addition of renewable technologies Renewable technologies should generally only be considered after carrying out all basic

energy efficiency improvements. Solar hot water heating

Recommended for…

– Any dwelling with a separate hot water cylinder Improve to…

– 3m2 solar hot water panel When not to recommend…

– Thatched roofs – Combi-boiler (no separate cylinder, although integration

is possible) – No real reasons to suppress, specification and

installation feasibility will be assessed by the installer

– SWH systems use heat from the sun to provide hot water for homes – The technology is well developed, with a large choice of equipment to suit many

applications – Used and sized correctly for the household, it can provide 40-50 per cent of hot water

needs over a year – One of the most cost-effective, affordable renewable technologies for housing – Suitable for use in urban and rural environments

There are two main collector types: flat plate or evacuated tube.

– Evacuated tubes are more efficient. However, they are also more expensive

– Flat plate collectors are cheaper but due to their lower efficiency, a larger collector area may be required to yield the same amount of energy

– Typically a 2-5m2 panel is mounted on a south facing roof

– Low running costs; and systems normally come with a 10-year warranty

– Solar trade association

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Double glazing Recommended for:

– Dwellings with single glazing or less than 51% double

– Improve to:

– Double glazing (U-value <2.0) – IF double glazing has been suppressed by the user

then secondary glazing is recommended as an alternative

– Specified to building regulations minimum standard When not to recommend:

– Planning constraints (listed property or conservation area) and historic buildings

Solid wall insulation

Recommended for: – Solid walls, stone or brick selected with ‘as built’ or

‘unknown’ – Main property and extensions

Improve to:

– Building regulations minimum (around 50mm) When not to recommend:

– Signs of water penetration (as opposed to condensation or rising damp)

– Poor pointing – Exposed site – Listed or property in conservation area

Typical annual saving £290 to £350 per year, installed cost from £1800

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Internal wall insulation – Internal insulation typically consists of either dry lining in the form of a laminated

insulating plasterboard (known as rigid insulation board), or a built-up system using insulation between a studwork frame.

External wall insulation

– External insulation systems are made up of an insulation layer fixed to the existing wall (using a combination of mechanical fixings and adhesive, depending on the insulation material used) and a protective render or cladding finish.

Condensing oil boiler Recommended for…

– Dwellings with oil warm air systems – Dwellings where mains gas is not available

Improve to… – Band-A condensing Oil Boiler (combi or regular)

When not to recommend… – Flats etc… where there is not sufficient space

to install a heating oil tank. Band A Mains Gas condensing boiler Recommended for…

– Dwellings heated by gas fires (no fuel switch) – Dwellings with no heating systems, or heating

systems which presently have higher CO2 emissions (fuel switch from LPG, Oil, Solid fuel and electric)

Improve to… – Band-A condensing gas boiler

When not to recommend… – Mains gas not available – Existing heating system is brand new

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Photovoltaics The capital cost of PV systems is high, but maintenance and running costs are low compared to grid supplied electricity. PV is suitable for use in both urban and rural environments.

Recommended for…

– Houses and bungalows with less than 1.0 kWp Improve to…

– 2.5 kWp in total When not to recommend:

– Listed or property in conservation area.

Wind Turbine Recommend for:

– Houses and bungalows only Improve to:

– 1 Wind Turbine • Blade diameter 1.75, hub height 2.0m – i.e.

micro-wind building integrated When to recommend:

– Dense Urban Areas • Performance and energy output of turbine

depends significantly on local wind conditions and surrounding terrain type – benefit only likely in rural or sub-urban areas

• Energy Efficiency Rating must increase by more than 1 SAP point

– Listed property or conservation area BRE Tr

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Suppressing automatic advice – other circumstances Listed building & conservation area issues Planning These buildings need consideration of historic significance, performance characteristics, design and fabric. Historic homes can be treated as special individual cases in terms of energy efficiency measures expected by the building control officer. It is important to consider how the fossil fuel carbon dioxide contributions to climate change can be reduced as part of any construction work to be carried out. There is generally no reason why older homes should not be reasonably efficient, comfortable and healthy. For modest costs, energy efficiency features may quickly save you money (especially as fuel prices are expected to rise significantly in the future), and in some cases will extend the useful life of the building. With historic properties, the Building Control Officer can adopt a ‘reasonable’ approach, as set out in the Building Regulations, to balance conservation of fuel and power against the need to conserve the fabric. It is important that any changes made avoid potential condensation problems. Sometimes it can be reasonable to upgrade the fabric, especially when undertaking extensive work anyway. On other occasions however, it can be totally unreasonable to upgrade floors and windows, for example. Listed buildings In England and Wales, listed buildings are classified as: Grade I - Buildings are of exceptional national significance Grade II* - Particularly important building of more than special significance Grade II - Special interest, warranting every effort to preserve them. Scotland and Northern Ireland use similar grades, classified as A, B and C. Contact the local planning department (which may have a Conservation Officer) to determine the specific legislation requirements for any work proposed to historic homes. The type of work requiring listed building consent varies with the building classification. Conservation areas Buildings located within a conservation area are usually part of the character and history of the area which are intended to be preserved. Planning controls will apply – seek advice from the local planning authority early on in the feasibility process. The conservation officer and designers Working with the local conservation officer and a specialist design consultant will ensure you follow the correct path of action for a project. The Society for the Protection of Ancient Buildings (SPAB) is able to give names to the public over its ‘free’ technical advice line. This operates between 9.30am and 12.30 pm on weekday mornings (020 7456 0916). Existing fabric We are only temporary guardians of historic homes, and therefore it is vital that their unique character is not at risk from unsympathetic alterations, unnecessary intervention, or changing environmental conditions. When considering the refurbishment of a historic home, it is the

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owner’s responsibility to ensure that any work does not cause unnecessary or unlawful damage to the building (fabric and indoor building environment). An older building needs to ‘breathe’ through the entire envelope to allow moisture to escape thereby preventing damp. This is especially true of historic buildings. As all buildings have unique environmental characteristics, it is important that they are understood through evaluation. This will avoid misguided material changes having a detrimental affect to the building’s breathability. At the start of the initial planning stage of the project, specialist guidance should be sought from the owner’s local building conservation officer and perhaps at least one other specialist organisation. Detailed general rules are not appropriate for individual historic properties, but as a starting point, preparation work should include: a. A good understanding of the building’s historic significance (refer to the Listed Building Description or Conservation Area Designation if applicable) will help to ensure a sympathetic approach to the planning of all work to the existing building materials and structure. b. Assessment of building heating and ventilation performance needs. c. Minimal intervention approach when planning work to the building. d. New work designed to be reversible if possible by future generations at a later date. Bear in mind that modern homes use physical barriers to stop moisture from penetrating the building envelope, whereas older homes tend to be made of porous* materials and are permeable. Modern materials such as concrete or plastic, used in older homes are often inappropriate, damaging visual and durability characteristics. * Be aware that there is an important difference between porosity and permeability:

• Permeability is a measure of the rate at which a liquid or vapour passes through a solid material. Pores must be interlinked.

• Porosity is the ratio of the volume of pore space to total volume of a solid material. Pores may or may not be interlinked.

Ventilation and draught-proofing Draught-proofing can be worthwhile for some older dwellings. However, it can lead to increased moisture levels and cause serious problems with dampness. This commonly results in mould growth and rot damage in a building that perhaps had a stable ventilation rate for hundreds of years. Typically with historic homes, moisture from the building walls and ground floors evaporates into the building. In these cases, heating with adequate ventilation to allow the moisture to escape, is how historic homes have survived with dry and healthy rooms. It will be necessary to deal with this issue in different ways, depending on the age and characteristics of the building. Seek specialist advice and see SPAB information sheet No. 4. An air-pressure test can be used to assess the property air-tightness before and after any changes to draught-proofing, if it is considered to be appropriate. Insulation In historic homes it is not usually possible to achieve a uniform level of insulation to therefore reduce the risk of ‘cold-bridging’. Weigh-up the advantages and the disadvantages of upgrading and using particular insulation materials should be considered. Some insulation materials allow moisture to escape, particularly natural insulation materials, but these often require greater

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thickness to achieve the same thermal performance of modern artificial high performance insulation materials. Heating and services Building services can be a particular problem in historic homes as pipes, wiring and heat emitters and controls are changed frequently. Services by nature tend to need ruthless access to all main rooms and penetrate the historic fabric. Beware of causing further damage and consider re-using existing services that can perhaps be upgraded or repaired. Old services that are no longer required, such as an old light switch or radiator, can often be retained as a feature and an architectural record. Once these are gone, however, it is difficult and expensive to replace them. Selection of an efficient boiler can be done by visiting www.boilers.org.uk where efficiency is used to rank boilers with efficiency bands. Manually controlled heating systems can raise internal temperatures quickly and for unnecessary lengths of time. Thermostat controlled heating can prevent wasted energy and ensure that the building maintains a reasonable environment. Underfloor heating is often best used with lime concrete expanded clay aggregate. It is normally possible to avoid using a damp proof membrane in ground floors, as this will force moisture to the walls and will rot any timbers forming the wall frame. The energy used by lighting and household appliances is significant, so use energy efficient lighting and A-rated appliances wherever possible. Asbestos Be aware that older homes are more likely to contain asbestos in various forms, such as boarding materials, ceiling finishes and insulation to pipes. Asbestos was used widely from the 1930s to the mid 1980s. If work disturbs materials containing asbestos, then the risk is a serious issue. Surveyors will be able to identify most types of products that contain asbestos, but it is really a task for specialists. If in any doubt, contact the Health and Safety Executive (HSE) and refer to the free asbestos leaflets on the HSE website. According to the HSE, at least 3,500 people in Great Britain die each year from asbestos-related lung cancer. Bats The Wildlife and Countryside Act 1981 protects bats and their roosts (and the access points to roosts) in England Scotland and Wales. Free advice can be obtained from the local Statutory Nature Conservation Organisation. The Bat Conservation Trust has helpful information on their website: www.bats.org.uk.

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