RDSAP Manual March 2012

Transcription

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2 Contents Section Introduction Section Energy rating and the EPC Section The RDSAP software Section Property features Section Constructions Section Space heating Section Water heating Section Renewables Section Recommendations

3 Section one Introduction Welcome to this latest release of RDSAP Training Manual. We hope that you find it easy to follow and simple to use. This version of the manual has been produced to coincide with the introduction of the RDSAP 9.91 methodology in April 2012, which brings some substantial changes over previous versions.

4 How to use the Manual This manual contains much of the technical information you will need during your training and assessment for the Domestic Energy Assessor (DEA) qualification. However, we may provide supplementary guidance as required in the form of additional handouts. Additional information may also be provided from time to time by other means, such as by . It is advisable to add any supplements to the manual binder because once you are qualified it will be up to you to maintain your knowledge of the latest conventions. The energy assessment industry is a fast developing one and changes are inevitable and regular. It is strongly recommended that you read more widely than this manual on some technical areas such as, for example, building construction. While the basics are covered here, you may wish to continue to increase your understanding of residential construction technology in order that you feel competent to inspect the full range of residential property. A current reading list supplied in Appendix 2 at the end of this manual. Becoming qualified is not just a matter of learning the technical aspects of RDSAP. There are other aspects to consider such as understanding the regulatory framework within which DEAs operate. This manual can be interactive, and in fact, we have deliberately made space available for you to scribble away so please feel free to make whatever notes, reminders or diagrams you need to within the pages. Just make sure that your notes are legible and technically correct as the manual will be a useful point of reference, not just during training, but also for information in the future. There are often times when it is useful to confirm your instincts with a quick check in the manual. The manual is divided into a number of clearly laid out Sections relating to major subject areas, e.g. heating or construction. Within each Section there are sub-sections containing subjects that are referred to in the contents page, for ease of location.

5 2. Section two Energy rating and the EPC History of energy rating Energy rating of buildings is not new and it has long been known that as much as 27% of our total CO2 emissions come from our homes. SAP is used to produce energy ratings for new homes. RDSAP The Reduced Data SAP (RDSAP) is the government approved survey system used to produce the Energy Performance Certificates (EPCs) required by 2002 European Energy Performance of Buildings Directive (EPBD), which came into force in The EPBD seeks to reduce the amount of CO2 which is emitted as a result of heating, lighting and providing hot water to UK homes, many of which have remained poorly insulated. With certain exceptions an Energy Performance Certificate (EPC) is required whenever a residential property is sold or let and is currently valid for 10 years. The EPC gives prospective buyers and tenants up- front information about the energy efficiency and running costs of the property they are considering occupying. The rating system that the EPC illustrates means that they can compare one property against another before choosing and, it is hoped that landlords and vendors would feel some pressure to upgrade their properties to make them more marketable and thereby some progress could be made in reducing the levels of CO2 emissions. The physical RDSAP survey of a home required to produce an EPC is a non-invasive inspection. The DEA is not required to lift carpets to see the floors or to drill holes in the walls to see the insulation and is therefore limited in what they can see of the property. There may be some reliance on documentary evidence instead. RDSAP produces an EPC that, on its front page, shows an eye-catching and easy-to-read graphical illustration of the energy performance of the property similar to the labels displayed on white goods.

6 The EPC The page 1 of the EPC shows the energy efficiency rating graph which illustrates the current rating (on the graph above of 49 or band E) and the potential rating (above of 75 or band C) that the property could achieve if the recommendations contained in the report were implemented. The graph starts at 1 in the red bar and extends to 100 in the dark green and represents the cost to the occupant of heating, lighting and hot water for the property. A low number in the red is an inefficient property and a high number in the green is an extremely efficient one. It is possible for a property to score above 100 but this is extremely rare and would normally involve exporting energy gained from a renewable energy system. It means that the cost of the energy consumption of the property is more than met by the income obtained from exporting surplus energy. On the front page the EPC will also provide an indication of the costs of providing heating, hot water and lighting to the property over a three year period along with a clear indication of the financial incentive to implementing the recommendations, i.e. the savings that could be made. It is important to note that these costs will not necessarily correlate with the occupant s billing history because RDSAP uses standard occupancy assumptions that may not reflect actual occupancy of the property.

7 Standard occupancy Standard occupancy is an important concept in energy rating because, in order to provide a means by which readers of an EPC can compare one property with another, a level playing field must first be achieved.

8 For example, you might inspect a five-bedroom house occupied by a single person whose running costs are lower than if the property were occupied by a family of five people. Conversely, you might encounter a large family inhabiting a very small flat and who use a lot of hot water and considerable heat. The RDSAP rating ignores the occupants and their behavioural patterns, focusing instead on the dwelling itself; its fabric, heating, lighting, etc. RDSAP works by measuring the annual cost of maintaining an acceptable temperature regime in a dwelling. The assumption is that an acceptable regime would be achieved by heating the property to 21 degrees Celsius in the lounge and 18 degrees Celsius in other habitable rooms for 9 hours per week day and 16 hours at weekends. The calculation uses the size of the property to estimate a suitable average number of occupants and hence the hot water requirements for that number of occupants. This method is sometimes referred to as an asset rating. Recommendations The subject of recommendations is dealt with in more depth in Section nine of this manual. The EPC presents the reader with recommendations for improving the fabric of the building, the heating, lighting and other areas. The top three recommendations are shown on the first page of the report (see below). There is also a first reference to the Green Deal in this section. The improvements suggested help to prioritise the different ways of saving energy, illustrated over a three year period.

9 Some improvements make obvious economic sense, and others are really only realistic considerations when a particular item requires replacing. Loft insulation and hot water cylinder insulation, for example, are obvious improvements, as they are cheap to purchase, can be easy to install, and often save enough energy to produce real savings in less than a year. On the other hand, double-glazing and a replacement central heating boiler are examples of improvements that cost far more, and this means that they often will not be replaced unless there is the need, i.e. a broken boiler or rotting/leaking window frames are present. The idea is to present the homeowner with enough information to help them decide on the best value for money when investing in energy efficiency. The recommendations report offers an independent comparison of the options for example: installing new double-glazing (often only adding 2-4 SAP points) with a new boiler and controls (which could easily add in excess of 10 SAP points). The running costs associated with the ratings can also help the consumer to identify the best ways to target their money to reduce fuel bills. Energy efficiency measures do make sense for cost and comfort. A typical 1960s house could have its fuel bills reduced by 200 per year for an expenditure of about 500 an effective rate of return of 40% tax-free and inflation proof. Warmer, less draughty properties are generally more comfortable to live in and may command higher prices when sold or rented. Furthermore, our understanding of the ill effects of carbon dioxide and other pollutants on our environment should be reason enough to act.

10 Other information on the EPC Page 2 of the EPC also contains basic details of the property s construction, levels of insulation, heating system, hot water system, lighting and other features and these are given an easily interpreted star-rating, depending on how efficient they are deemed to be. It is important that DEAs record these elements accurately during their inspection. Page 2 also shows details of any low and zero carbon technologies present. Page 3 (detail above) contains the full set of recommendations and an indicative cost for each, together with suggested savings per year. The green ticks suggest the measure could be applicable for Green Deal funding and the orange tick suggests partial Green Deal funding. Page 4 of the EPC (detail above) shows the environmental impact rating graph which illustrates carbon emissions associated with the property, expressed in tonnes of carbon dioxide produced per year.

11 Page 5 of the EPC (detail above) shows the details of any Green Deal charge associated with the property, including details of the installed measures, in this case loft insulation and double glazing, their monthly costs and savings, balance to repay and the interest rate charged. Survey of the property Data collection Consider for a moment what it is that you are actually doing when assessing the energy performance of a property. An input of heat is needed to replace the heat lost through the envelope of the dwelling. Some of this comes from natural solar input or is generated by the occupants, but most of it has to be supplied by the heating systems. So the DEA collects information on those characteristics of the dwelling which influence the heat loss; as well as the characteristics of the heating system. While learning the process of inspection you can follow a survey form which will prompt you with the data items you need to record while at the property. Take care not to miss anything at the property as doing so may mean you are forced to return again later. When completing the survey forms, make your entries clear and if you do not use a section strike a line through it to show that you have not simply forgotten to complete it. For example, if there are no extensions strike a line through the section of the form that relates to extensions.

12 Your site notes or survey forms are very important, firstly as a vital part of the training and assessment process, but also (once you are qualified) as part of the auditing process that DEAs are subject to by all accreditation schemes. You are obliged to maintain your site notes for a period of no less than 15 years. It is perfectly possible that you could be challenged on your findings long after the EPC was completed and your notes must be good enough to defend your position in this event. You will collect information on the building, the age, construction and insulation present in the dwelling, together with information about the heating and hot water systems and any renewable energy systems. Your survey forms should provide supporting evidence to back up any decisions you make. For example, it is not good enough simply to state that the property was built in You must provide sufficient evidence to allow an auditor (or other reader of your notes) to be confident in your decision. Did you see the deeds and photograph them? Did the planning office provide a date? Did you rely on stylistic clues and if so what were they? The thermal envelope In order to calculate the heat loss of the property, the software needs to know the area of the walls, the external wall thicknesses, the floor areas, and the roof area (assumed to be the same as the floor area) together with details of any insulation present. The assessor measures these areas as well as the room height and the length of the heat loss walls. The subject of property measurement is covered in detail later in this manual. Results of thousands of previous energy surveys allow the software to accurately estimate the area of the windows for a property of any type and age without the need to actually measure the windows, in most cases. It is necessary that the assessor follows the conventions so that all DEA end up with the same result.

13 U values DEAs using RDSAP are not required to calculate U-values, but some understanding of them is important because the option of entering U values directly to the software is available if the assessor is presented with documentary evidence that fully supports the U values entered. U-values are numbers with units of W/m2K (Watts per metres squared Kelvin), e.g W/m2K. The U-values tell us the rate of heat loss of a wall, window, floor, etc. A built element with a larger U-value will have a higher rate of heat loss, so the built element will leak heat more quickly. The heat loss through the fabric of the building depends upon the construction method; material and thickness of each part of the envelope; and upon the area of that part. By collecting descriptions of the building age and construction, the energy rating software can assign a suitable rate of heat loss and U- value to each built element of roof, wall, floor etc. It can do this because the U-values are usually characterised by the building procedures of the period and (since 1966) by the energy design standards demanded by successive upgrades of modern Building Regulations. However, what the software needs to know is whether any changes to the insulation standards have occurred since the property was constructed. So for instance, a house built during the period of has an assumed wall U-value of 1.0. If the wall has had cavity wall insulation fitted the improved U value falls to 0.40, a reduction of 60%. Such an insulation upgrade will substantially improve the EPC rating. RDSAP age bands are considered in Section Four of this manual. Heating systems The annual cost of providing heating (including water heating) to a home depends upon the amount of energy required to maintain the set standard of comfort, after allowing for the heat losses, the efficiency of conversion of energy to useable heat, the quantity of fuel needed to provide the energy, and the price of fuel. It will also be reduced or offset by the presence of any renewable energy system. Information is needed on the type of the primary heating system; details of the primary heat source (e.g. the central heating boiler); the fuel used (including for electricity the tariff, i.e. on-peak or off-peak); the use made of secondary space heating systems; the type of water heating system; the type of hot water storage, if any; as well as types of controls and renewable energy systems incorporated in the space and water heating systems. Heating is considered in more detail later in this manual.

14 How does the software use the data? The software process When the DEA enters data into the software, it then uses the input data, combined with its built-in defaults, to carry out the calculations. The output of this calculation is the predicted running cost for the home under standard. The predicted running cost is then divided by the floor area of the home and this figure is then converted into an energy efficiency rating and an environmental impact rating, somewhere on the A to G scale. The calculation is then used to estimate the savings from installing energy efficiency improvements, so that the energy advice report can make recommendations for improving the home and give a predicted potential rating if they were to be carried out. The Landmark Register The report is produced, reviewed by you and finalised when you are happy that its content can be finalised. Once finalised you cannot later change the report or its content. Once you are qualified, your EPCs will automatically be lodged on the Landmark Register where all EPCs are stored. During training and assessment you will not be able to lodge reports and do not have to worry about creating a real EPC for a property. You are able to practice with the software as much as you need to.

15 3. Section three RDSAP software To Produce EPCs you need to use one of the softwares provided by different accreditation schemes. All softwares use same conventions and methodology. While training you will have access to a training account which will allow you to use most of the features of EPC online but will stop short of allowing you to produce real EPCs. You are able to practice with the software without fear of actually creating an EPC for a property. The software that you will use at this stage is essentially the same as the live software that you will use once qualified. Purpose of EPC Marketed sale Non-marketed sale Rental (social) Rental (private) This option should be used for EPCs required for marketed sales (known as single survey in Scotland). This option should be used for Right to buy or sales that are not advertised. For example the sale of a house by one family member to another. This option should be used for dwellings owned by social landlords; this could be local authorities or housing associations. This option should be used for rental EPCs from the private sector. Institutions such as universities will fall into this category. Not sale or rental This option should be used if the EPC regulations do not require and EPC for the dwelling, for example, if a homeowner wanted an EPC just to see how energy efficient their dwelling is. There is a field on this page that asks if the report is created from existing data. This refers to the practice of cloning, whereby data is used from previous EPCs. This practice is outside of the scope of this manual and requires additional training. Further information may be gained by contacting NES. Consequently that field and the next, which asks for a reference number, should be left blank.

16 General details Here you are required to enter some fairly self-explanatory information about the property such as the detachment, the number of storeys and the number of extensions. You will be asked whether you measured internally or externally. Internal or external measurements The measurements required are: The floor area The exposed perimeter Room height on each storey Exposed perimeter includes the wall between the dwelling and an unheated garage or a separated conservatory and, in the case of a flat or maisonette, the wall between the dwelling and an unheated corridor. Internal dimensions are permissible in all cases. When using external measurements for a dwelling joined onto another dwelling (semi-detached and terraced houses) the measurement is to the mid-point of the party wall. Flats and maisonettes are usually measured internally. Whichever is chosen the same basis must be used for all parts of the dwelling. Room heights are always measured internally within the room, from carpet level to ceiling. The software automatically makes an allowance for the thickness of intermediate floors.

17 The ground floor area must not include any: Integral or adjoining unheated garages (a heated garage is defined as one which contains fixed heat emitters linked to a main/central heating system) Stores, coal sheds or other external (thermally separated) unheated spaces Thermally separated conservatories Unheated, thermally separated porches Terrain type The terrain type must be recorded for every survey. This allows the software to assume an average wind speed for the area. The average wind speed is used in the calculation of the benefit of a micro wind turbine. Even if a wind turbine is not present the terrain type must be recorded to enable the software to assess whether a recommendation for a wind turbine is viable. See the table for the choices and note that unless you are in a city centre location, suburban is the most common choice. Dense urban City centres with mostly closely spaced building of four storeys or higher Suburban Towns or village situations with other buildings well spaced Rural Open country with occasional houses and trees Mains gas available If there is a gas meter at the property or a mains gas appliance then you need to record that mains gas is available. The fact that there is a gas supplied to other properties in the street does not mean that mains gas is available to the property you are inspecting. Number of rooms and habitable rooms The software asks for the number of habitable rooms and whether any of these are unheated. Habitable rooms include any living room, sitting room, dining room,

18 bedroom, study and similar; and also a non-separated conservatory. A kitchen/diner having a discrete seating area also counts as a habitable room. A non-separated conservatory adds to the habitable room count if it has an internal quality door between it and the dwelling. 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. For open plan dwellings count all spaces thermally connected to the main living area (e.g. a living/dining room) as one room. For a kitchen to be a kitchen/diner it must have space for a table and 4 chairs. A lounge/dining room where the door was temporarily removed (i.e. architrave and hinges still there) is two habitable rooms. A lounge/dining room with the door permanently removed (hinge holes filled etc) is one habitable room. Flats and Maisonettes Note that flats are dealt with in more depth in Section Four. Semi-exposed elements This page asks for details of the flat or maisonette you are entering and will simply not apply if you are dealing with a house. If you are entering a flat you will need to enter the flat type; that is whether it is a basement, a ground floor, mid floor or top floor flat. You will also be asked to enter the flat s position in the block. If it is a first floor flat, the floor position will be 1 and the software helps you by providing the choices. Under semi-exposed elements the software asks if there is a corridor and, if so, what type and what length. A more detailed explanation of this and some examples is contained within Section Four of this manual.

19 Age and roofs Unknown or asbuilt Depending on the element, you will have the option of entering the insulation as being as-built or unknown. Using either will mean that the software defaults to the insulation depth that apply according to the date you have entered for the property s (or extension s) date of build. However, with unknown there will not be a recommendation for further insulation. (Take for example a roof in a 1900 terraced house, over the page.) If you are unable to access the loft you might enter that the loft insulation is unknown. The software will assume the roof is insulated as it would have been when new (in 1900 that would be none) and there will then not be a recommendation for increasing the insulation. This is because the roof has not been assessed for its suitability; there might be a condensation problem or there might already be 300 mm of insulation. This does illustrate why it is so important for the DEA to make every effort to inspect the roof space where possible. Choosing as-built for a wall for example, means the wall is as it was when built. For a 2007 house cavity walls as-built means the walls are built to 2007 Building Regulations and will therefore be insulated. Property age Property age is extremely important to the software. The property age is required for the software to select the default heat loss values (U-values) for the wall, roof and floor and to calculate the window area. Clearly properties of different ages will perform very differently and the general rule is that the newer the property is the better the U values of its component parts. Houses of different ages also have different window to wall and window to floor ratios. The age bands for newer properties correspond to changes in Building Regulations and the older age bands, pre-1966, with changes in methods of building. The RDSAP age brackets are as follows and the job of the DEA is use their best efforts to date the property accurately and place it in the correct age band. Age bands Pre-1900 A E I B C D E F G M J 2007 onwards K

20 Property age and how to date property is further covered in Section Four. Roofs RDSAP deals with roofs on the main property and any extensions. Each is entered separately, starting with the construction type. Roofs types, their insulation and the options available in the software are described in Section Five page 24. walls and floors This section deals with walls and floors and their insulation levels. For both, this is where you will enter the construction type, insulation type, insulation thickness and any U values that are known. For walls the overall thickness of the wall is required and whether there is a dry lining. Note that walls and floors are covered in detail in Section Five. Aalternative wall This section of the software relates to alternative walls only and you will simply leave the section untouched if there is not such a wall at the property. You would enter an alternative wall type where the property has a significant area of wall that is of different construction or insulation level than the building part it belongs to, but this wall type cannot be identified as an extension since it does not surround any floor area. Where an area of alternative wall exists but it constitutes less than 10% of the total external wall area of the building part it belongs to, it can be ignored. The 10% of the wall area is identified including the windows and doors; it is only when measuring to the area of wall calculate the area to be included into the data summary that the area of any windows and doors is subtracted. This means that if you believe there to be an alternative wall then you will have to measure any window and door openings. Alternative wall types can occur as part of the main house, or part of any extension and you should record which of these applies. It is possible to enter up to five alternative walls. Note that alternative walls are dealt with in detail in Section Four.

21 Left: The tile hung area of the wall might be alternative, if you can determine its construction to be different than that of the rest of the house. In this example, it looks to be approximately 10% of the total wall area, but further measurement is required. Dimensions The software requires the following data for the main property and each extension: The floor area in metres squared. The room height in metres to the nearest centimetre. The heat loss perimeter (HLP) in metres. See Section Four of this manual for detailed RDSAP measuring conventions. Rooms in the roof Note that roof rooms are dealt with in detail in Section Four. This section of the software deals with rooms built within the roof space of a property and the section will simply be ignored if there is not one at the property. A room in the roof is a habitable room built into what would normally be a loft space, above the main part of the dwelling, or above any extensions. Note that for such a loft space to qualify as a room in the roof for energy assessment purposes, it must incorporate fixed staircase access, i.e. not just a loft ladder. It will usually have sloping ceilings for part of the area and may also include dormer or Velux windows. If a roof room is present, the software requires you to enter the age range, floor area and the details of the insulation present. If you are able to obtain documentary evidence of the U-values of the component parts, you can enter this information in the extended data section on roof rooms (see Section Four).

22 Openings windows Note that windows and glazing are dealt with in detail in Section Four. This section of the software deals with the openings in the property created by windows and also by any open fireplaces and ventilation systems. Details of any draught proofing are also entered here. The software asks that you enter whether the window area is typical of that type of property or whether it is more or less than typical. It also asks that you enter the proportion of the property s window area that is multiple glazed if any and what type of multiple glazing is present. if 60% of the area (including the frame) of a door is glazed, they are treated as windows. Open fireplaces On the same page of the software in the ventilation section you are asked to enter the number of open fireplaces. These contribute greatly to the ventilation of the property and will remove some of the warmth generated by the heating. Note that open fireplaces are dealt with in detail Section Four of this manual. Ventilation The software asks you to enter the ventilation method and the options are: Natural ventilation this means the property is ventilated in the traditional way by windows and possibly vents in the walls and windows. Mechanical, supply and extract this is a whole house mechanical system which both introduces fresh air into the property and extracts heat from the stale air. Bathroom and kitchen extractors DO NOT qualify as mechanical ventilation. Mechanical, extract only this is a whole house ventilation system which mechanically extracts stale air from the property passive vents or gaps in the fabric of the building. This is sometimes known as MEV. Bathrooms and Kitchens extractors do not get classed as MEV. Air conditioning The presence of air conditioning in the property simply requires a box to be ticked in the software. Extended openings This section is for use when there is much more or much less than typical areas of glazing at a property and enables the location, dimensions, glazing type, orientation, U value and g value of each window to be entered individually. See also Section Five.

23 Space heating Main heating systems This important section of the software deals with the MAIN heating systems within the property. It is possible to enter either one or two main heating systems and apportion the amount of work each does in maintaining the acceptable heating regime that was described earlier in this manual. The Product Database which contains specific technical information on a wide range of heating systems is located in this section of the software. Searching it for a system just requires clicking on the appropriate tab. A number of entries are required about the main heating systems and given the complexity and range of possible entries, these have been covered in the heating section of this manual (Section Six).

24 Electric meter See Section Four of this manual for more about electric meters. The first entry to be made in this section is to describe the electric meters present. The choices are: Dual rate Single rate Unknown 24-hour Heating systems Details of any secondary heating system are required including the fuel and system type. For a detailed definition of what a secondary heating system is please see Section Six of this manual. water and secondary heating The secondary heating system should be entered next and this important area is covered further in Section Six. Details of the water heating system should be entered in this section of the software, including the heating type, system, fuel and immersion heater type, if applicable. If there is a hot water cylinder, its size, insulation type and thickness and whether there is a cylinder thermostat should be entered. This is covered in more detail in Section Seven of this manual. Bath and shower details are also recorded in this section, as follows: Number of rooms with bath and/or ANY shower Rooms with MIXER shower AND bath Rooms with MIXER shower and NO bath This enables the software to make the appropriate recommendations in respect of waste water heat recovery systems (WWHRS). Heat recovery systems This section of the software asks for the number of waste water heat recovery systems (see section 6 for details) and also allows for two flue gas heat recovery systems (FGHRS) to be entered. Both systems have their own Product Database which allows for searching for and selecting specific models.

25 Conservatories and lighting If a conservatory is present at the property, its type must be recorded and if non-separated the floor area, whether double glazed, the glazed perimeter and the number of storeys in height it covers should be entered. See Section Four of this manual for a detailed look at conservatories. Low energy lighting Low Energy Lighting includes CFL, LED and fluorescent tubular lighting. You need to record: The total number of fixed light outlets. The total number of fixed low energy lights. Section Four of this manual explains low energy lighting in more detail including the conventions on counting combinations of lights. Renewables This section covers renewable energy systems; notably wind turbines, solar photovoltaics and solar hot water. Renewables can require some complicated software entries and these are covered in detail in Section 8. Addenda This section in the software enables the DEA to better describe the property s features within the format of the report by allowing certain anomalies to be explained to the reader. These include statements that explain that there are wall types that do not correspond to the options available in RDSAP and the presence of swimming pools. This section is the last of the data input screens and clicking next at this point will take you to the Results: Recommendations section. The list of addenda is some optional statements that can be added to the EPC if required. They describe situations which as yet cannot be modelled in the software. The aim is to reduce complaints from householders about features that are not adequately described on the EPC. The list of addenda is currently as follows and is occasionally updated. In case you are wondering why the list is numbered 1, 4, 5, 6, 8, 9, it is because the missing numbers from this sequence represented addenda that have now been removed from the list because the software has developed to the point where it can deal with those issues. The screen shot below shows section P15 of the RDSAP software which allows the assessor to select addendum.

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27 Results: Recommendations screen If you have fully completed each section so far, then at this point you will see a SAP Result expressed as a figure between 1 and 100. Also you will see a list of recommendations made by RDSAP. If the property has walls of cavity construction, there are additional questions about whether or not the cavity walls are hard to treat. That is, whether there are access issues such as adjoining conservatories, garages or other outbuildings that might make the physical installation of cavity fill insulation difficult. This could also include any situation where access by means of a 5 m high ladder is not possible such as at higher buildings or flats. Cavity fill may still be possible but will be more expensive. Cavity walls which are within areas of high exposure may be subject to higher levels of driving penetrating rain. The DEA should refer to the map below to decide whether or not the property is in an area of high exposure and if so the appropriate box should be ticked and an addendum generated. Cavities which are less than 50 mm in width may require specialist cavity insulation or may not be suitable at all. Ticking the box to say that walls have narrow cavities will produce the appropriate addenda to inform the client of this. Narrow cavities may be identified by a total wall reveal thickness of less than 250 mm, yet a stretcher bond pattern to the brickwork.

28 Property features 4. Section four Property features introduction Some questions contained within this Section only apply to flats and maisonettes. Where this is the case, it will be clearly stated in the text. Some of the question titles (for instance, the number of rooms) appear to request the obvious, but do make sure you read everything through at least once, as there are a few points to remember. Basements A basement is defined as a part of the heated and occupied area of the dwelling that is fully or partly below external ground level and where 50% or more of the external wall area loses heat to the adjacent soil rather than to the external air. In order to be included within the energy assessment, a basement must be accessed by a permanent fixed staircase such that a person can walk down it facing forwards, and it is either: Heated by fixed heat emitters, or Open to the rest of the dwelling. If recorded the basement will become the ground (or lowest occupied) floor. Note that there do not need to be any habitable rooms present in the basement. When incorporating a basement in the assessment do not mix internal and external measurements. If a basement is included in the assessment, it is likely that internal dimensions will be used throughout the dwelling.

29 Bay windows You are required to measure and enter details of all bay windows if they increase the floor area of the property. If any of the building elements of the bay are different to the rest of the house, i.e. the walls, floor or roof, then you will need to enter the bay window as an extension. Remember that an extension does not have to have been built later. The ability to enter up to four extensions gives you the flexibility to more accurately record such perturbations as bay windows. The bay in the photo is rectangular but bay windows can also be either a trapezium shape or a semi circular shape. The following diagrams should assist you in calculating the area of a bay window.

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31 Conservatories what is a conservatory? For RDSAP a conservatory is a structure with at least three quarters of its roof and at least half its external walls glazed. If the structure in question does not meet these requirements then it should be considered as an extension. The treatment of a conservatory depends on whether it is separated or non-separated from the dwelling. separated or non-separated A separated conservatory is effectively ignored for the purpose of calculating the dimensions and heat loss perimeters, although you do need to note whether or not it has fixed heaters. Most modern conservatories fall into this category; they will often have external quality upvc doors separating them from the house. As a rule of thumb, if you imagine the conservatory was removed, you would need to ask: Would the doors offer sufficient protection from the elements? External quality doors are usually thicker and have features such as double-glazing, locks, bolts and weatherproof surrounds. A non-separated conservatory will either have internal quality doors the thin, lightweight type that sometimes separate rooms, or will be open to the adjoining room. The doors may have been removed or the conservatory could have been designed to extend the room and have no doors. Consider whether the non-separated conservatory alters the number of habitable rooms. Several items of data are required about the non-separated conservatory: Floor area, measured internally Glazed perimeter (ignore areas of brick wall) Whether double glazed Conservatory height in storeys

32 Images 1 and 2 show an example of a separated conservatory, with sliding patio doors. These are of exterior quality, are double glazed, provide a good seal, and are lockable. Images 1& 2: Exterior quality door note they provide a good seal, are heavy weight and lockable. Images 3 and 4 are of a non-separated conservatory. The interior quality doors are not deemed to thermally separate the conservatory from the main dwelling. Although it is not visible from the images, these do not close properly owing to the lack of wooden trim to the frame, the latches are missing and they do not lock. Images 3 & 4: Interior quality doors note they do not shut properly and do not provide a good seal to the doorway.

33 To recap: In RDSAP there are four options for conservatories: A non-separated conservatory is like an extension in that the heat loss perimeter of the house does not include the length of house wall next to the conservatory. This is illustrated in the diagrams below. Conservatory No conservatory Separated conservatory, no fixed heaters No conservatory present either separated or un-separated. A separated conservatory is present, but there is no heating or only portable heating Separated conservatory, fixed heaters A separated conservatory is present and is heated by fixed heaters which may be from the main heating system. Data for nonseparated conservatory A conservatory that is open to, or separated Non-separated by internal quality doors, the main dwelling. conservatory Record the area, height, glazed perimeter and whether it is double glazed. The exposed perimeter for the conservatory should be measured in the same way as for the main house and extension but it is the length of exposed glazed wall that is required. If there are areas of brick wall, these can be ignored. This is illustrated in the diagrams below. Remember to indicate if the conservatory is double-glazed and to estimate the average height of the conservatory relative to the main dwelling storey height.

34 example 1: In this case, the conservatory floor area is 15 m2 and the glazed perimeter is 11 m. House with a non-separated conservatory House heat loss perimeter is: = 25 m Conservatory glazed perimeter is = 11 m Conservatory floor area is: 3 x 5 = 15 m2 In this case, the floor area is 15 m2 and the glazed perimeter is 11 m. example 2: In this second example, the conservatory floor 2 area the glazed is 12 m and perimeter is 7 m. House with garage and nonseparated conservatory House heat loss perimeter is: = 25 m Conservatory glazed perimeter is = 7m Conservatory area is 3 x 4 = 12 m2

35 It is important to note that when calculating house floor areas and that you do not include within these the area and glazed HLPs perimeter of the conservatory. what if the conservatory is not a conservatory? It is not uncommon to find a conservatory that does not meet the RDSAP definition of such; i.e. a structure that does not have half its walls and three quarters of its roof glazed. Garden rooms may have a traditional flat or pitched roof. In these circumstances the structure should be treated as an ordinary extension except that you may need to make use of the more than typical glazing feature of the software which is discussed in the section on windows further on in this Section. passive solar design and sun rooms Separated conservatories provide shelter to the external wall, and also capture solar heat, which will partially warm the house. For most conservatories this effect is very small and both the solar heat gain and the sheltering effect are ignored in the RDSAP energy rating calculation. Some homes have exceptionally large unheated conservatories covering more than one storey and designed as a solar space to deliberately capture solar gain and pre-warm the home. These properties can be recognised by the fact that the conservatory will often extend to the full height of the dwelling and will make up a large proportion of the dwelling floor area. This can be dealt with by using one of the more than typical glazing options see the section on windows. An example is shown in the image below.

36 Detachment Whether the property is detached, semi-detached, terraced or built in another form is important to the software so that it can select the appropriate set of default assumptions, including the pattern of window openings/glazing that should apply. Your choice of detachment will appear on the front of the EPC report. The options are described below. Detached Houses that are described as detached have no party walls and so have exposed wall area on all four sides. Here are some examples. Link detached houses (houses that are essentially detached and are only linked to neighbours by a garage) should also be classed as detached. semi-detached Semi-detached houses share one side (the party wall) with a neighbour. This leaves exposed wall area on three sides. Although end-terrace and semi-detached properties are similar in terms of exposed walls there is a slight difference in the typical window areas for the two built forms. An end-terrace property will usually have a blank gable end wall, where as a semi-detached house will most likely have additional glazing in the side elevation, being glazed on three sides, rather than just front and back.

37 End-of-terrace As the name suggests this is the first or last house in a terraced row. End-of-terrace properties have three exposed sides like a semidetached, but tend to have blank end walls. This means that the typical pattern of glazing will be the same as for a mid-terrace. Mid-terrace Mid-terrace houses have two party walls (one on either side) and two heat loss sides (front and back). If the terrace has a passage through to the back of the house, classify it as a mid-or end-terrace house, include the length of the passage wall in the lowest floor heat loss perimeter and consider identifying the heat loss floor above the passageway through the extension option. Enclosed midterrace These houses are often called back-to-backs. Back-to-back properties are essentially terraced houses that also back onto another terraced row. From the street they will look just like a terraced house, but the rear of the property joins the back of a house from the next street, which gives us the phrase back-to-back. They have only one heat loss wall, as the side walls are common with their neighbours and the rear wall is common with the property on the terrace of houses at the rear.

38 Be careful if a house is described to you as back-to-back sometimes this term is used to describe terraces that are built very close together with only a narrow yard separating them. These back-to- backs are not enclosed, they are normal terrace houses. Enclosed end terrace An enclosed end-terrace will be the first or last house in a terraced row of back-to-back houses. They have two adjacent heat loss walls, and two adjacent party walls. Modern cluster homes are also enclosed end-terraces; the block is essentially four enclosed end-terraces without any mid-terraces in between. A residential property adjacent to commercial premise It is possible to record a dwelling next to a shop or office in the following way: If a dwelling has a commercial property below, record as partially heated space below. If a dwelling has commercial premises above, record as other dwelling above. If a dwelling has commercial premises alongside it, treat as a nonheat loss wall.

39 Dimensions Introduction Property dimensions are an important part of the energy rating calculation remember that the energy rating is calculated by dividing the predicted fuel costs by the floor area so it is important that the floor area is calculated accurately. Your floor area calculation is displayed on the front page of the EPC. The heat loss perimeter (HLP) is needed to assess the heat losses through the building fabric and the room height is important, since the ventilation loss depends on the building volume, which is calculated using the room height. For a simple property such as a bungalow or a flat, the actual data entry could be as few as three items floor area, room height and heat loss perimeter. For many houses, the floor area and HLP will be the same on all floors (but not the room height!), so the amount of data to input is often less than you might think. However, there are properties where the measuring can be more complicated. Imagine an irregularly shaped house with numerous extensions, bay windows, conservatory, etc; in such a case there is considerable measuring to do which will require a systematic approach. Floor plans A floor plan showing dimensions (and other property features) is essential in every case, even the simple properties. The plan should, among other data items, show the horizontal dimensions of the property, the room heights and the HLP. It is highly recommended that you highlight the HLP with a different colour, firstly to aid you in ensuring accuracy and secondly to allow someone checking your work to be able verify your accuracy. : A well-marked floor plan: The plan should also show the position of lights, windows, heat emitters and anything else that is relevant to the inspection.

40 Internal or external measurements For houses, internal or external dimensions can be used depending on which are easier to measure on site. If you measure externally, the program uses those external dimensions by adjusting them to allow for the wall thickness, but the entire survey needs to be carried out using either internal or external dimensions. Flats are usually measured internally, as is room height and room in roof floor area. You must not change between internal and external when measuring different parts of the house. Floor area At a straightforward rectangular property, the floor area is calculated simply by multiplying the length of the property by the width. By using external measurements you will be calculating the Gross External Floor Area (GEA) and by using internal measurements the Gross Internal Area (GIA). The software adjusts whichever you decide to use to GIA for the EPC report. Complicated properties will require more dimensions to be taken on site and a more careful and detailed approach to making an accurate calculation. Do not include external unheated porches in the floor area. Do not include unheated areas (such as outhouses, outside toilets, garages or coal stores) that are not accessed via an internal door, even if they are within the footprint of the dwelling. Do include unheated rooms, e.g. internal utility rooms and lobbies, so long as they are within the external envelope of the property and are accessed via an internal door. Heat loss perimeter The external or internal dimensions are used to work out the exposed wall perimeter. The exposed wall (heat loss perimeter or HLP) is extremely important for evaluating heat loss wall areas as well as the heat loss through the ground floor. Therefore it is essential that it is measured accurately. The energy assessor is required to record the heat loss perimeter (HLP) for the main house and, separately, for any extensions. The heat loss perimeter must also be calculated for each floor of the house and any extension(s) present.