SAP ASSESSMENT
Standard assessment procedure’s calculations are designed to measure the energy performance of all new dwellings, conversions and extensions.
What is a SAP assessment and why may you need one for your construction project?
SAP stands for 'standard assessment procedure'. SAP calculations are designed to measure the energy performance of all new dwellings, conversions and extensions. A SAP Assessment is required under the Building Regulations 2021 PartL1b to demonstrate that your new dwelling or house extension complies with Part L of the Building Regulations. SAP calculations are the Government's Standard Assessment Procedure for Energy Ratings. In order to produce an On Construction EPC (Energy Performance Certificate) or a Predicted Energy Assessment (PEA), a SAP is required, as this is the calculation these certificates are based on. The higher the SAP rating, the lower the cost will be to run the building. The score represents the cost of energy required by a property over the course of a year with a 100 score meaning there's no energy cost. To calculate the SAP, the assessor uses information relating to lighting, heating, hot water systems, renewable technologies used and the elements of structure.
Therefore, in simple terms, a SAP Assessment confirms whether the dwelling has enough insulation and does not emit too much carbon as defined by the Regulations. SAP Calculations have been a requirement in the UK since 1995 under Part L of the Building Regulations. These calculations are necessary to produce a Predicted Energy Assessment and an Energy Performance Certificate (EPC certificate). Building Regulations require that a SAP calculation and a predicted EPC is submitted for new dwellings prior to the commencement of work. SAP calculations are important to demonstrate compliance with Part L and to produce an EPC. They are also used to determine a SAP score/rating for the property.
Whilst it is a requirement under the building regulations, we at MJA recommend the SAP report is carried out at the initial planning design stage. This is to ensure that the design is compliant at an earlier stage to avoid post planning changes and thus avoiding any potential abortive work should it be found at building regulations stage there are design changes needed owing to non-compliance. It is therefore recommended that you get them done as early in your project as possible, so if your building should fail, we can can advise you on how to improve and comply.
How is A SAP Assessment Undertaken?
A SAP is assessed off-site but requires architectural plans and drawings of the proposals along with a detailed specification of the works in order to be calculated. Amongst other things, the SAP assessor will determine how good the thermal elements are in the floors and walls and how well heat passes through these elements - this is known as a 'U' value. A high 'U' value represents a high amount of heat lost - this is used in the SAP calculation.
The SAP software will determine if a building complies with Building Regulations using the information provided by the SAP assessment. This crucial information relates to the type of dwelling, floors, walls, the roof, windows, doors, lighting, renewable technologies, 'U' values, hot water and ventilation. Depending on the classification of your development will depend on the way the SAP is assessed.
-
SAP calculations are required for extensions if the proposed area of new glazing exceeds 25% of the total extension area. Building Regulations require this SAP Assessment to ensure that emission rates from the dwelling will be no worse following the addition of the extension. This is due to glazing having a lower thermal
-
Assessing the existing and proposed area of the external building fabric and openings.
Evaluating the building's current construction materials and the extension's proposed materials.
Measuring the energy consumption of the current and updated heating systems, lighting, ventilation systems and renewable technologies.
Next, we create a notional report with benchmarked data for the existing and proposed elements of the building, and a report with the proposed data for the existing building plus the extension.
Finally, we will analyse and compare the reports in SAP calculations software to make sure the data in the proposed report is lower than benchmarked standards.
-
Existing and proposed Floor plans of the property
Existing and proposed elevations of the property
A section drawing showing the height of each floor
Specification of the proposed elements e.g. wall, floor, roof & glazing
Heating system details
-
For new dwellings, the SAP Assessment assesses the building versus a 'Notional' dwelling based on the same size, shape and orientation as the proposed building, but with the building specification (U-values, window area, heating system and efficiency etc.) made up of a set of reference values to determine the target fabric and emission rates your new dwelling should achieve.
The SAP calculations come in two stages: a ‘design stage’ SAP report and an ‘as built’ SAP report. These calculations will measure a number of aspects of the building’s energy performance. However, the primary purpose of these calculations is to produce the EPC. This process includes.
-
Assessing the area of the external building fabric and openings.
Analysing the building's construction materials.
Understanding the energy consumption of the heating systems, lighting, ventilation systems and renewable technologies.
Inputting this data into SAP calculations software in order to produce Target Emissions Rates (TER) measurements, Target Fabric Energy Efficiency measurements (TFEE) and to demonstrate that the building is Dwelling Emission Rate (DER) and Dwelling Fabric Energy Efficiency (DFEE) compliant.
-
Where your new dwelling is categorised as a conversion e.g. from agricultural outbuildings or change of use from a commercial building, the SAP Assessment is only used to determine that the existing and new fabric elements (walls, floors and roof) comply with the minimum U Values required in Part L.
The SAP calculations for conversions come in two stages: a ‘notional report’ and a ‘proposed report’. These reports are then compared in order to produce an up-to-date EPC for the property.
The SAP calculations for extensions come in two stages: a ‘notional report’ and a ‘proposed report’. We compare these reports in order to demonstrate that the whole property as constructed, will meet Part L1B Standards.
-
Assessing the existing and proposed area of the external building fabric and openings.
Analysing the building’s current construction materials and the extensions proposed materials.
Understanding the energy consumption of the current and updated heating systems, lighting, ventilation systems and renewable technologies.
Creating a report with benchmarked data for the existing and proposed elements of the building, and a report with the proposed data for the existing building and the extension.
Inputting data from the proposed report into SAP calculations software. This determines the entire property’s Dwelling Emission Rate (DER) and Dwelling Fabric Energy Efficiency (DFEE) rating.
The DER and DFEE of the proposed report is then compared against benchmarked standards. For conversions to pass the SAP calculations process, the figures from the proposed report must be lower than the benchmarks
We at MJA can assess all of the above projects and help guide you towards compliance.
“We approached MJA help remodel our home, we were open to alternative ideas and they blew us away! We now have a contemporary and spacious extension that we are proud to show off.”
— Marcus and Jayne Wilkes