SAP Calculations


What are SAP Calculations? SAP Calculations are an assessment of the energy efficiency of a dwelling, produced using the UK Government approved Standard Assessment Procedure.  


The SAP calculation involves working out a property's Dwelling Fabric Energy Efficiency (DFEE) and Dwelling Emissions Rate (DER) in order to demonstrate that these are less than the Target Fabric Energy Efficiency (TFEE) and Target Emissions Rate for a building of a similar shape and size.  This allows a SAP rating and Environmental Impact rating to be produced.  


For existing dwellings, you do not need a SAP calculation.  For existing dwellings, a Domestic Energy Assessor will produce an Energy Performance Certificate using the Reduced SAP (RDSAP) process.  This is because it is not possible to obtain detailed information about the construction of an existing dwelling without damaging it in the process, so RDSAP allows average values to be used based on the date of construction of the building.  If you need an EPC for an existing dwelling, take a look at our Domestic EPC page.


SAP calculations are produced based on drawings and written specifications and do not require a visit to site. Design stage calculations are required before commencing work and allow a Predicted Energy Performance Certificate to be produced - this is needed if you are going to market your development off plan. Our standard service for design stage SAP calculations includes offering suggestions to achieve compliance if your initial design proposal does not meet the required targets. As-built SAP calculations are required prior to selling the property and allow the final SAP EPC to be generated. Our standard service for SAP EPC covers both the Design and As-built stages of the process, but we can offer Design or As-built Stage only services where required.


We can normally turn around SAP calculations within 48 hours of information being provided. The information needed to complete a SAP calculation is described in more detail in our downloadable SAP Information Sheet. We are accredited to provide SAP calculations with Stroma Certification and are able to offer this service on a nationwide basis. If you have a development that requires a SAP calculation please get in touch using the contact form opposite. We will reply with pricing information and a firm quotation can provided once details of your development have been confirmed.