Standard Assessment Procedure (SAP)
What are SAP calculations and why do I need them?
Standard Assessment Procedure (SAP) is the approved methodology used to assess and compare the energy and environmental performance of new dwellings. The Government has required all new homes, under Part L of the building regulations, to have a SAP since 1995. Its purpose is to provide accurate and reliable assessments of not only the building regulations but also all energy and environmental policy initiatives. The documents produced are used as evidence to prove the building meets Part L requirement.
How are SAP calculations made?
The SAP rating is a figure between 1 and 100+ (100 representing zero energy cost. Anything over means you are exporting energy). The higher the SAP rating, the lower the fuel costs and the lower the associated emissions of carbon dioxide. The factors that contribute to energy efficiency could be:
• the materials used for the construction
• heating energy control
• air leakage of the dwelling, and performance of ventilation equipment
• the fuel used to provide space and water heating, ventilation and lighting
• solar gains through openings in the dwelling
• renewable energy technologies
Without a SAP a property will not be signed off by Building Control and may not legally be listed for rent or sale.
In addition to new builds, an extension with more than 25% glazing-to-floor area, a barn conversion, a commercial to domestic conversion or a conversion of a single dwelling into flats or apartments will also need a SAP.
What is the process?
It’s key to start a SAP early. A design stage SAP should be carried out before the property is constructed, as it may identify changes to the plans which would lead to more expense. When the new dwelling is complete an as built SAP is produced. This document confirms all that was specified at the design stage is in place or, that any design changes have been implemented and that the dwelling still complies with SAP. From the As Built SAPS an EPC can then be issued.
Please see our section on new build EPCs.