Are SAP Calculations and EPC Ratings the Same Thing?

If you’ve been looking into energy rating requirements, you might have seen the terms SAP calculations and EPC ratings floating around, but what do they mean? Are they the same thing? 

In this article we go over SAP calculations and how they differ from EPC ratings. We also outline what a good SAP score is, and how they’re calculated. Read on to learn more.

What are SAP Calculations and EPC Ratings?

Standard Assessment Procedure (SAP) calculations are the methodology behind the wider-known Energy Performance Certificate (EPC) ratings. The SAP calculation falls into one of two categories; L1A (new builds) and L1B (extensions and conversions). It considers both the Dwelling Emission Rate (DER) and Dwelling Fabric Energy Efficiency (DFEE), as well as a variety of other factors, before being used to inform the EPC rating of a building. 

EPC ratings detail the energy efficiency of a residential building. It helps individuals to estimate energy costs with a ranking from A to G, with A being the most efficient. The EPC rating is particularly useful when moving home, but can also be useful for homeowners to improve the efficiency of their home. 

UK building regulations require a Predicted Energy Assessment (PEA) for all new buildings prior to commencing work. Similarly, all existing buildings must have a valid EPC rating before being sold, and the certificate must be made publicly available. 

Are SAP Calculations and EPC Rating the Same Thing?

SAP calculations and EPC ratings are not the same thing. However, SAP calculations are used to inform EPC ratings. 

A variety of calculations are conducted on new build homes, extensions, and conversions to judge the energy efficiency of the building. The EPC rating is the publicly visible rating (A-G) that is formed from the SAP calculation.

For new build homes, a Predicted Energy Assessment (PEA) will be required before work can commence. This is similarly informed by SAP calculations conducted at the design stage.

What is a Good SAP Rating

To put it simply, the higher the SAP calculation score, the better the EPC rating will be, which will result in lower energy costs. SAP calculation scores sit between 1-100+, where 100 represents zero energy costs and anything over 100 indicates that the building actually exports energy. 

EPC is rated from A-G, with A being the most energy efficient. Ratings are calculated based on SAP scores as follows:

A – 92-100 SAP points 

B – 81-91 SAP points.

C – 69-80 SAP points.

D – 55-68 SAP points.

E – 39-54 SAP points.

F – 21-38 SAP points.

G– 1-20 SAP points.

How are SAP Ratings Calculated?

A building will be judged on how it uses and loses energy across a variety of areas. Each of these areas are given a score, which goes towards the overall SAP calculation score, and the eventual EPC rating. 

  • Materials used
  • Efficiency of heating systems
  • Solar gains found through openings in the building
  • Level of thermal insulation used
  • Use of renewable energy technologies
  • Fuel used for water, space heating, light, and ventilation
  • Air leakage
  • C02 emissions

SAP Calculations in England and Across the UK

RS Energy are providers of SAP calculations in England and across the UK to help you achieve regulatory compliance efficiently, and cost-effectively. View our services here, or get in touch with our friendly team today to discuss your needs.