Find out how the new AD L will impact your upcoming developments AD L White Paper
New build residential home development

SAP Calculation

A Standard Assessment Procedure (SAP) Calculation is used to show energy efficiency compliance for new-build dwellings and is required as part of Part L Building Regulations in order to produce an EPC for the sale or rental of a residential property.

How can Energist help

SAP calculations are changing.

Stricter targets will be applied to all new developments in England and Wales from June 2022.

The new requirements are expected to include a 31% reduction over the Target Emission Rate, new targets for Primary Energy and EPC ratings, as well as stricter fabric performance targets.

Meeting compliance will require significant changes to the way we build new homes, with the use of low carbon and renewable technologies becoming a standard practice.

SAP is also changing in Scotland, where stricter targets are expected to be enforced from 2023.

Click here to find out more

Future Homes Standard updates – The new targets

Request a quote Tel: +44 (0)8458 386 387

Linda Warner

Energy & Sustainability Specialist


Linda Warner

Energy & Sustainability Specialist

Why choose Energist?

  • Fast-track 48-hour turnaround available.
  • Energy Performance Certificates are issued the same day as your Air Leakage Test.
  • We provide solutions in a simple, easy to understand manner and are always on the lookout for the simplest, most cost-effective solution to reach compliance.
  • Value engineering comes with our SAP service as standard. If you have specific targets to meet which exceed Building Regulations, we can offer you the best solutions.

Complete solutions from Energist

  • Our technical team work closely with our Air Leakage Test Engineers to ensure joined-up thinking when your development is reaching its final stages. These tests are conducted once building work on site has finished, to confirm the predicted carbon emissions and energy efficiency.
  • Larger sites or developers who regularly build to the same specification may benefit from bespoke Thermal Bridging to improve the SAP calculation.
  • Residential dwellings will require a Water Efficiency Calculation to assess flow rates and water use of white goods.

Case study

Energist was approached by Spitfire Bespoke Homes to complete the Part L SAP calculations and Part G water efficiency reports for five new five bedroom detached houses in Surrey. Based on the initial specification, the SAP calculations were completed well within the required time frames and were comfortably meeting the required Part L Target Emission Rate. In fact, they were performing 15% better.

However, Aaron Perry from Energist’s Technical Team went the extra mile and reviewed ways of scaling back on the specification, keeping in mind that any changes couldn’t cheapen the look of the homes and couldn’t fall outside the requirements of Part L.

In total, five variations of the SAP models were presented back to Spitfire. Each one ensured compliance with the regulations while offering a cost saving to the builders. These options included a reduction in the amount of wall insulation, alternative window options and changing to a different type of ventilation system.