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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 in England are changing.

Proposals include reducing the Target Emission Rate by up to 31%, introducing a new energy target and setting lower U-Value thresholds.

As part of the Building Regulations in England, Wales and Scotland, every new-build dwelling is required to meet compliance against regularly updated energy efficiency standards. For a residential building, a Standard Assessment Procedure (SAP) Calculation is used to show this compliance.

Our SAP specialists review your building plans and the proposed specification and compare your building’s expected carbon emissions against a target. The data produced from the calculation is then used to produce an Energy Performance Certificate (EPC), which is required to sell or rent a dwelling.

Due to the nature of this calculation, the ideal time to complete a SAP is once you’ve received planning approval but before you start on site. This gives our specialists the best opportunity to offer solutions that will ensure compliance should your proposed specification fall short of the carbon emission target.

We work closely with local authorities to understand their requirements and have over 10 years’ experience in producing accurate calculations that authorities can trust. We look at the bigger picture when producing your SAP, and if we think you are over-committing in specific areas, we’ll notify you and identify where you can save money.

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

Linda Warner

Energy And Sustainability Specialist


Linda Warner

Energy And 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.

  • “Connie and the team always provide a technically competent solution to the issues in hand.”

    Robert Taylor, Spitfire Bespoke Homes