The Standard Assessment Procedure (SAP) Calculations

The Standard Assessment Procedure (SAP) is the Government’s methodology used to assess and compare the energy and environmental performance of dwellings.

Understanding the Standard Assessment Procedure Calculations

SAP 10 put in place from the 15th of June 2022 is the latest revision of the SAP document. It is used to demonstrate Part L compliance of the Building Regulations England & Wales for new dwellings. SAP assessments may also be required for extensions or conversions, and we can advise on these when needed.

The assessment involves using accredited software to calculate the property’s energy performance. This is done by a qualified and accredited Domestic on Construction Energy Assessor (OCDEA) who will require detailed information about the build including specification and floor plans etc.


What are the Part L Regulations?

The Part L Building Regulations control the guidelines for construction projects that are new, or are because of a change of use of a building in England.

These regulations set the standard for minimum energy performance and emissions of new and existing buildings.

For new non-domestic buildings you will need a Simplified Building Energy Model (SBEM)


Design Stage SAP Calculations

Our in-house Energy Assessors will support you through this process and will always offer best advice relevant to your build. We recommend you conduct the SAP assessments at design stage to ensure compliance with Part L regulations early on. Starting your SAP assessments too late could mean that your project is not to standards and remedial work will be necessary.

It is a Building Regulation requirement to submit a Design Stage SAP assessment to Building Control at least 1 day before work commences on site.


Top Tips for SAP Calculations

At Cook Brown we are experts in Standard Assessment Procedure, and we recommend our clients do the following:

  • Beat the Minimum U Value – You should aim to beat the minimum U Value threshold; this will make your project more costs effective and efficient in the long term.
  • Avoid Thermal Bridges –Thermal bridging can occur through the junctions between different building elements. Avoiding these will allows us to use more than default figures.
    Learn more about Thermal Bridges >
  • Invest in good windows and doors – Windows and doors are where most buildings lose most of their heat. Ensuring that these are as efficient as possible will prevent wasted energy.
  • Use Low Energy Lighting – We advise using LEDs (Light Emitting Diodes) throughout as they are more efficient and longer lasting than conventional filament bulbs.
  • Air Testing – Buildings are most efficient when there are as few as leaks as possible as this prevents heat escaping in cold months.
  • Installing Renewable Technology – If you have the facility to invest in technology such as solar panels to produce electricity or to heat water, you are likely to see a better score in your calculations.


SAP Calculations with Cook Brown

We offer a fully supportive services from Design Stage and As Built SAP calculations to Landmark Registration and Energy Performance Certificates.

Whether you have a new build, extension, or conversion get in touch with our technical energy assessors on 01275 846995 or email us on