Firstly, SAP stands for Standard Assessment Procedure. This is the governments method for calculating and comparing the energy and environmental performance for any development. These are a requirement of Building Regulations and are required for all newly build dwellings in the UK. Since 1995 all new homes have required SAP ratings under Part L of the building regulations to comply with the planning and building control process.

The purpose of a SAP calculation is to assess how much energy a new development will consume. The calculation will vary depending on several factors. A few of which are listed below:


  • Dwelling size
  • Materials used within the construction
  • Boiler type fitted
  • The type and amount of insulation of the building fabric
  • Air pressure testing (APT) & ventilation installed
  • Sustainable energy input such as solar panels
  • Position of building for natural lighting – Daylight assessment


This process is standardised nationwide so that the comparisons and assessments are like for like on other dwellings. These calculations are then used to produce an Energy Performance Certificate (EPC). Without a ‘pass’ rating, building control will not sign off on the development, this may cause major delays in plans to sell/let a property or even build it. Unfortunately, there is not a standard set formula for achieving a ‘pass’ SAP rating. Many elements are to be considered such as predicted CO2 emissions and the solar gain.

SAP calculations are often needed for conversations and extensions too. However, slightly different regulations apply.


We have professionals at GreenBuild Consult that deal with SAP calculations day in, day out. They have a great understanding of what works best and what does not for each individual project. For all enquiries on SAP calculations, please email [email protected] or call 01656 865605. We work on projects UK wide.


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Written by Shannon Thurlby | Sales & Marketing Manager