Have you been asked for New build SAP Calculations for your development and unsure what they are and where to begin?

When it comes to SAP Calculations, the first step to identifying what you are required to do, is to identify which Part of Building Regulations your development needs to comply with.

Building Regulations Part L covers ‘The conservation of fuel and power’ and is the section that requires new build SAP calculations to be carried out and identifies the areas of compliance for each type of development.

Part L of the Building Regulations is split up into two parts;

Part L1a for New build Dwelling/s and,

Part L1b for change of use/conversion to dwelling/s and extension to an existing dwelling.

We have broken down Part L1a, how they are assessed and what the new build SAP calculations entail. (for more information on Part L1b, please see our Part L1b blog post)

Part L1a – New Dwelling/s

if you are in the planning stage or in the build process of a new build dwelling or dwellings, you will be required to have SAP Calculations carried out for each dwelling within the development. This is to determine compliance to Building Regulations standards in accordance to Part L1a,

When it comes to new build SAP calculations a number of different compliance factors are required and quite often lead to confusion on if the dwelling complies or not. This is mainly because minimum standards are set for the majority of elements within a new build, such as thermal performance of a wall, floor, roof, glazing etc. Therefore each of these individual elements within a development must meet a certain standard to comply with Building Regulations, pretty straight forward.

Where the confusion comes from is that, if all individual elements meet the minimum standard required, this does NOT mean that the whole dwelling complies to Building Regulations.

To explain this further, when SAP Calculations are carried out, the SAP assessor will ensure that all individual elements comply to the standards set out in Building Regulations Part L1a as part of the assessment, however what also must be assessed are two key areas of the build, the Dwelling Emission Rate (DER) and the Dwelling Fabric Energy Efficiency (DFEE),These two elements must also comply with Building Regulations as well as the individual elements mentioned above.

The DER & DFEE are figures created based on the dwelling as a whole rather than per element. the figures are then compared to a ‘Notional’ dwelling as exactly the same design. Therefore each dwelling has its own individual targets and is not based on targets set out in Building Regulations, Have a chat with your SAP Assessor to discuss how to ensure compliance to DER & DFEE for your dwelling.

A final note on SAP Calculations for new build dwellings would be that an Air Permeability Test will be required once the development is complete, this testing measures the air tightness of the dwelling, therefore considerations throughout the build for air tightness should be taken, Again speak to your SAP Assessor about air tightness and the air permeability target set in your calculations.

If you are looking to ensure compliance on your new build project, get in touch today, https://vision-energy.co.uk/services/sap-calculations/

David Barsted,

Managing Director

Vision Energy

vision-energy.co.uk