SAP 10 –  Finally electric heating is starting to be considered as efficient as gas

26/02/2019 by Wandle Electrical Services

EPC image

This blog but it’s well worth a read if you are a homeowner or landlord.   Especially if you need to understand changes to how EPC’s are assessed in regard to types of heating: The EPC (energy performance certificate) is tested against the SAP (standard Assessment procedure).  The BEIS and BRE have finally published SAP 10 – the eagerly awaited update to SAP 2012.

SAP Calculations are used to demonstrate the energy performance of dwellings in the UK and are a key part of building regulations compliance. The SAP document defines exactly how the EPC assessment works and is updated every 4 years.

Here is a summary of the major changes and what they might mean to you:

Electric CO2 emissions reduce significantly

The changes to the electricity related carbon emissions may be the most significant factor – reducing from 0.519 kgCO2/kWh to 0.233 kgCO2/kWh, now only slightly higher than mains gas (0.210).

SAP 2012 assumes that any electricity used produces 2.4 times the carbon emissions of mains gas – this is because it uses an outdated carbon factor which is not reflective of the current energy mix of the grid. The ‘greening of the grid’ means there is now much more renewable and clean energy online with much less coal being burned.

Targets within SAP are currently based on mains gas, so this heavily penalises electric use, and certainly any new builds with all electric heating are incredibly difficult to pass without additional renewable technologies being installed.

We are pleased to see a much more representative carbon factor being applied, which will certainly mean electric heating is treated more fairly when it comes to Energy performance certificate.

As the ‘Greening of the Grid’ continues we are likely to see further reductions in the carbon factor used for electricity.  Some are already reporting that the factor in SAP 10 is outdated and electricity is even closer to gas.

If you have any further questions about electric heating’s performance during and EPC assessment, then please email me at Anthony@wandle-elec.co.uk or talk to your local EPC assessor.  We fit efficient electric heating systems in the Croydon, Sutton, Wallington and Carshalton areas.

Based in Wallington

Wandle Electrical Services specialise in domestic installations and the provision of a range of services directly to Homeowners, Letting Agents and Landlords.




  • About
  • Wandle Electrical Services specialise in domestic installations and the provision of a range of services directly to Homeowners, Letting Agents and Landlords. anthony@wandle-elec.co.uk.
  • 27 Belmont Road
  • Wallington
  • UK
  • SM6 8TE
  • 020 8914 8297