Energy Performance Certificate (EPC)

A document rating a property's energy efficiency from A (best) to G (worst), legally required for sales, lets and most retrofit grant applications.

An Energy Performance Certificate (EPC) rates your property's energy efficiency on a scale of A (92+) to G (under 21). It is generated by an accredited Domestic Energy Assessor (DEA) using the SAP or RdSAP methodology, and is valid for 10 years.

You need an EPC to sell or let a property, to apply for the Boiler Upgrade Scheme, ECO4 or Warm Homes Local Grant, and to comply with MEES rules. As of 2026, all rented properties must have at least an EPC E, with the proposed EPC C 2028 rule tightening this further.

Heat pumps now score better on EPCs than they used to. The 2024 SAP 10.2 update reduced the carbon factor for grid electricity, which means installing an ASHP often raises a Cornish property's EPC by 1-2 bands. Combine with solar PV and you can comfortably hit EPC B or A. Find an assessor via the gov.uk register or ask CCS for a recommendation.