EPC
/ iː piː siː /
Also known as: Energy Performance Certificate, energy rating, EPC band
Definition
An EPC (Energy Performance Certificate) rates a building's energy efficiency on a scale of A (most efficient, score 92+) to G (least efficient, score 1-20). Required when a building is built, sold, or let. Produced by an accredited domestic energy assessor from a SAP calculation for new builds, or an RdSAP assessment for existing properties. For new dwellings, Approved Document L 2021 requires a minimum EPC band B. EPCs are valid for 10 years and are publicly searchable on the national EPC register. Landlords cannot legally let properties rated F or G without an exemption.
In practice
For existing properties, an EPC is produced by a Domestic Energy Assessor (DEA) carrying out an RdSAP (Reduced data SAP) assessment - a site survey that collects information about construction type, wall insulation, loft insulation, glazing, heating system, and hot water system. The DEA uses default assumptions for data that cannot be directly observed, which can sometimes lead to inaccurate ratings (a house with solid walls where the insulation is hidden behind internal cladding may receive a poor default rating). Evidence of improvements (insulation certificates, boiler installation records) should be provided to the assessor to avoid default poor assumptions.
The EPC includes a list of recommended improvements, each showing the estimated cost, estimated saving, and the potential improvement to the EPC rating. These recommendations form the basis of an energy improvement plan for the property. The Green Deal (now largely defunct) and various government schemes (ECO4, Great British Insulation Scheme) use EPC data to target improvements. Local authority minimum energy efficiency standards (MEES) use EPC ratings to enforce minimum standards in the private rental sector.
Building Regulations
The Energy Performance of Buildings (England and Wales) Regulations 2012 (as amended) require EPCs for construction, sale, and letting of buildings. Approved Document L requires that the as-built EPC for a new dwelling is lodged on the national register before the completion certificate is issued. The Minimum Energy Efficiency Standards (MEES) Regulations 2015 prohibit letting of properties with an EPC rating below E in the private rented sector, with a cap of £3,500 on the cost of required improvements before an exemption can be claimed. The Government has consulted on raising the rental minimum to EPC C by 2030 for new tenancies, though implementation has been delayed. The Future Homes Standard (expected 2025-2026) will require new dwellings to achieve EPC A as standard.
Full Building Regulations guidanceSee also