EPC Rating Scale Explained: Understanding A to G Energy Ratings

Every Energy Performance Certificate (EPC) rates a property on a simple A to G scale, similar to the energy labels found on fridges and washing machines. A is the most energy efficient and cheapest to run; G is the least efficient and most expensive. The rating is based on a property's estimated energy costs for heating, hot water, and lighting, not on how large or valuable the property is — a small, well-insulated flat can easily outscore a large, poorly insulated house. How the Scale Works Each EPC report gives the property a score out of 100+ (the SAP score), which is then translated into a letter band: - A (92-100): Exceptional efficiency, typically only new-build or highly retrofitted homes with renewable technology such as solar panels and heat pumps. - B (81-91): Very efficient, usually modern homes built to high insulation standards. - C (69-80): Good efficiency, increasingly the standard for newer housing stock and the current government target for most homes by 2035. - D (55-68): Average efficiency, common in older or partially upgraded properties. This is the current national average rating for UK homes. - E (39-54): Below average, often older properties with limited insulation or an inefficient heating system. - F (21-38): Poor efficiency, usually old properties with solid walls, single glazing, or no loft insulation. - G (1-20): Very poor efficiency, typically older, un-insulated properties with outdated heating systems. Why the Rating Matters An EPC isn't just a formality for estate agents. It directly affects: - Running costs: A property rated A or B can cost hundreds of pounds less per year to heat and light than an equivalent F or G rated property. - Legal compliance: Under the Minimum Energy Efficiency Standards (MEES) regulations, landlords generally cannot let a residential property with an EPC rating below E. Proposed changes would raise this minimum to C for new tenancies. - Property value: Buyers and tenants increasingly factor EPC ratings into their decisions, and a poor rating can affect marketability and price. - Mortgage and grant eligibility: Some lenders offer preferential rates for highly efficient homes, and government schemes for retrofit grants are often targeted at the lowest-rated bands (E, F, and G). Improving a Rating Common, cost-effective improvements that move a property up the scale include loft and cavity wall insulation, upgrading to double or triple glazing, draught-proofing, replacing an old boiler with a more efficient model or heat pump, and adding renewable technology such as solar panels. A qualified domestic energy assessor can identify which improvements will have the biggest impact on a specific property's rating. Who Produces an EPC EPCs must be produced by an accredited Domestic Energy Assessor (DEA) or Non-Domestic Energy Assessor (NDEA), using approved software and methodology (RdSAP for most homes, SBEM for commercial and non-domestic buildings). Our DEA and NDEA training courses cover this methodology in full, preparing assessors to survey properties and produce compliant, accurate EPCs.