Energy Performance Certificate (EPC)
A standardised rating of a building's calculated energy performance, typically on an A–G scale, required in the EU and UK when buildings are sold or rented.
An Energy Performance Certificate rates a building's modelled energy use under standard occupancy and climate, not its actual metered consumption. EPCs were introduced across the EU by the Energy Performance of Buildings Directive (EPBD, 2002/91/EC) and must be shown in property advertisements. The 2024 recast EPBD requires harmonised A–G classes, with class A reserved for zero-emission buildings.
Primary energy = Σ final energy by carrier x primary energy factor
UK SAP: rating 1–100+ from modelled energy cost per m², mapped to bands A (92+) to G (1–20)
Inputs include floor area, wall and roof U-values, glazing, airtightness assumptions, heating system efficiency, hot water, lighting and on-site renewables. National methods differ: the UK uses SAP/RdSAP, Germany issues demand-based (Bedarfsausweis) or consumption-based (Verbrauchsausweis) certificates, and France's DPE combines primary energy with CO2 emissions.
EPCs increasingly carry legal consequences. France bans new leases of G-rated homes from 2025 and F-rated from 2028; the Netherlands requires offices to hold at least label C since 2023; England requires a minimum E for private lets. Critics note that assessments are cheap, quickly done and can diverge substantially from real consumption, especially in older homes where occupants under-heat. A passive house typically rates A.
Related terms
All terms →- U-value
The thermal transmittance of a building element: heat flow in watts per square metre per kelvin of temperature difference (W/m²K). Lower is better.
- Passive house (Passivhaus)
A rigorous building performance standard, developed in Germany in the 1990s, achieving very low heating demand through insulation, airtightness and heat-recovery ventilation.
- Primary energy
Energy in its raw natural form before conversion, such as crude oil, coal, natural gas, uranium, biomass, and the electricity or heat from renewables.
- Heat pump
A device that uses a refrigeration cycle to move heat from a cooler source (air, ground, water) to a warmer sink, delivering 2–5 units of heat per unit of electricity.
- Thermal bridge
A localised area of a building envelope with significantly higher heat flow than its surroundings, caused by geometry or more conductive materials.