What a energy performance (epc) assessment covers
An EPC (Energy Performance Certificate) assessment produces the statutory rating that must be displayed when a property is sold, let, or built. The assessment surveys fabric, heating, hot water, ventilation, and lighting, runs the result through Reduced data SAP (RdSAP) for existing dwellings or full SAP for new builds, and outputs a 1-100 numeric rating mapped to bands A-G.
- Full visual survey of the property using RdSAP convention
- Wall construction, insulation level, glazing type, and area measurement
- Heating system and hot-water provision identification
- Ventilation type and lighting fitting count
- Photographic evidence (typically required from 2020 onwards)
- Lodgement of EPC to the central register
- Recommendations report for rating improvement
Typical findings
- Properties banded D-E that could reach C with cavity-wall insulation and loft top-up
- Pre-2010 properties banded F-G needing full retrofit to comply with PRS minimum standards
- EPC band misalignment with actual heating bills due to RdSAP convention assumptions
- Cavity walls assumed insulated when borescope check would show otherwise
- Heat-pump-ready properties not flagged as such due to current SAP convention bias
Typical cost: £60-£120 typical EPC assessment for a domestic property, £180-£350 commercial EPC, £80-£140 retrofit-aligned EPC with broader recommendations
When to book: Before sale or letting (statutory requirement), before applying for retrofit grant funding (ECO4 requires pre-install EPC), or to track progress after a retrofit measure.
Required qualifications for assessor: Domestic Energy Assessor (DEA) accreditation through an approved certification body (Elmhurst, Stroma, BRE, NES, ECMK), Non-Domestic Energy Assessor (NDEA) for commercial