Find the right energy assessor

The UK splits energy assessment across several distinct accreditations, and certificates are only valid when produced by the matching one. Two minutes here saves a wasted fee — start with the property, then the purpose.

Homes: the Domestic Energy Assessor (DEA)

If the property is a dwelling — house, flat, bungalow, HMO let as a single household — you need a DEA. They survey using RdSAP (Reduced Data SAP), the government's methodology for existing homes, thoroughly modernised by the RdSAP 10 update. The survey takes roughly 45 minutes to an hour and a half under the current methodology, and the certificate lasts ten years.

Two domestic edge cases catch people out. New-build homes need an On-Construction assessment using full SAP, done by an OCDEA — a separate qualification usually arranged by the developer, not the buyer. And homes undergoing grant-funded efficiency work need a retrofit assessment rather than a standard EPC (next section). If you are simply selling or letting an existing home, a DEA is the answer, and the cost guide tells you what to pay.

Commercial buildings: non-domestic assessors, Levels 3–5

Commercial property uses an entirely separate qualification ladder, graded by building complexity:

• Level 3 — simple buildings: naturally ventilated shops, small offices, basic industrial units with straightforward heating.
• Level 4 — anything with air conditioning or complex services, which in practice means most modern offices and larger retail.
• Level 5 — buildings needing dynamic simulation: large atria, sophisticated ventilation, automatic facade controls.

The level is a legal floor, not a preference — a Level 3 assessor's certificate on a Level 4 building is invalid. Our commercial assessment page covers the detail, and genuinely complex instructions are best routed to dedicated commercial EPC specialists who handle Level 4 and 5 work daily.

Grant-funded upgrades: the retrofit assessor

Publicly funded efficiency work — ECO4, the Boiler Upgrade Scheme pathway, local authority schemes — generally runs under PAS 2035, which requires a retrofit assessment before measures are installed. A retrofit assessor surveys the whole dwelling (condition, ventilation, heritage constraints) so measures are designed rather than bolted on. Many retrofit assessors are DEAs with the additional qualification, but the assessment itself is a different, longer exercise than an EPC — typically two to three hours on site.

Commercial cooling: the TM44 inspector

Buildings with more than 12 kW of total air-conditioning output need a statutory TM44 inspection every five years — aggregated across all units, which is why ten small splits count. This is yet another separate accreditation, and the duty is the most-missed in UK commercial property. If you control a building with any meaningful cooling, it is worth thirty seconds of adding up nameplate ratings.

Verifying any assessor in under a minute

Every accredited assessor in England, Wales and Northern Ireland appears on the official register — searchable through the government's energy certificate service and the accreditation schemes' own registers (Elmhurst, Stroma, Quidos, Sterling, ECMK). Scotland maintains its own register with equivalent checks. Verify three things: the name matches the person attending, the accreditation is current, and the qualification covers your assessment type.

That check is the whole defence against the market's one real scam: unaccredited "assessors" producing certificates that never lodge. If a certificate is not on the national register, it does not exist legally — no register entry, no EPC.

Or let the matching do it

This site exists because the splits above are genuinely confusing and the cost of guessing wrong is a wasted fee and a lost week. Tell us the property and the purpose via the booking form; we confirm the assessment type, verify the assessor against the register, and return a fixed price within one working day. What happens on the day itself is covered in the assessment walkthrough, and the preparation guide covers the documents worth digging out first.