How to choose a commercial EPC assessor
Any accredited assessor can lodge a certificate. The difference between a good instruction and a bad one shows up later — in audit failures, defaulted ratings that cost you a band, and certificates that collapse under a buyer's due diligence. Run these seven checks first. They apply to us as much as to anyone else.
1. Verify accreditation, not just claims
Every legitimate non-domestic energy assessor belongs to a government-approved accreditation scheme — Elmhurst Energy, Stroma, Quidos, Sterling and ECMK are the names you will meet most often. Ask for the assessor's name and accreditation number, then check it on the scheme's public register. Thirty seconds of checking filters out the brokers who sell your job to whoever is cheapest that week without telling you who turns up.
2. Match the level to the building
Assessors qualify at Level 3, 4 or 5, and a certificate produced below the building's required level is invalid. Air conditioning anywhere in the building generally means Level 4 minimum. A competent firm asks about your HVAC before quoting; if a quote arrives without anyone asking what heats and cools the building, that is the tell. The level definitions are on our commercial EPC guide.
3. Ask how they handle evidence and defaults
The single best probing question: "What happens if you can't evidence the wall construction or the boiler efficiency?" The right answer mentions SBEM defaults, explains they reduce the rating, and includes a request for your documentation up front. An assessor who plans the evidence with you before the visit consistently produces better — and more defensible — ratings than one who treats the survey as a walk-through. What to gather is listed on the process page.
4. Check lodgement history for your building type
Commercial stock is heterogeneous. An assessor who lodges office EPCs weekly may rarely touch a hotel, a cold store or a church hall, each of which has its own zoning and activity quirks in SBEM. Ask how many buildings like yours they have certified in the past year. Regional firms often hold the deepest knowledge of their local stock — Leicester assessors Energy Concerns, for example, built their lodgement history on the East Midlands' factory and warehouse buildings. For unusual stock, that answer matters more than price.
5. Confirm professional indemnity insurance
Accreditation schemes require PI cover, but limits vary. If a defective certificate delays a sale or triggers a MEES penalty, PI insurance is what stands behind the assessment. For high-value transactions, ask for the certificate of insurance and check the limit is proportionate to the deal — £1 million is typical; some portfolio work justifies more.
6. Read the quote for scope, not just the number
A complete quote states the assessment level, what is included (survey, modelling, lodgement fees, the recommendation report), turnaround, and the price as fixed rather than indicative. Watch for two patterns: "from" pricing that doubles once the assessor sees the building, and quotes that exclude register lodgement fees as a footnote. Typical fair pricing by building type is on the cost page.
7. Probe the turnaround promise
"Certificate in 48 hours" usually means 48 hours from survey, not from instruction — and the survey slot is where lead time actually lives. If a transaction is waiting, get both dates in writing: survey date and lodgement date. Reputable firms hit two to four working days from survey for SBEM buildings without charging panic rates.
A note on price as a signal
EPC assessment is a competitive, fairly transparent market, so quotes for the same building cluster. An outlier 40% below the cluster is funding itself somewhere — usually survey time, which becomes defaults, which becomes your problem if the building sits anywhere near the MEES boundary described in the MEES guide. Cheap is fine for a simple Level 3 unit with good documents. It is a false economy for a complex building with a lease event attached.