Who can produce a commercial EPC, and at what level

Complexity, not floor area

It is natural to assume a bigger building needs a more qualified assessor. The relevant question is actually what services the building has: simple heating and natural ventilation sits at one level, while air conditioning, mechanical ventilation and more complex systems require a higher one, and some buildings require dynamic simulation modelling rather than the simplified method.

So a small air-conditioned office can require a higher level of accreditation than a large, simply serviced warehouse. Instructing an assessor who is not accredited for your building wastes everybody’s time, because the certificate cannot be lodged.

What to check before instructing

That they are currently accredited, and with which scheme. Accreditation lapses and it is worth confirming rather than assuming.
That their level covers the services in your building. Describe the heating, cooling and ventilation when you ask, not just the floor area.
Whether the building needs simplified or dynamic modelling, and whether they do the latter.
Professional indemnity cover, particularly where the certificate will support a transaction.
Whether the fee includes the recommendation report and lodging the certificate on the register.

Independence is worth something

An assessor who also sells the improvement work has an interest in what the recommendation report says. That does not make them dishonest, and plenty of good firms do both, but it is a reason to understand who you are instructing and why.

Where a certificate is supporting a sale, a letting or a lender conversation, independence is worth more than the fee difference.

Where the certificate ends up

Lodged on the national register, where it is publicly searchable by address. That is worth knowing for two reasons: you can look up what a building already has before you commission anything, and so can a prospective tenant, buyer or lender.

If you are about to market a property, it is worth looking at what is currently on the register against it. An old certificate that understates a building you have since improved is working against you in public.

Questions we get asked

Can anyone produce a commercial EPC?

No. It has to come from an assessor accredited within a registered scheme, and accredited at a level appropriate to the building. A certificate from someone not accredited for that building cannot be lodged.

What level of assessor do I need?

It depends on the services in the building rather than its size. Simple heating and natural ventilation sits lower; air conditioning, mechanical ventilation and more complex systems require a higher level, and some buildings need dynamic simulation rather than the simplified method. Describe the services when you ask.

Should the assessor be independent of the contractor?

Where the certificate supports a sale, a letting or a lender conversation, independence is usually worth more than any fee difference, because the recommendation report carries weight. Plenty of firms legitimately do both, but it is worth knowing which you have instructed.

Where can I see a building current certificate?

Non-domestic certificates are lodged on the national register and are publicly searchable by address, so you can check what a building already has before commissioning anything, and so can a prospective tenant or buyer.

Last updated 8 October 2026.