Non-Domestic EPC: What It Is and When You Need One

If a solicitor, a landlord, building control or the gov.uk website has told you that you need a non-domestic EPC, here’s the plain answer first: a non-domestic EPC is a commercial EPC. “Non-domestic” is the official term used in the legislation and on the government register for the Energy Performance Certificate that covers any building — or part of a building — that isn’t someone’s home. Shops, offices, warehouses, restaurants, surgeries, salons: all non-domestic.

The two names cause real confusion, and some of it costs money — owners searching the wrong half of the EPC register, or booking a domestic assessor who legally can’t certify their shop. This page clears the terminology up properly: what counts as non-domestic, how the certificate differs from the one on a house, what happens in the assessment, and when the law requires one. We provide non-domestic EPCs across the country — accredited assessors, fixed fee, UK-wide.

Request a fixed-fee quote — tell us the property type, rough floor area and postcode, and we’ll confirm the price up front.

What is a non-domestic EPC?

A non-domestic EPC is the official energy-efficiency certificate for a commercial building. It rates the building’s energy performance on a scale from A+ to G — based on the carbon emissions the building is modelled to produce — and comes with a recommendation report listing improvements that would raise the rating. The certificate is produced by an accredited assessor, lodged on the government’s non-domestic EPC register, and remains valid for 10 years. In everyday speech it’s called a commercial EPC; in the regulations and on gov.uk it’s a non-domestic EPC. Same certificate, two names.

Non-domestic vs domestic EPC: the real differences

The two certificates look similar but are produced under entirely different systems — which is why a domestic assessor can’t do your shop, and vice versa:

Different calculation method. A non-domestic EPC is produced using SBEM (the Simplified Building Energy Model — the government’s standard calculation for commercial buildings), or full dynamic simulation software for the most complex buildings. A domestic EPC uses RdSAP for existing homes and full SAP for new ones — a method built around how households use energy.

Different assessors. Non-domestic EPCs need a non-domestic energy assessor, accredited at Level 3, 4 or 5 to match the building’s complexity — Level 3 for simple naturally ventilated units, Level 4 where there’s significant air-conditioning or complex services, Level 5 for buildings needing dynamic simulation. Domestic assessors hold a separate qualification and cannot lodge commercial certificates.

Different rating basis. The non-domestic scale runs A+ to G and reflects CO₂ emissions per square metre; the domestic scale runs A to G and is driven largely by modelled energy costs. The same fabric can therefore score differently in each system — the ratings aren’t comparable across the two.

Different register category. Both certificate types sit on the gov.uk “Find an energy certificate” service, but in separate lists. Searching the domestic list for a commercial unit finds nothing — a common false alarm.

What counts as a non-domestic building?

Broadly: any building, or self-contained part of a building, that isn’t used as a private dwelling. That covers offices, shops and retail units, warehouses and industrial units, restaurants, cafés and pubs, hotels and guesthouses, surgeries and clinics, salons, gyms, showrooms, nurseries and schools, village halls and places of worship (some of which qualify for exemptions). The label follows the building’s use, not its ownership or appearance — a Victorian terraced house converted into offices needs a non-domestic EPC, and a purpose-built flat above it needs a domestic one. For a type-by-type breakdown of how different premises are assessed, see our EPC for business premises guide.

Mixed-use buildings: the shop with a flat above

This is the question we’re asked most, and the principle is simple once stated: each self-contained part of the building gets its own EPC, matched to its use. So for the classic high-street building:

The shop needs a non-domestic EPC.

The flat above, if it’s self-contained — its own entrance (even from a shared hallway), its own facilities, capable of being sold or let separately — needs its own domestic EPC.

If the “flat” is not self-contained — say, staff rooms upstairs reached only through the shop, with no independent access — it’s normally treated as part of the commercial premises and covered by the one non-domestic EPC.

The certificates are triggered independently: selling the whole building typically means both are needed, while letting only the flat triggers only the domestic one. If you’re unsure which side of the line your building falls, send us the layout — it’s a two-minute answer and it’s free.

When is a non-domestic EPC required?

The triggers are set by law, and they’re the same whether you call the certificate commercial or non-domestic. You need a valid one when the building is sold, when it’s let to a new tenant, and when it’s newly built (or converted in a way that changes its heating or use). On top of that sits MEES — the Minimum Energy Efficiency Standards — which currently make it unlawful to let most commercial property rated below E, including under leases that are already running. The full picture, including the marketing rules and penalty regime, is on our commercial EPC requirements page; what the E threshold means in practice is covered under the minimum EPC rating for commercial property; and the proposed tightening of the rules over the next decade is on our commercial EPC regulations 2030 page. A small number of buildings — some listed buildings, temporary structures, certain low-energy industrial sites and places of worship — may be exempt.

What does a non-domestic EPC assessment involve?

You send the basics. Property type, rough floor area, postcode, and floor plans if you have them (they speed things up but aren’t essential). We confirm the assessment level your building needs and a fixed fee before any work starts.

Site survey. The assessor visits and records what the calculation needs: the building’s construction and insulation, zones and their uses, heating, hot water, lighting, and any ventilation or air-conditioning.

The SBEM calculation. The survey data is modelled in approved software to produce the rating — an honest model of what’s actually installed, because an inaccurate EPC helps nobody and can be challenged.

Lodgement and delivery. The certificate and its recommendation report are lodged on the official register — lodgement is included, never a bolt-on — and you receive the documents and the certificate reference number for your solicitor or agent.

Straightforward premises are usually surveyed, modelled and lodged within a few working days of the visit. If the property already holds a certificate and you only need to know what it says, don’t book anything yet — the register search is free, and an in-date rating of E or better may mean a new assessment isn’t needed until the certificate expires or the building changes.

How much does a non-domestic EPC cost?

Exactly what a commercial EPC costs — it’s the same certificate, so beware anyone quoting them as different products. The fee tracks the building’s size and complexity: a small naturally ventilated unit sits at the lowest end, while larger or air-conditioned buildings need a higher-level assessment and cost more. We don’t publish a one-size-fits-all price because there isn’t one; we quote a fixed fee up front from your property details, with the survey, calculation, lodgement and recommendation report all included. Our commercial EPC cost guide explains the price drivers in full.

Request a fixed-fee quote — property type, floor area, postcode in; fixed price back, usually the same day.