A Commercial EPC (Energy Performance Certificate) rates the energy efficiency of a non-domestic building on a scale from A to G, and it’s a legal requirement whenever that building is constructed, sold or let. Landlords who let without one risk fines calculated as a percentage of the property’s rateable value – so before any of that becomes relevant, it’s worth understanding exactly what the certificate covers, who has to produce it and where the exemptions genuinely apply.
In this blog you’ll learn:
- What happens if you don’t have one when you need it
- What a Commercial EPC actually measures, and how it differs from a domestic one
- When you’re legally required to have one
- How the rating is calculated
- Which buildings are exempt
What is a Commercial EPC?
A Commercial EPC certifies the energy efficiency of a non-domestic building, rating it from A (most efficient) to G (least efficient). Unlike a domestic EPC, which scores a property on running cost, a commercial assessment is based on carbon emissions – a distinction that matters, because it changes how certain building types and fuel sources are scored. An approved Non-Domestic Energy Assessor (NDEA) has to produce the certificate; it isn’t something a general surveyor or letting agent can issue.
Every EPC also comes with a recommendation report, setting out specific measures that would improve the building’s rating.
When Do You Need a Commercial EPC?
You need a valid Commercial EPC whenever:
- The premises are rented out or sold
- A building under construction is finished
- There are changes to the number of parts used for separate occupation, and those changes involve providing or extending fixed heating, air conditioning or mechanical ventilation systems
This has been a legal requirement since April 2008, and the certificate needs to be available before the building goes to market – not produced retrospectively once a buyer or tenant is interested.
If your building is over 500m², frequently visited by the public and already has an EPC from a sale, rental or construction assessment, it must also be displayed on-site.
How is a Commercial EPC Calculated?
The rating is generated using SBEM (Simplified Building Energy Model) software, which models the building’s energy performance based on:
- Construction type – walls, roof, floors and glazing
- Heating, cooling, ventilation and hot water systems
- Lighting
- How different zones of the building are used
Where no air tightness test result exists, SBEM applies a default air permeability assumption instead – and that default varies by the building’s age and size, not a single flat figure:
- Built to 2002 Building Regulations or later, floor area over 500 m²: 10 m³/(h·m²) @ 50 Pa
- Built to 2002 Building Regulations or later, floor area 500 m² or under: 15 m³/(h·m²) @ 50 Pa
- Built to 1995 Building Regulations: 15 m³/(h·m²) @ 50 Pa
- Pre-1995 buildings: 25 m³/(h·m²) @ 50 Pa
- Pre-1995 buildings with evidence of severe high permeability: 35 m³/(h·m²) @ 50 Pa, where applicable
Because these defaults sit well above what most buildings actually achieve, a real air test can move a rating considerably – as it did for two Bristol warehouses relying on the pre-1995 default of 25:
Commercial EPC Ratings and MEES
Ratings run from A (0–25) down to G, with a net-zero-carbon building scoring 0. For most commercial buildings being sold or let, the minimum acceptable rating under the Minimum Energy Efficiency Standards (MEES) is currently E.
For the fuller picture on where MEES is heading, see our MEES 2030 guide.
What Happens If You Don’t Have One?
You can be fined between £500 and £5,000, based on the building’s rateable value, for failing to make an EPC available to a prospective buyer or tenant. If you receive a penalty charge notice, you can request a review, and – if that review doesn’t resolve it – appeal to the county court (or sheriff court in Scotland) within 28 days of the confirmed penalty.
Are Any Buildings Exempt?
A small number of non-domestic buildings don’t need an EPC. In England and Wales, that currently includes:
- Places of worship
- Some listed buildings (check with your local authority conservation officer – whether the exemption applies depends on the specific works)
- Industrial sites, workshops and non-residential agricultural buildings with low energy demand
- Temporary buildings in use for under two years
- Stand-alone buildings under 50m² of total useful floor space
- Buildings due to be demolished, where the relevant planning and conservation consents are already in place
What’s Next?
Whether you’re marketing a building for sale, renewing a lease, or just confirming where you stand under MEES, getting the right rating starts with the right assessment.
We carry out Commercial EPC assessments, including the air tightness testing that can lift a rating clear of SBEM’s default assumptions.