What is an EPC rating?

An Energy Performance Certificate rates how energy efficient your property is from A to G.

What is an EPC?

An Energy Performance Certificate (EPC) is a standardised document that rates the energy efficiency of a building. It was introduced in England and Wales in 2007 as part of EU regulations to improve energy efficiency across Europe. Even after Brexit, EPCs remain a legal requirement for most property transactions.¹

The certificate shows two ratings:

1. Current rating — what your property scores now based on its existing features (insulation, boiler, windows, etc.)
2. Potential rating — what it could achieve if you made all the recommended improvements listed on the certificate

The rating is calculated using the Standard Assessment Procedure (SAP), a government-approved methodology that estimates annual energy costs per square metre. A property that's well-insulated with an efficient heating system will score higher (closer to A) than a poorly-insulated property with an old boiler (closer to G).²

The A-G ratings scale

EPCs use a colour-coded scale from A to G, similar to the energy labels you see on appliances. Here's what each band typically means for a UK home:

A rating (92–100 SAP points)

Very energy efficient. Rare in the UK (less than 1% of homes). Usually new-build Passivhaus or heavily-retrofitted properties with triple glazing, thick insulation, and renewable heating.

B rating (81–91 SAP points)

Highly efficient. Around 5% of UK homes. Typically modern new-builds with good insulation and efficient heating (heat pump or modern condensing boiler).

C rating (69–80 SAP points)

Good energy efficiency. Around 20% of homes. Often modern homes with cavity wall insulation, loft insulation, and double glazing. Government target for all rental properties by 2030.

D rating (55–68 SAP points)

Average for the UK. Around 40% of homes. Typically 1980s–2000s homes with some insulation and a reasonably modern boiler, but room for improvement.

E rating (39–54 SAP points)

Below average. Around 20% of homes. Often older properties with solid walls, single glazing, or old boilers. Minimum legal standard for rental properties since 2020.

F rating (21–38 SAP points)

Poor energy efficiency. Around 5% of homes. Typically pre-1920s properties with no insulation and very old heating systems. Illegal to rent in England and Wales (with limited exemptions).

G rating (1–20 SAP points)

Very poor. Less than 1% of homes. Often derelict or uninhabitable properties, or those with no heating system at all.

The percentages above are based on 2024 data from the English Housing Survey.³ Your individual property's rating depends on its specific features, not just age. A Victorian terrace could be a C rating if it's been well-insulated and has a modern boiler, while a 1990s house could be an E if it hasn't been upgraded.

When you need an EPC

You must have a valid EPC when you:¹

• Sell a property — the EPC must be available to prospective buyers from the point the property is marketed
• Rent out a property — the EPC must be given to prospective tenants before they move in
• Construct a new building — the builder must provide an EPC to the owner when the building is completed

When you don't need an EPC

You do not need an EPC if:

• You own your home and are not selling or renting it
• The building is a listed building or in a conservation area (exemptions apply in some cases)
• The building is due to be demolished and has a valid demolition notice
• The building is used primarily for worship or religious activities
• It's a temporary building with a planned use of less than 2 years

However, even if you're not legally required to have an EPC, getting one can be useful. It helps you understand where your property loses energy and prioritise improvements. Many grants and funding schemes (like the Boiler Upgrade Scheme) require you to provide your current EPC rating when you apply.

How long does an EPC last?

An EPC is valid for 10 years from the date of assessment.¹ You can use the same certificate for multiple sales or tenancies within that 10-year period. You don't need to get a new one each time you rent the property to a new tenant, as long as the existing EPC is still valid.

However, if you make significant improvements to the property (like installing a new boiler, adding insulation, or replacing windows), it's worth getting a new assessment. A better rating can make the property more attractive to buyers or tenants, and it might move you above the minimum E rating threshold if you were previously below it.

What assessors check

A qualified Domestic Energy Assessor visits the property and measures or records:²

• Property dimensions — floor area, room sizes, ceiling heights
• Walls — construction type (solid, cavity, timber-frame), thickness, insulation
• Roof — construction, insulation thickness in loft or flat roof
• Floors — suspended or solid, insulated or not
• Windows and doors — glazing type (single, double, triple), frame material, percentage of wall area that's glazed
• Heating system — boiler type and age, fuel type (gas, oil, electric), efficiency rating, controls (thermostat, TRVs, smart controls)
• Hot water — cylinder type, insulation, whether it's on a timer
• Lighting — percentage of low-energy bulbs
• Renewable energy — solar panels, heat pump, wind turbine

The assessor doesn't do an invasive survey. They won't lift carpets or drill into walls to check cavity insulation. If they can't see evidence of insulation (like visible loft insulation from the hatch), they assume there's none. This means some properties may be rated lower than they actually are if improvements aren't visible.

The assessment usually takes 30 to 60 minutes for a typical house, slightly less for a flat. The assessor enters all the data into government-approved software, which calculates the SAP score and generates the certificate. You should receive the certificate within a few days, and it's automatically uploaded to the national EPC register.

Where to find your EPC

All EPCs issued in England, Wales, and Northern Ireland are stored in a free public register. You can look up any property's EPC by postcode at:

find-energy-certificate.service.gov.uk

Scotland has a separate register at scottishepcs.gov.uk.⁴

If you've lost your paper copy of an EPC, you can download it from the register for free. The register also shows recommendations for improvements and the estimated cost and savings for each recommendation (though these are rough estimates and may not reflect current prices).