How to read an energy performance certificate (EPC)

An energy performance certificate rates a home from A (most efficient) to G (least efficient), estimates its running costs and lists improvements that would raise the rating. It lasts 10 years, and you can look up any certificate free on GOV.UK.

Checked 16 Oct 2026

What the rating means

An accredited assessor visits the home and records its walls, roof, floors, windows, heating, hot water and lighting. Software turns those details into an energy efficiency score, and the score sets the band:

A: 92 or more
B: 81 to 91
C: 69 to 80
D: 55 to 68
E: 39 to 54
F: 21 to 38
G: 1 to 20

The score describes the building under standard assumptions about how a household heats and uses it, not how the current owners live. Two identical homes get the same rating however warm their occupants keep them, which is what makes certificates useful for comparing homes.

The certificate also breaks the home down feature by feature, rating each from very good to very poor. For a buyer this is often the most useful part: it shows at a glance whether the walls are insulated, how much loft insulation there is and what kind of heating and controls the home has.

The potential rating and the recommendations

Next to the current rating is a potential rating: the band the home could reach if all the recommended improvements were made. A large gap between the two means there is plenty of room to improve, and usually work to pay for.

The recommendations list measures in a suggested order, such as loft or wall insulation, heating controls, a new boiler or heat pump, double glazing or solar panels. Each comes with a typical cost and the rating the home would reach after it. Treat the costs as rough guides from the date of the assessment, and get quotes before you rely on them.

Some measures need permission or care in older homes. Wall insulation and new windows can be restricted in a conservation area or a listed building, so see what those designations mean for a buyer before you plan work.

Running costs and what they leave out

The certificate estimates the cost of heating, hot water and lighting for a typical household, using energy prices from when the assessment was done. It leaves out appliances and cooking. Because energy prices have moved a lot in recent years, an older certificate can show costs well below what you would pay today.

Use the figures to compare homes, not to predict your own bills. Ask the seller for a year of recent bills as well, bearing in mind that their household may use energy very differently from yours.

How long it lasts and where to find one

A certificate is valid for 10 years. A seller must arrange one before marketing the home, and the seller or agent must show it to you. If a home has had several, look at the newest; the older ones show how the home has changed. A certificate only has to be renewed when the home is next sold or let, so an expired one is common in a home that has not changed hands for years.

Go to GOV.UK’s find an energy certificate service.
Search by postcode and choose the address. Certificates are free to view and download.
Check the date, the address and the total floor area carefully: flats in the same building are easy to confuse.
If you cannot find one, ask the seller. It may be listed under a different spelling of the address.

The total floor area on the certificate is also handy for working out a price per square metre; see how sold prices and estimates work.

A certificate describes the home on the day of the assessment. If the owners have since insulated, replaced the boiler or extended, the rating may be out of date, and if the assessor could not see something, such as insulation inside a wall, they will have made assumptions based on the home’s age.

Minimum standards for renting

If you might let the home one day, the rating matters more. In England and Wales, most privately rented homes must currently be rated at least E, unless the landlord has registered a valid exemption. The government has said it wants as many privately rented homes as possible to reach band C by 2030, but the detailed rules were still being developed when this guide was written.

Check GOV.UK’s guidance for landlords for the rules in force when you buy, and ask your lender or broker whether the rating affects any mortgage offers.

Check it for a specific home

The Energy performance section of a HouseReport report shows the home’s current and potential rating, its rating history across past certificates and its running costs, and Things to check flags an expired certificate or a rating of F or G. Look up any address to see in the free preview which sections it has.

Look up any address

The free preview shows which of these checks the report answers for that home.