What is an EPC and when does your home need one?

If you are selling your home, letting it out or have just had one built, you need an Energy Performance Certificate, usually called an EPC. It rates how energy efficient the property is from A (most efficient) to G (least efficient), lasts 10 years, and has to be in place before the property goes on the market.

This guide explains what an EPC shows, when the law says you need one, what happens on the day of the assessment, and the rule changes landlords should know about. We carry out domestic EPC assessments ourselves, so it also covers what to have ready when the assessor visits.

What an EPC shows

An EPC is a short report on how much energy a home is likely to use and how it could use less. It includes:

• A current rating and a potential rating. The current rating is how the home performs today. The potential rating is what it could reach if the recommended improvements were made.

• A breakdown of the main parts of the home. Walls, roof, floor, windows, heating, hot water and lighting are each given a star rating, so you can see where the weak spots are.

• Recommendations. A list of improvements in order of importance, each with a rough installation cost, the likely saving on bills and how much it would lift the rating.

The figures come from a standard calculation, not from your actual bills. Two identical houses get the same rating however warm each household keeps its home, which is what lets buyers and tenants compare one property with another fairly.

When you need an EPC

In England and Wales you must have a valid EPC when you sell, rent out or build a home. If you are selling, you need to order it before the property is marketed, so buyers can see the rating from the start. Landlords must give a copy to new tenants.

You do not need one simply because you live in your home, or to have work done on it. If you sell or let without a valid EPC, you can be given a fixed penalty of £200.

How long an EPC lasts and how to check yours

An EPC is valid for 10 years. You can look up any home in England, Wales or Northern Ireland on the government's EPC register using the postcode, and download the certificate for free.

If your certificate is still in date, you can use it again when you sell or let. It is worth checking it first, though. If you have since fitted a new boiler, added insulation or replaced the windows, an old certificate will not reflect that, and a new assessment could give you a better rating to show buyers or tenants.

What happens at an EPC assessment

Only an accredited assessor can produce an EPC. The visit is a non-invasive survey: nothing is lifted, drilled or opened up. The assessor looks at and records:

• the age and type of the property, and how the walls, roof and floors are built

• loft, wall and floor insulation where it can be seen

• the windows and glazing

• the boiler or other heating system, the hot water and the heating controls (the thermostat, timer and the valves on the radiators)

• fixed lighting

Most homes are assessed in one appointment. The information is then entered into approved software, and the certificate is produced and lodged on the national register.

It helps to have paperwork ready. Where the assessor cannot see something, such as insulation inside a cavity wall, the software falls back on assumptions based on the age of the house, and those assumptions are often cautious. Guarantees for cavity wall or loft insulation, certificates for replacement windows, and paperwork for a newer boiler, heat pump or solar panels all let the assessor record what is really there.

What landlords need to know now and by 2030

Since April 2020, landlords in England and Wales cannot let a home rated F or G unless they have registered a valid exemption. Landlords are not currently expected to spend more than £3,500 to reach band E, and fines for letting a home that falls short can reach £5,000 per property.

The bar is set to rise. In January 2026 the government confirmed that it plans to require privately rented homes to reach the equivalent of EPC band C by 1 October 2030, with landlords expected to spend up to £10,000 per property. These changes still need Parliament's approval, so the detail may shift, but if you let a home rated D or below, it is worth starting to plan now.

How EPC ratings are changing

The government also plans to change the certificate itself. Instead of one A to G rating, new EPCs will show four separate measures: how well the building holds heat, the heating system, energy costs, and how ready the home is for smart energy use, such as charging at cheaper times of day. The launch has been put back to the second half of 2027. Until then, EPCs are produced in the current format, and a certificate issued now stays valid for its full 10 years.

Improving your rating after the assessment

The recommendations on your EPC are a good place to start. Common ones include more loft insulation, cavity wall insulation, better heating controls and low-energy lighting. Bigger steps include replacing an old, inefficient boiler or moving to a heat pump.

Because we are heating and electrical engineers as well as carrying out EPCs, we can talk you through which recommendations make sense for your home. Where the work is ours to do, such as a new boiler or an air source heat pump, we can carry it out too. Insulation is specialist work, so for that we would point you to an insulation installer.

If you need an EPC to sell or let a home, or want to know where your property stands before the rules change, REGH Ltd can carry out the assessment. You can find out more and book on our domestic EPC page.