An Energy Performance Certificate, or EPC, summarises a property's modelled energy performance and suggests improvements. It can help you understand a home, but its figures are estimates rather than a forecast of your own bills.
Use the certificate to prepare questions about the property and any work you are considering.
Find the correct certificate first
Search the official government register by postcode, street and town, or certificate number. Match the full address, including any flat number, and check the expiry date.
An EPC is generally valid for ten years, unless a newer certificate replaces it. You can download an existing certificate for free. Do not order a replacement simply because you cannot find a paper copy. See GOV.UK's EPC guidance.
What does the rating mean?
The energy-efficiency scale runs from A to G, with A the most efficient. A domestic EPC uses a standard calculation based on the property and its energy-related features.
The calculation uses standard occupancy assumptions. It is not based on the number of people currently living there or their personal heating routine. This lets the certificate describe the building on a common basis, but limits what it can tell you about a particular household.
Read the government's guide to domestic EPCs for how the certificate is used.
Why are the estimated costs different from my bills?
Your bills reflect your tariff, weather, heating choices and household energy use. The EPC uses assumptions to calculate estimates, so a difference between those figures and your bills does not, on its own, establish an error.
Check what each figure describes before comparing it with a bill. Energy Saving Trust's EPC guide explains the rating and the information included.
For example, two households living in the same property at different times may heat different rooms or keep different temperatures. The certificate is not a promise that both households will spend the estimated amount.
How should I use the recommendations?
Treat each recommendation as an option to investigate. Indicative installation costs are not a contractor's quotation, and estimated savings are not guaranteed.
Make a shortlist connected to the problem you want to solve. For each item, ask:
- Does it address the cold room, draught or energy use that concerns me?
- What needs checking in this building before the work can be specified?
- What preparation, ventilation changes and finishing work would be included?
- What assumptions sit behind the expected savings?
An EPC recommendation does not select every material or detail the installation design. For insulation, use our guide to comparing proposals before choosing a product.
Does a low rating explain every problem in the home?
No. A rating is a summary of modelled energy performance. Do not use the letter alone to diagnose a cold room or decide which product to buy.
Take the certificate to an adviser and describe the actual concern. A useful request is: "Please explain which recommendations relate to this problem and what you need to check before proposing work."
Our guide to energy-efficient homes explains how comfort, heating demand and bill savings can differ.
What if improvements have been made since the EPC?
The existing certificate does not update automatically after work. If you need a certificate reflecting changes, discuss a new assessment. Keep relevant installation records so you can ask what evidence may be useful.
Improvements do not guarantee a particular band. If your aim is a target rating, explain that aim before commissioning work and ask what the advice is based on.
For a new EPC in Greater London, see prices and booking details or check your property's price. Appointment availability is confirmed with you after the request.
Sources checked: 22 October 2026.