An Energy Performance Certificate rates a home's energy efficiency from A (best) to G, using a score out of 100. It is produced by an accredited domestic energy assessor and valid for ten years. Its most useful part for a buyer is the costed list of improvements.
An Energy Performance Certificate (EPC) is a standardised assessment of how much energy a home is likely to use and what it costs to run. It gives the property a band from A to G, a score behind that band, and a costed list of recommended improvements.
Most buyers read the letter and stop. The letter is the least useful part. The rest is a public, seller-funded account of what the building is short of and roughly what putting it right costs.
This guide covers domestic certificates in England & Wales. Scotland and Northern Ireland keep separate registers under their own rules.
Who produces an EPC, and where it ends up
An EPC is produced by an accredited domestic energy assessor, who visits the property, records its construction, heating and insulation, and enters what they find into standard government software. They are not valuing the home and not surveying it — they measure it against a fixed model.
They also work only from what is visible or evidenced on the day. Insulation they cannot see and cannot be shown paperwork for is assumed to the standard of the building's age. So a certificate can under-rate a home that has had unrecorded work done.
Once lodged, it goes onto the public register, so you can look up almost any home in England & Wales without asking permission. The free EPC checker reads the register entry and explains it in buyer's terms, and how to check a property's EPC walks through the lookup.
Been to a viewing?
Put in the address and see what the data says you should offer — sold prices, time on market, seller signals.
The band is a score in disguise
The headline is a letter, but underneath it is a number out of 100:
- A 92–100
- B 81–91
- C 69–80
- D 55–68
- E 39–54
- F 21–38
- G 1–20
Read the number, because bands are wide. A home at 68 is a D one point off a C; a home at 56 is a D with the whole band ahead of it.
Band D is the most common band in England & Wales and the baseline most comparisons start from. "This one is a D" is not a finding. "This one is a D at 57, on a street of high Ds and Cs" is. EPC ratings explained covers the bands in detail.
What is actually on the certificate
Four things, and only the first is famous.
1. Current and potential ratings. What it scores now, and what it would score if the recommended work were done. The gap is the interesting figure.
2. Estimated running costs. Modelled annual costs for heating, hot water and lighting — model outputs at assumed rates, not a forecast of your bills. Every property is modelled on the same basis, but at the fuel rates current when each certificate was lodged, so figures from certificates of different vintages are not comparable in £ terms.
3. Element-by-element conditions. Walls, roof, floor, windows, heating, controls, hot water and lighting, each rated in words ("solid brick, as built, no insulation (assumed)"; "very poor"). "Assumed" is a flag to ask about, not a fact to accept.
4. Recommended improvements, with indicative costs. Specific measures, each with a typical cost range and a typical annual saving.
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When a property must have one, and how long it lasts
An EPC is legally required when a home is marketed for sale or for rent in England & Wales. The seller or landlord commissions it, and the band is meant to appear in the listing.
A certificate is valid for ten years from lodgement, and nothing obliges an owner to refresh it after work is done. So its age is information: a nine-year-old EPC describes a nine-year-old version of the property, and if the boiler has been replaced since, the register will not know.
The recommendations section: the part almost nobody reads
Scroll past the coloured chart and there is a table of recommended measures. Each row typically carries a measure, an indicative cost range and an estimated annual saving — loft insulation, floor insulation, wall insulation, a condensing boiler.
This is unusual evidence. It is not your estimate and not your surveyor's. It is a standardised certificate lodged on a public government register, which the seller commissioned and paid for. That makes it harder to dismiss as a buyer being difficult than your own estimate would be — though a seller can still decline to engage with it.
That gives you a case worth arguing, and it is worth being precise about what that is. A certificate does not entitle you to money off and does not set a discount. It gives you a documented, non-hostile way to put a number in the room: the certificate rates the walls "very poor" and puts an indicative £X–£Y on insulating them, and that work is ahead of whoever buys this house. Whether it lands, and for how much, is a negotiation — but it beats "it feels a bit cold."
What to do with an EPC before you offer
- Read the score, not just the band — where it sits inside the band, and how far the potential rating is above it.
- Hunt for "assumed", then ask whether that work was done and evidenced. An assumption you can overturn improves the property; one you cannot is a risk to price in rather than a confirmed cost — the work may have been done and never recorded.
- Check the lodgement date on the free EPC checker. An old certificate plus claimed improvements and no paperwork is a question, not a dead end.
- Start from the certificate's own indicative costings rather than your own guesses — they are specific to the property and the seller paid for them — but check the lodgement year, treat them as rough magnitudes rather than quotes, and get a written quote for the largest item before you lean on a figure.
- Get a survey anyway. An EPC will not find damp, movement or a failing roof.
Keep its limits in view. An EPC is not a valuation, and it models a standard household at assumed rates, so it tells you neither what the property is worth nor what your bills will be.
Where the rules are heading (position as of August 2026)
Regulation is where this subject attracts the most confident wrong information. Here is the position, dated.
- Privately rented homes in England & Wales must already meet band E. That minimum energy efficiency standard has been in force since April 2020. It does not cover social rented stock.
- The rental minimum rises to band C on 1 October 2030 — or its equivalent under the new metrics. This is confirmed, with one real caveat: what counts as equivalent under the new metrics is still completing its Parliamentary passage.
- Certificates themselves are changing. New-style certificates using four Home Energy Model metrics, replacing today's single score, are announced for H2 2027. Announced is weaker than confirmed; timing and detail can still move.
- There is no confirmed minimum band for selling a home. If you have read that you will need a C to sell by 2035, that came from a 2021 consultation ambition which never became policy. It is not a rule, and nobody should price a purchase as though it were.
Buying to let, a band below C is work a landlord buyer would have to budget for if the 1 October 2030 minimum lands as written — and what counts as the equivalent band under the new metrics is still being settled. The certificate has already quantified that work, which makes it dated context for a negotiation and a guarantee of nothing: the standard carries cost caps and registered exemptions, so a sub-C purchase is not an automatic bill. What a seller's EPC reveals reads the document as a signal about the sale.
General information, not financial or legal advice. Broc's scores and recommended ranges are informational guidance generated from data; outcomes vary and no result is guaranteed.
Frequently asked questions
What does EPC stand for?
Energy Performance Certificate. It rates a home's energy efficiency from A (most efficient) to G using a score out of 100, and is produced by an accredited domestic energy assessor. A home marketed for sale or rent in England & Wales needs one, with narrow exemptions such as some listed buildings.
How long is an EPC valid for?
Ten years from lodgement. It stays valid through a sale, and nothing requires an update after improvement work, so an older certificate may describe a property that has since changed.
Do I need an EPC to buy a house?
No — the obligation sits with the seller. Your job is to read it, and you can look up the certificate on the free EPC checker before booking a viewing.
Will sellers need an EPC C by 2035?
No. There is no confirmed minimum band for selling a home; that came from a 2021 consultation ambition which never became policy. The confirmed band C minimum applies to privately rented homes from 1 October 2030 — or its equivalent under the new metrics, whose details are still completing their Parliamentary passage. This is the position as of August 2026.
Broc
Broc is the badger behind trybroc.io — "broc" is Old English for badger. Where the estate agent speaks in superlatives, Broc speaks in evidence — sold comparables, days on the market, seller-pressure signals — and turns them into a number you can defend.
