An Energy Performance Certificate rates how energy-efficient a building is, from A at the best to G at the worst, and lists what would improve it. Nearly every property sold or let in England and Wales needs a valid one, and it is a public document: anyone can look yours up by postcode, free, without telling you.
The short version
A score out of 100 turned into a letter band. A second, higher band showing what the listed improvements would reach. An estimate of running costs. A table of what the building is made of. A list of measures with indicative costs. Valid ten years from the day it is lodged.
EPC, EPC certificate, energy certificate
All the same document. The formal name is Energy Performance Certificate, so "EPC certificate" repeats itself, but it is what most people search for and estate agents use it too. If someone asks for an energy certificate, an energy rating, an energy performance survey or a SAP rating for an existing home, they almost always mean this.
It is not a survey. It says nothing about condition, defects, damp or value. A buyer wanting to know whether a house is sound needs a RICS Level 2 or Level 3 survey, which is a separate report from a different professional.
The rating, and the second one next to it
The headline is a letter, but underneath it is a number: the Standard Assessment Procedure score, out of 100. The bands are fixed, and knowing where you sit inside one tells you how much work a better letter takes.
- A: 92 or more. Rare outside new build with renewables.
- B: 81 to 91. New build territory.
- C: 69 to 80. The proposed future minimum for rented homes.
- D: 55 to 68. The most common band in England. See what an EPC rating of D means.
- E: 39 to 54. The current legal minimum to let a home.
- F: 21 to 38, and G: 1 to 20. Cannot be let without a registered exemption.
Beside the current rating sits a potential rating. That is the band the property would reach if every improvement on the certificate were carried out. A D with a potential of C is a cheap afternoon's work away. A D with a potential of D is telling you the easy measures are already done.
Every section, in order
Estimated energy costs
A three-year estimate of heating, hot water and lighting costs, with the saving the recommended measures would make. Treat it as a comparison between properties rather than a forecast of your bill. It assumes a standard household heating a standard number of rooms to a standard temperature, so a careful occupant beats it and a large family will not.
The features table
The most useful part of the certificate and the part nobody reads. It lists what the assessor found and rates each element from very poor to very good: walls, roof, floor, windows, main heating, heating controls, hot water, lighting. Two adjacent houses with the same band can have completely different problems, and this table is where you see which.
The recommendations
A ranked list of measures with an indicative installation cost and a typical yearly saving, ordered by value. This is a shopping list, already prioritised. It is generated from the standard method rather than written by hand, so it will sometimes suggest something impractical for your building, but the order is usually right. See how to improve an EPC rating for what each measure is really worth.
The assessor's details, and the reference number
Name, accreditation scheme and a report reference number. The scheme matters: only an assessor accredited by one of the government-approved schemes can lodge a certificate on the register, and a document produced by anyone else is worth nothing legally.
Who needs one, and when
- Selling a home: an EPC for selling a house must be commissioned before the property is marketed, and made available free to any prospective buyer. See EPCs when selling a house.
- Letting a home: a valid certificate of E or better before the tenancy is marketed, with a copy given to the tenant. See EPCs for landlords.
- A newly built or converted property: on completion.
- Applying for some grants or a green mortgage product: the lender will ask for the current certificate.
A handful of buildings are exempt, including places of worship, some temporary buildings and stand-alone buildings under fifty square metres. Listed buildings sit in a grey area that most owners resolve by getting one anyway.
How the certificate is produced
An accredited Domestic Energy Assessor visits, spends roughly forty minutes on an average house, and records the building rather than judging it. Construction and age of walls, roof and floor. Every window. The heating system, its fuel and its controls. Hot water and whether the cylinder is insulated. The proportion of low-energy lighting. Floor area, measured. Extensions and conservatories.
The assessor cannot assume anything they cannot see or evidence. That single rule decides more ratings than anything else. Cavity insulation behind plaster, underfloor insulation below a fitted floor, a boiler whose age is not on its plate: without paperwork, the method assumes the worst case for the building's age. Finding the cavity insulation guarantee before the visit is often worth more than any measure you could install that week.
The result is lodged on the national register, where it stays for ten years and is publicly searchable. See how to check the EPC register.
What an EPC does not tell you
- Whether the building is in good condition. It is not a survey and the assessor does not look for defects.
- Whether there is damp, mould or condensation. A cold, badly ventilated house can hold a respectable band.
- What the property is worth.
- What your bill will be, because the estimate assumes a standard household.
- Whether the recommended measures suit your building. Internal wall insulation on a solid-walled house has consequences the method does not weigh.
Getting one
Any accredited Domestic Energy Assessor can produce and lodge a certificate. Locally you will find independent assessors advertising from about £55, national booking platforms slightly higher, and estate agents who will arrange one with a margin on top. Compare the lodged, VAT-inclusive figure rather than the headline, and check the assessor is accredited before booking.
Where we stand
We do not produce EPCs yet. Our assessor accreditation is not on record, so nothing is assessed, lodged or charged until it is, and this guide exists because the question deserves a straight answer rather than a sales page. When it goes live, the plan is one visit for the certificate and the check-in inventory together. You can register interest and get one message on the day, or read what an EPC costs meanwhile.
Written by The Surveyor Co, a trading name of LW Renovation Group Ltd, Lincoln. This guide describes how records are written and read; it is not legal advice. Where a deposit scheme, lease or insurer sets a rule, that rule wins.