What an EPC is
An Energy Performance Certificate rates a property's energy efficiency from A (most efficient) to G (least). It's legally required when a home is built, sold or let, and is valid for ten years. The certificate is held on a public register, so you can look up most properties for free before you even view.
Alongside the rating, an EPC estimates energy costs and lists recommended improvements with their likely impact — useful for understanding what a home could achieve.
What the rating means in practice
A higher band generally means lower running costs and a warmer, cheaper-to-heat home. The difference between a band D and a band B can be substantial over a year. The EPC also shows a 'potential' rating — what the property could reach if the recommended measures were carried out.
Bear in mind the EPC is a modelled estimate based on the building's fabric and systems, not a precise bill. Older homes with solid walls often score lower, which doesn't make them bad homes — but it does flag where investment may be needed.
Why it matters to value and lending
Energy efficiency increasingly affects value and saleability. For landlords, minimum energy-efficiency standards already restrict letting the lowest-rated properties, and policy continues to tighten — so a poor EPC can mean future upgrade costs for buy-to-let buyers. Some lenders also offer 'green' mortgage incentives for efficient homes.
For owner-occupiers, a low EPC is mainly a guide to running costs and the work a property may need. Either way, it's a free, early signal worth checking before you offer.
Checking the EPC before you buy
You can search the public EPC register by address to see a property's current rating, floor area, and recommended improvements — often before booking a viewing. It's one of the quickest ways to size up a home's efficiency and likely running costs.
A TrueBrick report pulls the EPC for the address as standard — current and potential rating, property type and floor area — alongside the rest of the public record, so energy performance sits in context with everything else you should weigh before offering.
Frequently asked questions
How long is an EPC valid?
Ten years. A property being sold may have an EPC from a previous transaction that's still valid, though improvements made since won't be reflected until a new one is commissioned.
Can I be refused a mortgage over a low EPC?
It's rare for owner-occupier mortgages today, but energy efficiency is a growing factor, and for buy-to-let the minimum standards matter. A very low rating can signal upgrade costs ahead.
Does a new EPC cost much?
An assessment typically costs a modest fee (often under £100). Sellers must provide one, so as a buyer you usually don't need to commission your own.