What is an EPC and when do you need one?

Who is exempt

A small number of building types are excluded from the requirement altogether, generally because an energy rating is not a meaningful concept for them or because of their protected status. These exemptions are narrow and are frequently misapplied by sellers assuming their property qualifies when it does not — a listed building, for example, is not automatically exempt, and an exemption only applies where meeting the required energy standards would unacceptably alter its character. Getting this wrong can hold up a sale at exchange, since conveyancing solicitors routinely check for a valid certificate before contracts complete.

• Places of worship
• Temporary buildings used for two years or less
• Standalone buildings under 50 square metres not used for extended occupation
• Buildings due for demolition with the relevant consents in place
• Listed or officially protected buildings, only where meeting minimum standards would unacceptably alter their character

How an EPC differs from other property documents

It is common for sellers and tenants to conflate an EPC with a homebuyer survey, a gas safety certificate or an electrical installation condition report, but each does a different job. A homebuyer survey assesses structural condition and defects. A gas safety certificate confirms appliances are safe to use. An EICR checks the fixed electrical installation. An EPC does none of this — it is exclusively about energy performance and theoretical running costs, calculated from a fixed set of inputs rather than a judgement about the building's overall condition or safety.

How the assessment is carried out

A domestic energy assessor visits the property and records the relevant features using a tape measure, torch and camera, checking loft insulation depth, wall construction, glazing units, and the make and model of the boiler or heat pump where visible. The visit for a typical house takes between 30 and 60 minutes depending on size and how accessible the loft and meter cupboards are. The assessor cannot make assumptions about hidden insulation without evidence, so it helps to have any documentation for cavity wall insulation, loft top-ups or double glazing installation to hand, since this can move the rating meaningfully without any further work being done to the property.

• Book the assessment and provide access to all rooms, the loft and the meter cupboard
• Assessor records construction, glazing, heating and lighting on site
• Data is entered into RdSAP software to calculate the rating
• Certificate is generated and lodged on the EPC Register
• Recommendations report is issued alongside the certificate

What happens if you skip it

Trading Standards enforces the requirement for both sales and lettings, and a missing or invalid EPC can result in a penalty, typically a fixed fine per property, alongside the practical problem of not being able to complete a sale or start a tenancy cleanly. For lettings, there is a further consequence: a landlord who has not provided a valid EPC before the tenancy started may find it harder to serve a valid Section 21 notice later, since the prescribed information requirements are linked to having supplied the correct documents at the right time.

Getting an EPC quickly

Because the EPC is often the last document chased before marketing starts, turnaround speed matters in practice more than most guidance admits. A same or next-working-day survey and lodgement removes it as a bottleneck, and for chains under time pressure this is usually worth paying a small premium for over booking the cheapest available slot several weeks out.