What does my EPC rating mean?
An EPC rating tells you how energy efficient a home is, from A (best) to G (worst). Here is what the bands and scores mean and what they do not tell you.
Your EPC rating is a band from A to G that sums up how energy efficient your home is, based on a score out of 100 that reflects estimated running costs.
Band A homes are the cheapest to run for their size, and band G homes are the most expensive.
In this guide you will learn what each band covers, how the score is worked out, how long a certificate lasts and why a rating can look wrong.
This is general information, so for decisions about selling, letting or spending money it is a good idea to check the official guidance or speak to a qualified adviser.
What are the EPC bands and scores?
There are seven bands, with a higher score in a better band.
| Band | Score | What it generally means |
|---|---|---|
| A | 92 and above | Very efficient. Typically a modern or heavily upgraded home with low running costs. |
| B | 81 to 91 | Efficient. Many new-build homes land here. |
| C | 69 to 80 | Better than average. The level many policies and lenders treat as a good target. |
| D | 55 to 68 | Around the middle. Often a home with some insulation but room to improve. |
| E | 39 to 54 | Below average. Likely to have gaps in insulation or an older heating system. |
| F | 21 to 38 | Poor. Running costs are likely to be high and improvement potential large. |
| G | 1 to 20 | Very poor. The least efficient band, usually with several major improvements available. |
The thresholds come from the government's standard method for rating homes, and the descriptions are our plain-English summary rather than official wording.
How is an EPC rating worked out?
An accredited energy assessor surveys the property and enters what they find into approved software, which calculates a score.
The assessor looks at things like walls, roof, floors, windows, the heating system and controls, hot water and lighting.
The calculation estimates the cost of heating, hot water and lighting for a standard household, so it does not count appliances such as a washing machine or television.
Because many details cannot be seen, assessors sometimes record an assumption, such as "cavity wall, as built, no insulation (assumed)", which is why you may see that wording on a certificate.
What is the difference between current and potential rating?
The current rating is where the home is today, and the potential rating is what it could reach if all the recommended improvements were made.
The potential figure assumes every listed measure is installed, which may not be practical or affordable for everyone.
The certificate also lists the improvements in a suggested order, with indicative costs and typical yearly savings, which makes it a useful starting point for planning.
You can look up a certificate to see both figures for a property, and our guide to improving your EPC rating explains the common measures.
How long does an EPC last?
An EPC is valid for 10 years from the date it was lodged on the register.
You can use the same certificate for as long as it is valid, even if you sell or let the property several times.
If you make significant improvements, it may be worth getting a new assessment, because the old certificate will not reflect the upgrade.
An expired certificate is not deleted, so you can still view it, but it can no longer be relied on for marketing a property.
Why does my EPC rating look wrong?
A rating can look wrong because it uses assumptions, may be out of date, or may not reflect work done after the assessment.
- It is old. Improvements made since the assessment, such as new insulation or a new boiler, will not appear until a new EPC is lodged.
- It relied on assumptions. Where the assessor could not see insulation, the software uses age-based defaults, which can understate the real position.
- It followed a different method. The calculation method has been updated over time, so older and newer certificates are not always like for like.
- It was wrong at the time. Assessors can make mistakes, and you can raise a concern with the assessor's accreditation scheme, or ask for a reassessment.
Does the EPC rating matter?
It matters for legal requirements when selling or letting, for some lenders and grant schemes, and as a guide to likely running costs.
Some mortgage products reward more efficient homes, and some government help depends on a property's current band, as explained in our guide to EPC grants and ECO4.
It is not the whole story, because two homes in the same band can still cost different amounts to run, depending on the people who live in them.
Common questions
Is a higher EPC score better?
Yes. The score runs from 1 to 100 or more, and a higher number means a more energy efficient home with lower estimated running costs.
Does my EPC show my actual energy bills?
No. It estimates costs using standard assumptions about how a typical household heats and uses the home, so your real bills will differ.
Do I need an EPC to sell or rent out a home?
In England and Wales you generally need a valid EPC to market a home for sale or to let. The seller or landlord is normally responsible for providing it.
Can I let a property with a low EPC rating?
Minimum ratings apply to rented homes in England and Wales, set at band E at the time of writing, and the government has proposed raising them, so check the latest GOV.UK guidance before you let a property.
Why is my EPC rating different from my neighbour’s?
Two similar-looking homes can score differently because of extensions, heating systems, insulation, glazing, the age of the assessment and the information the assessor had on the day.