If you think your EPC is wrong, go back to the assessor who produced it first, and if that does not sort it out, complain to their accreditation scheme, whose details are printed on the certificate. The certificate itself tells you to do exactly that. Before you do, it is worth checking whether it is really a mistake, because a lot of “wrong” EPCs are correct certificates that measure something different from what people expect.
First, check whether it is actually wrong
Three things catch people out.
It measures the building, not your bills
The A to G rating shows how cheap or expensive the home would be to run for a standard household. It does not look at how you use it, so a low bill does not mean the rating is wrong. How the ratings work goes into this.
It can only record what could be seen or proved
The assessment is non-invasive: nothing is drilled or lifted. If part of the home could not be reached, or insulation could not be seen and there was no paperwork for it, the methodology fills the gap with a default based on the property’s age and type. Look at the table of features on your certificate. Anything marked “assumed” is one of those defaults, and it is usually the best place to start.
The basic facts
Check the property type, the total floor area, the heating system and the glazing against what you know about the home. An extension or a loft conversion that has been missed, or a boiler described as older than it is, is a genuine error and worth raising.
Step 1: go back to the assessor
The certificate says: “If you’re unhappy about your property’s energy assessment or certificate, you can complain to the assessor who created it.” Their name, phone number and email are on it, in the section about contacting the assessor.
Say exactly which entries you think are wrong, and send whatever proves it: a cavity wall insulation guarantee, loft insulation receipts, the boiler installation certificate, window certificates, a building control completion certificate for an extension, or clear photos. Elmhurst Energy, the largest accreditation scheme, says an assessor should put genuine problems right at no cost to the homeowner.
Step 2: the accreditation scheme
If you are still unhappy after contacting the assessor, the certificate tells you to contact the assessor’s accreditation scheme. The scheme’s name and phone number are printed next to the assessor’s. Schemes are appointed by the government to make sure assessors are qualified; they mediate between you and the assessor, and they audit certificates. When a certificate is found to be defective, it is taken off the register and replaced with a correct one.
Or: have the home assessed again
If the certificate was right when it was done but the home has changed since — a new boiler, insulation, new windows, an extension — there is nothing to complain about. A new assessment is how that work gets recorded, and the newest certificate is the one that counts. Have the paperwork ready: evidence is what changes a rating, not the choice of assessor. How to improve your EPC rating lists what to look for.
What does not count as a wrong EPC
- Your bills are lower than it suggests. It assumes a standard household, not yours.
- Recommendations that do not suit your home. They are generated by the software from the national methodology, so the same measures turn up on a lot of certificates.
- A rating you were hoping would be higher. If the entries are right, the rating is right.
If it is one of mine
Get in touch and tell me what you think is wrong — that is step one above. If I have got something wrong, I will put it right. Contact details and the quote form are on the home page.
Common questions
Can I challenge my EPC rating?
Yes. Contact the assessor who produced it first. If you are still unhappy, contact their accreditation scheme, whose details are printed on the certificate.
Who pays to correct a wrong EPC?
Elmhurst Energy, the largest accreditation scheme, says an assessor should put genuine problems right at no cost to the homeowner.
Why does my EPC say “assumed”?
Assumed ratings are used for features the assessor could not inspect, based on the property’s age and type. Evidence such as an insulation guarantee lets a new assessment record what is really there.
Can two assessors give the same house different ratings?
They follow the same methodology, so they should land in the same place. Differences usually come from what could be seen or evidenced on the day.
Do I need a new EPC after making improvements?
Not by law, but the newest certificate is the one that counts, so a new assessment is how improvements get recorded.
Where to go next
What the A to G bands and the score mean, and the paperwork and measures that move a rating.