Why EPC assessors disagree, and how to dispute a rating you think is wrong

Across the UK, EPCs are produced under national rules but by individual accredited assessors using the evidence available on the inspection day. England, Wales, Scotland and Northern Ireland differ on complaint routes, validity rules and advertised-rating penalties, so the right answer depends on where the property is.

Why do two assessors give the same property different ratings?

Two assessors can give the same unchanged property different EPC ratings because the calculation depends on what each assessor can see, measure and evidence on the day, and the quality-control system tolerates some score movement rather than requiring identical SAP points. In England and Wales, accreditation schemes must ensure assessors carry out “consistent and accurate energy assessments in an independent manner,” but the scheme audit rule still treats an EPC as passing unless the cumulative error “exceeds 5 SAP points” or affects the recommendations or description enough to call the rating into question. That is why a flat can fall from C to D after a reassessment even if the fabric has not worsened: a different judgement on hot-water cylinder insulation, storage-heater controls, access to a loft hatch, or proof of retrofit works changes the inputs. Once a later certificate is validly registered or obtained, the practical certificate to rely on is usually the current one for that nation’s rules.

What evidence does an assessor need before crediting work you have already done?

An assessor needs either direct inspection or acceptable property-specific documentary evidence before crediting retrofit works, and missing paperwork or blocked access can make the EPC default back to the building’s assumed original specification. England, Wales and Northern Ireland use a broader RdSAP evidence rule: acceptable documentary evidence includes RSL correspondence, certificates, warranties, guarantees, or “any documents verifying that work has been carried out.” Scotland’s wording is narrower, listing RSL correspondence, certificates, warranties and guarantees, and Scotland does not accept evidence of intent to install, while England, Wales and Northern Ireland may accept intent only when it is later followed by proof. For U-values, RdSAP is stricter: “Documentary evidence applicable to the property being assessed” must be recorded before default values are overwritten. If storage heaters are repeatedly misidentified, give the assessor manuals, model numbers, data plates and photos before the visit; if loft access is blocked, arrange access before assessment rather than arguing afterwards.

How do you challenge an EPC rating you think is wrong?

You challenge an EPC rating by complaining first to the assessor, then escalating through the nation-specific route: the accreditation scheme in England, Wales and Northern Ireland, but in Scotland the route can end with the Scottish Government. England and Wales require approved schemes to facilitate “the resolution of complaints against members of the scheme,” and government guidance says that if the information is wrong, “a new EPC must be issued and the information on the register amended.” Northern Ireland has the same complaint-facilitation wording in its scheme rules, and EPC prices are market-set rather than fixed. Scotland is different: mygov.scot tells you to contact the assessor first, then the approved organisation, and then epcenquiries@gov.scot. Commissioning a fresh EPC may solve a practical problem faster than a complaint, but it can also replace the certificate position: England and Wales validity depends on whether a later EPC has been entered on the register, while Northern Ireland turns on whether a later EPC has been obtained by or provided to the relevant person. Abodient can hold the EPC certificate against each property and show its expiry, which matters because a portfolio landlord needs to know which certificate is current before marketing, letting or disputing a rating.

The property was advertised as EPC A but the certificate says B - is that misrepresentation?

In England, Wales and Northern Ireland, advertising EPC A when the certificate says B breaches the advertisement-duty penalty rule at a fixed £200, not a cap; Scotland’s penalty for a dwelling is £500, and the old Property Misdescriptions Act no longer applies because it was repealed in 2013. England and Wales require the energy performance rating “expressed in the energy performance certificate” to be stated in commercial advertising, and Northern Ireland uses the same certificate-matching approach; Scotland requires the advertisement to state the building’s energy performance indicator and enforces breach by penalty charge notice. A wrong advertised band can also matter privately: the live routes are a civil misrepresentation claim under the Misrepresentation Act 1967, if the buyer or tenant entered the contract and suffered loss, or a “misleading action” claim under the Digital Markets, Competition and Consumers Act 2024, which replaced the Consumer Protection from Unfair Trading Regulations after their April 2025 revocation. A small price reduction is therefore a negotiation point, not a statutory tariff.

Last reviewed August 2026.

Sources

• Energy Performance of Buildings (England and Wales) Regulations 2012, regulation 22 — “(a)for ensuring that members of the scheme carry out consistent and accurate energy assessments in an independent manner;” Source
• MHCLG Scheme Operating Requirements, Level 2 SORs v1.8 — “j. If this cumulative error exceeds 5 SAP points, or includes changes to the recommendations and/or description of the Energy Certificate in a manner which brings into question the accuracy of the rating, the audit shall be marked as a fail, and the Certificate shall be marked as defective and replaced.” Source
• RdSAP Conventions v12, 15 June 2025 — “Assume “as-built” if there is no evidence of retro-fitted insulation including:” Source
• Elmhurst Energy, Q&As on EPCs, June 2024 — “This means the data which is collected for the assessment is based on what an assessor can see and the evidence available to them on the day of the assessment.” Source
• Energy Performance of Buildings (England and Wales) Regulations 2012, regulation 24 — “Energy assessors must carry out energy assessments with reasonable care and skill.” Source
• RdSAP Conventions v12, convention 9.02, England, Wales and Northern Ireland — “Acceptable documentary evidence includes, but is not limited to, official correspondence from the applicable Registered Social Landlord (RSL) or certificates, warranties or guarantees or any documents verifying that work has been carried out.” Source
• RdSAP Conventions v12, convention 9.02, Scotland — “Acceptable documentary evidence includes, but is not limited to, official correspondence from the applicable Registered Social Landlord (RSL) or certificates, warranties, guarantees.” Source
• RdSAP Conventions v12, evidence of intent rule — “Evidence of intent to install does not on its own qualify as acceptable documentary evidence.” Source
• RdSAP Conventions v12, convention 3.08 — “Documentary evidence applicable to the property being assessed (see convention 9.02) must be provided and recorded if overwriting any default U-value.” Source
• GOV.UK EPC guide for marketing, sale and let of dwellings — “Where it is found that the information is incorrect a new EPC must be issued and the information on the register amended.” Source
• Energy Performance of Buildings (England and Wales) Regulations 2012, regulation 22 — “(f)for facilitating the resolution of complaints against members of the scheme;” Source
• Energy Performance of Buildings (England and Wales) Regulations 2012, regulation 9 — “(b)no other energy performance certificate for the building has since been entered on the register.” Source
• Energy Performance of Buildings (Certificates and Inspections) Regulations (Northern Ireland) 2008, regulation 8 — “(b)no other energy performance certificate for the building has since been obtained by or provided to the relevant person.” Source
• Energy Performance of Buildings (Scotland) Regulations 2008, regulation 6 — “(b)for all other purposes, on the expiry of a period of 10 years from the date on which the document was issued.” Source
• mygov.scot, complain about an EPC — “If you think the Energy Performance Certificate (EPC) is wrong, contact the assessor who produced it.” Source
• Department of Finance Northern Ireland, EPC FAQs — “The price of an energy performance certificate is determined by the market.” Source
• Energy Performance of Buildings (England and Wales) Regulations 2012, regulation 11 — “Where a building or building unit to which this regulation applies is offered for sale or rent on or after 9th January 2013 the, relevant person, or, where applicable, a person acting on behalf of the relevant person, must ensure that the energy performance rating of the building expressed in the energy performance certificate is stated in any advertisement of the sale or rental in commercial media.” Source
• Energy Performance of Buildings (England and Wales) Regulations 2012, regulation 38 — “(e)in relation to a breach of a duty under regulation 11(2) or 35(5), £200.” Source
• Energy Performance of Buildings (Certificates and Inspections) Regulations (Northern Ireland) 2008, regulation 5A — “The relevant person, or where a person is acting on his behalf that person, shall ensure that the energy performance indicator of the building as expressed in the energy performance certificate is stated in any advertisement for sale or rent of the building in commercial media.” Source
• Energy Performance of Buildings (Certificates and Inspections) Regulations (Northern Ireland) 2008, regulation 35 — “(e)in relation to a breach of duty under regulation 5A(2) or 32(4), £200.” Source
• Energy Performance of Buildings (Scotland) Regulations 2008, regulation 5A — “Subject to paragraph (2), where a building or building unit is offered for sale or let, the owner of the building or building unit must ensure that any advertisement in commercial media offering the building or building unit for sale or let, as the case may be, states the energy performance indicator for that building or building unit.” Source
• Energy Performance of Buildings (Scotland) Regulations 2008, regulation 17A — “An enforcement authority may, if it believes that an owner has breached any duty under regulation 5A, give a penalty charge notice to the owner.” Source
• Energy Performance of Buildings (Scotland) Regulations 2008, regulation 17 — “(i)£500 for dwellings or buildings (or building units) that are ancillary to dwellings; or” Source
• Scottish Government EPC reform update — “The Scottish Government can confirm that the majority of the Energy Performance of Buildings (Scotland) Regulations 2008 and current EPC system will now remain in place until Spring 2028, at which point the outstanding provisions of the Energy Performance of Buildings (Scotland) Regulations 2025 will enter into force.” Source
• Property Misdescriptions Act 1991 (Repeal) Order 2013 — “The Property Misdescriptions Act 1991 is repealed.” Source
• Digital Markets, Competition and Consumers Act 2024, section 226 — “(a)the provision of false or misleading information relating to a product, a trader or any other matter relevant to a transactional decision,” Source
• Digital Markets, Competition and Consumers Act 2024, section 251 — “The Consumer Protection from Unfair Trading Regulations 2008 (S.I. 2008/1277) are revoked.” Source
• Misrepresentation Act 1967, section 2 — “Where a person has entered into a contract after a misrepresentation has been made to him by another party thereto and as a result thereof he has suffered loss, then, if the person making the misrepresentation would be liable to damages in respect thereof had the misrepresentation been made fraudulently, that person shall be so liable notwithstanding that the misrepresentation was not made fraudulently, unless he proves that he had reasonable ground to believe and did believe up to the time the contract was made the facts represented were true.” Source
• GOV.UK EPC guide for marketing, sale and let of dwellings — “The potential rating shown on the EPC is based on all cost-effective recommendations being implemented.” Source