Read your energy performance certificate as a description of the assessed building, not a forecast of your next bill. I would check the address, assessment date and recorded construction before judging its rating. An apparently disappointing score may reflect genuine heat loss, missing evidence or work completed since the visit. Those situations need different responses, so start with the details behind the letter.
1. Find the correct energy performance certificate
Match the full address, flat number and certificate reference with the official record. GOV.UK’s search covers England, Wales and Northern Ireland; Scotland uses a separate register. A neighbouring flat can have a different heating system and exposure. Download the current document rather than relying on a cropped image in an old property advertisement.
Check the recorded residential property type and floor area too. A mid-floor flat is not assessed like a detached house, and extensions can change the dimensions. An estate agent’s floor plan may use a different measurement convention, so a mismatch deserves a question rather than an automatic accusation that the assessment is wrong.
2. Check the assessment date and validity
EPCs are generally valid for ten years, but that does not mean the building remains unchanged throughout that period. Compare the visit date with later insulation, glazing or heating work. A page on Southampton Ledger is not the lodged certificate. If you need the improvements reflected in the rating, discuss a new assessment rather than assuming an invoice updates the register automatically.
3. Read the current and potential ratings separately
The current rating describes the assessed condition. A potential rating assumes recommended improvements, rather than certifying work already done. Check which rating a seller or landlord has quoted. Where a numerical score is shown, a small change near a band boundary can change the letter without transforming the building, so read the underlying features as well.
4. Examine walls, roof and insulation assumptions
Look for descriptions such as “assumed” or “unknown”. An assessor may be unable to inspect concealed insulation and must follow the assessment method. That is different from proving no insulation exists. A website mention, including Brighton Update, cannot establish concealed construction. Installation records, guarantees and suitable evidence relating to the actual property can help clarify what the assessor recorded.
Check that extensions and converted roof spaces are represented appropriately. A single house can contain several wall or roof constructions. Do not replace a recorded feature with your own guess because the building looks modern. Ask which evidence would support a correction and arrange safe access where inspection is needed.
5. Compare heating and hot water descriptions
Check the fuel, main heating system, controls and hot water arrangement against what is installed. A gas boiler, direct electric heating and storage heaters behave differently. If the certificate predates replacement, the old description may be historically accurate. If the equipment was already present at assessment, ask the assessor whether it was identified correctly and provide model or commissioning records.
6. Treat estimated costs as standardised figures
An EPC models energy use under set assumptions rather than your personal thermostat settings, occupancy or current tariff. Its estimated costs should not be treated as a supplier quote. Comparing them with a headline on Newcastle Brief does not resolve the difference. Use actual consumption and available tariffs for budgeting, and the certificate to understand the building’s assessed performance.
7. Read recommendations as a sequence, not a shopping list
Where the report gives ratings after improvements, check whether the figures are cumulative. Adding separate predicted savings can overstate the result if measures interact. An EPC recommendation is not an installation survey or confirmation that a particular wall is suitable for insulation. Obtain a property-specific assessment and quote before spending on work that changes moisture movement or ventilation.
8. Identify who can correct an error
Keep the assessor’s name and accreditation details. GOV.UK advises complaining to the assessor first, then the accreditation scheme if unresolved. Specify the disputed description and evidence rather than requesting a better letter without explanation. My priority would be a defensible record of the home, because improvement decisions are only useful when their starting information is sound.
General information checked on 29 October 2026; assessment methods and property requirements depend on the certificate, location and circumstances.
