EPC Methodology

1. Data sources, licence, and last update

The EPC section of a Home-Checker report is generated at the moment you run the report. We do not maintain our own EPC database — each report queries the official register live for the postcode (or the specific address, if you supplied one).

• Primary data: the EPC Register API for England and Wales, operated by the Department for Levelling Up, Housing and Communities (DLUHC) (now part of the Ministry of Housing, Communities and Local Government). The register is the statutory record of every domestic EPC lodged in England and Wales.
• Licence: the EPC Register is published as public data under the Open Government Licence v3.0, subject to the EPC Register's terms of use (registration with an email address and access token required).
• Lookup level: if you ran a property report we query by Unique Property Reference Number (UPRN) for the specific address. If you ran an area report we query by postcode and surface the most recently lodged certificate(s) at that postcode along with a postcode-level local-authority average rating.
• Recommendations: for the most recent certificate we additionally fetch the lodged improvement recommendations from the EPC recommendations endpoint.
• Last methodology update: May 2026. Data freshness: the EPC Register is updated as new certificates are lodged by accredited domestic energy assessors. Certificates appear in the register within days of lodgement; older certificates remain valid for ten years from issue.

2. What we do

For your address (or postcode), the Home-Checker EPC module queries the EPC Register and surfaces the most recently lodged certificate. From it we extract and present:

• The current energy rating (A–G) and current energy efficiency score (1–100), and the potential rating and score after the lodged recommendations.
• Building attributes as recorded on the certificate: property type, built form, total floor area, walls, roof, windows, main heating, heating controls, hot water and lighting — each with the assessor's rated efficiency.
• The annual energy cost estimates from the certificate for lighting, heating and hot water, plus a total.
• The lodged improvement recommendations, with indicative cost band, typical saving, and the resulting energy and environmental rating uplift.
• MEES compliance flag: a simple A–E vs F–G indicator of whether the rating meets the Minimum Energy Efficiency Standard (MEES) for domestic private rentals.
• A local-authority average rating, calculated by averaging the current energy rating across all certificates returned for the postcode at query time. This is an indicative comparator for the specific certificate you are looking at.

3. What we don't

We are deliberate about what falls outside the scope of this section so you can fill in the gaps with the right professional instrument when needed:

• We do not commission a new EPC, attend the property, or perform any survey of our own. The EPC you see is the certificate as lodged by the accredited assessor at the time it was issued.
• We do not verify that the certificate accurately reflects the property as it stands today. The fabric, heating system or insulation may have been upgraded (or degraded) since lodgement and the certificate will not reflect those changes until a new EPC is commissioned.
• We do not calculate an updated SAP / RdSAP score, model retrofit scenarios beyond what the certificate's own recommendations describe, or estimate EPC ratings for properties without a lodged certificate.
• We do not perform a Heat Loss Survey, undertake a thermographic survey, or assess airtightness, ventilation or moisture risk.
• We do not advise on grant eligibility (ECO, Boiler Upgrade Scheme, Great British Insulation Scheme), heat-pump suitability, or solar feasibility — the certificate's recommendations are indicative only.
• We do not cover Scotland, where the EPC scheme is operated separately by the Scottish Government via scottishepcregister.org.uk and uses different methodology. Home-Checker is currently England-only.
• We do not render EPCs for non-domestic buildings (commercial premises, listed buildings exempted from EPCs, etc.).

4. Known limitations

You should weight the EPC section with the following caveats in mind:

• Certificates expire after 10 years. An EPC is legally valid for ten years from the date of issue. A certificate older than that should be treated as historical context only — it is not a current legal compliance document.
• RdSAP is a model. Domestic EPCs are produced using Reduced Data Standard Assessment Procedure (RdSAP), a regulatory model that uses default assumptions where the assessor cannot directly observe a feature (for example, hidden insulation). Two assessors can produce different ratings on the same property within the model's tolerance. The score is an estimate, not a measurement of actual energy use.
• Cost figures are model-derived. Annual energy cost estimates on the certificate are based on standardised occupancy and the prices in force when the certificate was generated. Real bills depend on your tariff, occupancy patterns, and prevailing wholesale energy prices.
• Postcode-level data when no UPRN is supplied. If you ran an area report rather than a property report, or we could not match a UPRN, the certificates returned cover all properties at the postcode. The most recent certificate is shown; it may not correspond to your specific property.
• Recommendations may be partially completed. The certificate's recommendations were valid at the time of lodgement. Some may already have been implemented by the current owner without triggering a fresh EPC. We have no way to detect that.
• No certificate on file is not the same as a poor rating. Some properties have no lodged EPC because none has been required (e.g. owner-occupied without recent sale or letting). We will tell you the data is unavailable rather than guess.

5. What this is NOT a substitute for

6. Related

• Methodology overview — how the whole report is built
• Report Disclaimer — the full disclaimer
• Data Sources & Attribution — full list of upstream data sources