Understanding your domestic EPC: ratings, recommendations and next steps

An Energy Performance Certificate describes a home's calculated energy performance. It helps you understand the building and consider potential improvements, but it is not a record of the current occupier's actual bills. Before making decisions, read the whole certificate and check that it relates to the correct property.

Start with the property details

Check the address, dwelling description and assessment information. A report for another flat or for a building before significant alterations may not answer the question you are asking now. If something looks inaccurate, contact the assessor or the relevant accreditation scheme through the details provided on the certificate. Do not edit the certificate yourself.

Read the rating in context

Domestic EPCs use an A-to-G energy efficiency rating. The assessment uses standardised assumptions about the building's construction and services, rather than measuring how one household lives. Heating habits, occupancy, weather and energy tariffs affect actual bills, so two households in similar homes can spend different amounts.

The rating should be read alongside the recorded property features. Insulation, heating, windows, controls and other evidence help explain the assessment. Where evidence is missing, the assessment methodology may use assumptions; an installation invoice or suitable technical record can therefore be useful to discuss before the visit.

Understand current and potential performance

A certificate may show current performance and an indication of what recommended improvements could achieve. Treat potential performance as a modelled outcome under the assessment assumptions. It is not a guarantee that one selected measure will produce a particular rating, bill reduction or financial return.

The recommendations are a starting point. A suitable plan should also consider ventilation, moisture, the condition of the building, practical constraints and the interaction between measures. If work affects a shared building or a property with particular restrictions, establish what advice and permissions are needed before commissioning it.

Prepare useful evidence

Gather previous reports, insulation records, heating installation documents and information about extensions or conversions. For a flat with communal heating, ask the building manager whether relevant system information is available. Explain what records are missing rather than guessing specifications.

Keep the assessment practical: arrange safe access to the areas and equipment the assessor needs to see. You should not dismantle equipment or disturb unfamiliar materials to prepare for a visit.

Choose your next step

If you need a new assessment, view our Domestic EPC service. If your priority is planning improvements, explore an EPC improvement plan or retrofit assessment. Different services answer different questions; an EPC does not replace a structural survey, gas inspection or electrical condition report.

Further reading

GOV.UK: Energy Performance Certificates

GOV.UK: Find an energy certificate

GOV.UK: Guide to domestic EPCs