Domestic energy efficiency
A is most efficient. G is least efficient.
What the assessment looks at
The assessor records relevant features of the dwelling: its construction, insulation, openings, heating, hot water and controls. A model uses standard assumptions to produce the rating. It does not measure how much energy a particular household will use.
Make the address unambiguous
For a flat, include the flat number, access entrance and any shared heating arrangement. Tell us about extensions, conversions and substantial changes since the last certificate. Check the government register first; an existing record may already answer your immediate need.
Evidence is useful when work is hidden
Documents for insulation, glazing or heating can help explain features that are no longer visible. Keep the evidence with the part of the building it relates to. An assessor cannot simply assume that a concealed upgrade has been installed.
Use the result for the right purpose
Read the description and recommendations alongside the A–G band. A suggested improvement is not an installation quote, and a potential rating depends on suitable measures being completed. Ask about assumptions before planning expenditure.
Getting ready
- Find the current EPC, if there is one.
- Gather records of heating, insulation and alterations.
- Arrange normal access to the agreed rooms and equipment.
- Tell us about a keyholder, restricted areas or shared services.
The output to agree
An EPC and its recommendations, where the agreed assessment can be completed and lodged.
Work outside this brief
This instruction does not include installation, a measured energy-use survey or a guaranteed future rating. A new-build dwelling may need SAP assessment instead.
Questions about Domestic EPC
Should I book if an EPC already exists?
Start by finding the existing certificate and checking the exact address. Ask whether it is suitable for your purpose before ordering a fresh assessment.
Will the rating predict my bills?
No. The result follows a standardised model. Occupancy, weather, tariffs and how the home is used affect actual costs.
What if the address has more than one dwelling?
Describe each unit and its access. The assessment boundary and number of certificates must be agreed.