Commercial vs Domestic EPCs: Key Differences Explained

Not all EPCs are the same. The type of certificate you need depends on whether your property is residential or commercial. Here is how the two types differ.

Domestic EPCs

Domestic EPCs apply to residential properties — houses, flats, bungalows and maisonettes. They are produced using the Reduced Data Standard Assessment Procedure (RdSAP), which is a simplified version of the full SAP calculation used for new builds. The assessment looks at the building fabric, heating systems, hot water, lighting, and ventilation. Domestic EPCs are carried out by a Domestic Energy Assessor (DEA).

Commercial EPCs

Commercial or non-domestic EPCs apply to properties used for business purposes — offices, shops, restaurants, warehouses, factories and more. They are produced using the Simplified Building Energy Model (SBEM) methodology, which is more complex than RdSAP. Commercial assessments consider additional factors like air conditioning systems, mechanical ventilation, and the specific use of different areas within the building. They must be carried out by a Non-Domestic Energy Assessor (NDEA) who holds Level 3, 4 or 5 accreditation depending on the building's complexity.

Display Energy Certificates (DECs)

Public buildings over 250 square metres are required to have a Display Energy Certificate (DEC), which is different again from a standard EPC. A DEC shows the actual energy consumption of the building based on meter readings and energy bills, rather than a theoretical assessment. DECs must be displayed in a prominent place within the building.

Which Do You Need?

If your property is a dwelling (where people live), you need a domestic EPC. If it is a commercial premises, you need a non-domestic EPC. Mixed-use buildings may need both. If you are unsure, get in touch with us and we can advise on the correct type for your property.