Guidance

Understanding Commercial EPC Ratings

How the A–G rating is calculated and what it means for compliance.

Note: This is a general guide for UK commercial property owners and professionals. Non-domestic EPC regulations, registers and processes differ across England & Wales, Scotland and Northern Ireland. Always check the current position on GOV.UK and the relevant national register before acting on any specific matter.

How the band is calculated

The rating is an index: the building's modelled CO₂ emissions compared with a notional building of the same size, shape and activity mix built to a defined standard. A score of 50 sits at the B/C boundary, 100 marks the D/E boundary; lower is better.

Because the comparison is against a notional equivalent, a large distribution warehouse and a small office are judged against different baselines — the letter is not a straight comparison of energy use between building types.

What moves the number

Heat generator efficiency and fuel type dominate most results, followed by lighting power density and controls, then fabric performance and air permeability. Grid-supplied electric heating tends to score badly; heat pumps and on-site renewables score well.

Reading the recommendation report

The recommendations are generated by the software against generic payback categories. They are a useful starting list but not a specification — a targeted improvement study is the right next step where a band change is needed.

Next steps

If you'd like specific advice about a property or portfolio, request a quote and our in-house assessors will come back to you.

Related guidance

Need a Commercial EPC anywhere in the UK?

Send us the property details and our team will review the requirements before providing a tailored quotation.