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.
On site
The assessor measures or verifies floor areas, records construction of walls, roof, floors and glazing, and inventories the fixed building services — heat generators, cooling plant, ventilation, lighting types and controls, hot water and any renewables. Meter readings and occupancy patterns are not part of the asset rating, but plant nameplates, efficiencies and control strategies are.
Evidence matters. Where a specification cannot be verified on site or from documents, the software applies conservative default values, which almost always produces a worse rating than reality.
How long it takes
A small retail unit or single office suite is typically an hour or two on site. A multi-let office building, hotel or large industrial unit can take most of a day, and complex buildings requiring Level 5 dynamic modelling take longer again at the modelling stage than on site.
Access requirements
The assessor needs access to plant rooms, roof voids where safe, riser cupboards, and each demised area being assessed. Arranging keys and escorts in advance is the single biggest factor in avoiding a return visit.
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.