What Happens During an EPC Assessment?
A step-by-step walkthrough of a domestic EPC assessment, from arrival to lodgement, so you know exactly what to expect on the day.
By First Certify · 2025-08-05 · 5 min read
First Certify is a UK property compliance platform staffed by accredited assessors and qualified engineers. This article has been reviewed for accuracy against current UK regulations, including MEES, the Electrical Safety Standards 2020, and the Gas Safety (Installation and Use) Regulations 1998.
An EPC assessment is a straightforward, non-invasive survey that takes 30 to 45 minutes for a standard domestic property. Understanding what happens on the day helps you prepare and ensures the assessment goes smoothly.
When the assessor arrives, they will introduce themselves and explain the process. They are accredited by Elmhurst or Stroma and carry ID. You do not need to move furniture or prepare the property beyond ensuring access to key areas.
The assessment begins with the exterior. The assessor photographs the property from the front and rear to record the construction type, age, and any extensions. They note the wall type (solid, cavity, or timber frame), the roof type, and any visible insulation.
Inside, the assessor inspects the main rooms, the loft, and the heating system. They look at the boiler or heating system, its make, model, and age. They check the hot water cylinder if present, and note the thermostat and controls. They inspect the loft for insulation depth and condition.
In each room, the assessor counts the fixed light fittings and checks the proportion of low-energy bulbs. They note the window type (single, double, or triple glazing) and the frame material. They also check for any secondary heating, such as electric fires or storage heaters.
The assessor photographs key features for evidence: the boiler data plate, the loft insulation, the glazing units, and the heating controls. These photos are required by the accreditation scheme as proof of the assessment.
After the visit, the assessor enters the data into the RdSAP software, which calculates the energy efficiency rating (A to G) and the environmental impact rating. The certificate is then lodged on the national EPC register, usually within 72 working hours (most within 24–48), and a digital PDF is emailed to you.
No work is carried out during the assessment. It is purely an inspection. The assessor will not move furniture, lift floorboards, or open sealed cavities. Everything is visual and non-invasive.
FAQs
How long does an EPC assessment take?
A standard domestic EPC assessment takes 30 to 45 minutes. Larger properties may take up to an hour. The assessor needs access to all main rooms, the loft, and the boiler.
Do I need to prepare my property for the assessment?
No major preparation is needed. Ensure the assessor can access the loft, the boiler, and all main rooms. Make sure fixed light fittings have working bulbs installed.
Is the EPC assessment invasive?
No. The assessment is purely visual and non-invasive. The assessor will not move furniture, lift floorboards, or open sealed cavities. They will photograph key features for evidence.