Preparation guide
How to prepare for your EPC assessment
An assessor can only count what can be seen, measured or proven. Fifteen minutes of preparation, and a few documents you may already have, can be the difference between one band and the next.
- Clear access to
- Loft, boiler, cylinder, meters
- Find
- Insulation, window and boiler paperwork
- Visit length
- 30 minutes to 2 hours
- Survey type
- Non-invasive
Why evidence decides the rating
Since 1 October 2026 every energy assessor in England and Wales has worked to minimum evidence requirements. The principle behind them is that an auditor must be able to replicate the certificate from the assessor's evidence alone: floor plans, site notes, photographs and documents.
That is good for accuracy, and it has one practical consequence for you. If something cannot be seen and there is no paperwork for it, we have to record it as unknown. The calculation then assumes whatever was typical when the house was built. For a 1930s semi, that means walls with no insulation, whatever was pumped into the cavity in 1998.
The house on the right shows the eight things every survey records.
- Loft insulation, with the depth measured
- Wall construction and thickness
- Every window: type, age and size
- Boiler, radiators and heating controls
- Hot water cylinder and its insulation
- Lighting in every fixed fitting
- Fans, flues and chimneys
- Solar panels, batteries and meters
Before we arrive: access
- The loft hatch. Clear the space beneath it. We need to see the insulation and measure how deep it is.
- The boiler. We photograph the data plate that shows its make and model, so empty the cupboard if it is boxed in.
- The hot water cylinder. Airing cupboards are often full. We need to see the cylinder, its insulation and its thermostat.
- Heating controls. The programmer, the room thermostat and the valves on the radiators.
- The meters. Gas and electricity, wherever they are.
- Every room. That includes locked bedrooms in a shared house, the conservatory and any room in the roof.
Documents worth finding
Paperwork counts when it relates specifically to your property and can be independently checked. These are the documents that most often change a rating.
| For this | Look for |
|---|---|
| Cavity wall insulation | The installer's guarantee or certificate. Without it, we look for the pattern of drill holes in the brickwork. |
| Internal or external wall insulation | Installer paperwork or a building control completion certificate showing what was fitted and how thick it is. |
| Loft insulation under boards | An invoice or certificate stating the depth, or photographs taken while it was laid. |
| Floor insulation | Certificates, or photographs from the work. |
| Replacement windows and doors | A FENSA certificate, or the equivalent building control certificate, which gives the installation date. |
| A new boiler or heat pump | The installation certificate and the manual. We also photograph the data plate. |
| Extensions and loft conversions | The building control completion certificate, which fixes the date and the standard it was built to. |
| Solar panels and batteries | The MCS certificate or handover pack showing the size of the system and the battery capacity. |
| Airtightness | An air pressure test certificate, if the home has ever had one. |
Documents support a survey. They cannot replace a photograph we could reasonably have taken ourselves.
On the day
- We walk round with you or whoever is letting us in, and ask about the age of the house and any work that has been done.
- We measure every floor and note the size and direction of each window.
- We photograph the outside on every side we can reach, then the loft, heating, hot water, lighting and meters.
- We look at your documents and photograph the relevant pages.
Nothing is drilled, lifted or moved. Most homes take between 30 minutes and 2 hours.
If you are a landlord
Tell your tenant when we are coming and what we need to see. A locked room or a loft hatch behind a wardrobe is the most common reason for a second visit. If you hold the paperwork and will not be there, email it to us beforehand.
Source: Energy Assessor Scheme Operating Board, Minimum Evidence Requirements for Domestic Energy Assessors, version 1.1, effective 1 October 2026; Elmhurst Energy. The exact evidence we can accept is set by the conventions our accreditation schemes apply.
Preparation questions
Small things that make a difference.
Do I need to be at home for the assessment?
Someone needs to let us in and give access to every room. That can be you, a tenant or your agent, and they do not need to follow us round.
Will you move furniture or lift carpets?
No. The survey is non-invasive. We only record what can be seen, measured or evidenced with documents.
What if I cannot find any paperwork?
We record what we can see and measure. Anything hidden and undocumented is entered as unknown, and the calculation uses the assumption for a home of that age. The installer or the guarantee provider may be able to send a copy, and your council's building control team may hold records for extensions and replacement windows.
Can I send documents after the visit?
Yes, but do it quickly. It is far easier to include evidence before the certificate is lodged than to change things afterwards, so send what you have within a day or two.
Do photographs I took during building work count?
They can help, provided they clearly show your property. Dated photographs of insulation going in, together with an invoice, are much better than nothing. Whether they can be used depends on the evidence conventions we have to follow.