How to Prepare for Your EPC Assessment: A Simple Checklist

Booking an Energy Performance Certificate is the easy part. The bit most people get wrong is preparation, and it can genuinely cost you a band on your rating. An EPC assessment is non-invasive and quick, but the assessor can only record what they can see and what you can prove. This checklist covers exactly what to have ready before we knock on your door.

If you want a step-by-step account of the visit itself, read our companion guide on what happens during an EPC assessment. This article focuses on what you can do beforehand.

What the assessor needs access to

A domestic EPC is produced by a Domestic Energy Assessor (DEA) walking through the property and recording its construction, heating and insulation. That means physical access matters more than anything else.

Every room

The assessor measures the property and notes the heating in each room, so every room needs to be accessible, including:

• Bedrooms, even if someone is working from home in one
• Bathrooms and en-suites
• Utility rooms, cupboards housing the boiler or cylinder
• Conservatories and extensions
• Integral garages

Locked rooms are a common problem in shared houses and tenanted properties. If a room cannot be accessed, the assessor has to make assumptions, and assumptions rarely work in your favour.

The loft hatch

Loft insulation is one of the biggest single influences on a rating, and the assessor needs to look into the loft to measure its depth. Before the visit:

• Make sure the loft hatch is not painted shut or screwed closed
• Move wardrobes or stored boxes blocking the hatch
• If the loft is boarded over the insulation, dig out any paperwork showing what was installed underneath

If the assessor cannot inspect the loft and you have no documentation, the insulation has to be recorded as unknown, which usually means a default value based on the property's age.

The boiler and hot water cylinder

The heating system is the other heavyweight in the calculation. The assessor needs to read the make and model from the boiler's data plate, so clear access to the boiler cupboard helps. If you have a hot water cylinder, they will check its insulation and look for a thermostat on the side. Heating controls matter too: room thermostats, programmers and thermostatic radiator valves are all recorded.

Gas and electricity meters

The assessor confirms which fuels the property uses and whether the electricity meter is a standard or dual-rate type. If your meters are in a communal cupboard or behind a locked panel, have the key ready.

Paperwork that lets improvements be credited

This is the part most homeowners skip, and it is the one that most often makes a difference. Under RdSAP, the methodology used for existing homes, an assessor can record an improvement only where it can be seen or where there is documentation they can accept. Where neither is available, the methodology may require a default assumption based on the age and type of property — and that default can be less favourable than what is actually installed.

It is worth being precise about what this means: evidence changes what can legitimately be recorded, not what the rating will be. None of the documents below is compulsory, and having them does not guarantee a better result. They simply make it less likely that a genuine improvement goes uncredited.

Worth digging out before the visit:

• Cavity wall insulation certificates (often from CIGA or the installer). Injected insulation is invisible from inside the home, so without paperwork an older property may be recorded as having uninsulated walls.
• FENSA or CERTASS certificates for replacement windows, which evidence the installation date and standard of your double glazing.
• Building regulations completion certificates for extensions, loft conversions or major renovations, which can evidence insulation levels in the new fabric.
• Boiler installation and commissioning paperwork, especially useful if the data plate is worn or the model is obscure.
• MCS or commissioning documentation for solar panels (photovoltaic or solar thermal), which can confirm the installed capacity rather than leaving it to be estimated. MCS paperwork is one acceptable form of evidence, not a requirement.
• Receipts or guarantees for loft, floor or room-in-roof insulation where the material cannot be seen directly.

Since RdSAP 10 became the approved methodology for existing dwellings on 15 June 2025, assessors record more detail than before, so good documentation is worth having to hand. Photographs of paperwork are usually fine; originals are not required. The assessor decides what can be accepted as evidence under the methodology.

How long does the visit take?

Plan for somewhere between 45 and 90 minutes:

• One or two-bedroom flat: roughly 45 minutes to an hour
• Typical three-bedroom house: around an hour to 75 minutes
• Large or extended house: up to 90 minutes, particularly with multiple heating systems, a conservatory or a converted loft

The assessor measures each floor, photographs key items such as the boiler, meters, windows and loft, and records construction details as they go. You do not need to follow them around, although being available for a couple of quick questions speeds things up.

What you don't need to do

Plenty of people stress about an EPC visit unnecessarily. To be clear:

• No cleaning or tidying is required. The assessor is not judging the condition or presentation of your home, and nothing cosmetic affects the rating.
• No repairs are needed beforehand. An EPC is not a survey. A cracked tile or a damp patch is not recorded.
• You do not need to vacate. Tenants, children and pets can carry on as normal, as long as rooms are accessible.
• You do not need to know technical answers. If you do not know what your walls are made of, the assessor works it out from the construction and age of the building.

Day-of checklist

Run through this list on the morning of your appointment:

• Unlock every room, including the garage and any outbuilding attached to the heated space
• Clear access to the loft hatch and have a key ready if it is locked
• Clear the boiler cupboard so the data plate is visible
• Make sure gas and electricity meters are accessible, with keys for communal cupboards
• Lay out installation certificates: insulation, FENSA, building regs, boiler, MCS
• Note the location of your room thermostat and programmer
• Make sure the hot water cylinder, if you have one, can be seen
• Confirm you or your representative will be there to give access
• Secure pets that might object to a stranger with a clipboard and a camera
• Have your booking confirmation and contact number to hand in case of questions

That is it. Ten minutes of preparation is usually all the visit needs.

What happens after the assessment

Once the visit is complete, the assessor enters the data into government-approved RdSAP software, which calculates your rating from A to G. The certificate is then lodged on the official government EPC register, where it stays publicly searchable for its 10-year validity.

L&D Energy lodges your certificate within 72 hours as standard, and sends you the link once it is live on the register. If you are racing to get a property on the market or need to satisfy a letting agent quickly, same-day lodgement is available for an extra £15. Full details of what is included are on our domestic EPC service page, and current prices are listed on our pricing page.

Your EPC also comes with a list of recommended improvements and the rating each one could achieve, which is a useful starting point if you are aiming for a better band before the proposed minimum standards tighten.

Wondering why your certificate does not match a neighbour's, or an older one? That has its own explanation — see why EPC ratings differ between similar homes.

Ready to book, or have a question about an awkward property? Get in touch and we will sort a date that works.