Before the visit
Preparing for your EPC assessment
A short checklist so the survey takes 45–60 minutes and nothing needs a second visit. Nothing here is difficult — it is mostly about access.
Before your appointment
Please read before your EPC
These points help the assessment run smoothly, and explain how quotes and EPC ratings work.
What to prepare
- Access to all rooms, radiators, windows, heating and hot-water systems.
- Supporting documents: if insulation or another improvement is hidden and I cannot access, measure and photograph it, please provide legitimate documentation showing what was installed — including the insulation thickness where applicable. Without suitable evidence I cannot assume hidden insulation is present, and the approved methodology requires the applicable RdSAP default to be used instead. Window installation details, hot-water-cylinder information, heat-pump flow-temperature information and solar or MCS documents may also be useful.
Important notes
Turnaround
The turnaround time for the EPC certificate after the assessment is within 72 hrs.
Pricing
Your quote is based on the property details provided and assumes a standard property. If the property has a substantially more complex layout, significant extensions or other material features that were not discussed beforehand, any necessary price adjustment will be explained and agreed before the assessment begins.
More about quotes and property complexityRatings
I cannot manually adjust or influence your EPC rating. I collect and record the property data and any acceptable supporting evidence. The score itself is calculated by approved EPC software using the government-approved methodology.
How your EPC rating is calculatedOlder or neighbouring EPCs
Existing homes have been assessed using RdSAP 10 since June 2025. It is an updated, more detailed methodology, so a new EPC should not be expected to reproduce a pre-June-2025 certificate exactly. This does not mean an older certificate was wrong, and the update does not always raise or lower a score.
Ratings can also differ between neighbouring properties — because of whether a home is mid-terrace or end-terrace, insulation, glazing, extensions, heating systems, floor area and the evidence available during the assessment. Two homes that look alike can legitimately score differently. Concealed insulation, in particular, may not be recordable without evidence the assessor can accept.
Why your EPC may differ
All rooms
Including the loft hatch, any outbuildings and locked or storage rooms.
Heating systems
Boiler, cylinder and controls — plus the manual or model number if you have it.
All windows
Every window and external door, so glazing type and age can be recorded.
All radiators
Clear enough access to see each one, including behind furniture or curtains.
All lights
Fittings need to be visible so low-energy versus halogen can be counted.
Electricity meters
Including the meter cupboard key if it’s a communal or external box.
Tenanted property? Please arrange the visit with your tenants and give them proper notice — they’ll need to let us in and have the rooms accessible. If that’s difficult, send us their contact details and we’ll sort it out with them. Evening and weekend slots are available at no extra cost.
More than one property? If you own several in the same area, they can be grouped into a single visit rather than booked one at a time — quicker for you, and it usually means a discount. Tell us the postcodes when you enquire and we’ll quote the whole set together.
Documents and evidence that may help
An EPC is based on what the assessor can verify during the visit, together with supporting evidence they can accept. This matters most for concealed insulation — behind walls or floors, under boarded lofts, in extensions or doors. If it cannot be safely accessed, measured and photographed, it can only be recorded where documentation confirms what was installed, including the insulation thickness where the methodology requires it. Otherwise the applicable default or age-based assumption has to be used.
Windows and doors
- Installation certificates
- Invoices from the installer
- Anything showing the installation date or the specification fitted
Insulation and building fabric
- Loft, wall or floor insulation records showing what was installed
- Building-control or construction paperwork for an extension
- Insulation specification or thickness — the detail the methodology needs
- Documentation for insulated doors, where relevant
Heating and hot water
- Boiler make and model — a photo of the data plate is usually enough
- Boiler installation or service paperwork
- Hot-water cylinder details, including insulation type and thickness
- Heat-pump installation or commissioning documents
- Design or flow-temperature information, where it is available
Solar and renewables
- MCS documentation, where you have it
- Commissioning or installation paperwork
- System specifications, such as panel capacity or inverter details
None of this is compulsory
You do not need any of these documents to have an EPC carried out, and no single document is required. They are simply the things that sometimes help, where they exist and where the assessor can accept them as evidence under the assessment methodology.
Why evidence matters
An assessor cannot simply accept that concealed insulation exists. Where it cannot be safely accessed, measured and photographed, documentary evidence is needed — and it has to carry enough detail to establish what was actually installed, including the insulation thickness where the methodology requires it. Without that, the approved methodology requires a default or age-based assumption instead, which can be less favourable than what is genuinely there. The assessor is also responsible for validating the information used, which is why a verbal assurance on the day is not enough on its own.
It is worth being precise about what that means: evidence changes what can legitimately be recorded, not what the rating will be. Bringing paperwork does not guarantee a better result — it just means a genuine improvement is less likely to go uncredited. Read the full preparation and evidence guide.
What happens on the day
Your assessor photographs and measures each room, records the heating system, insulation, glazing and lighting, and reads the meters. There is no testing, no mess and nothing invasive. Once the survey is done, your certificate is lodged on the official GOV.UK EPC register within 72 hours, or the next day if you chose express, and we send you the link as soon as it is live.
Things worth knowing before your EPC
Your quote is based on the details you give us
We price from the property information supplied before the appointment. If the property is materially larger or more complex than described — a significant undisclosed extension, a loft conversion that was not mentioned, or an unusually complex layout — we will explain any adjustment and confirm it with you before the assessment starts. You will not find a different number on the invoice afterwards. In practice this is rare; most quotes stand exactly as given.
Your EPC rating is not chosen by the assessor
This is the question we are asked most, so it is worth being direct. Our role is to survey the property, record its physical characteristics and systems, verify what evidence we can accept, and enter that data. The rating is then calculated from that data by the government-approved methodology and software.
No assessor can raise or lower a score to reach a requested result. If we could, the certificate would be worth nothing to the buyer, tenant or lender relying on it. What we can do is make sure everything genuinely present is recorded and evidenced — which is what the evidence section above is for.
Why your EPC may differ from a neighbour’s or an older certificate
EPC ratings are specific to the individual property. Two neighbouring homes can receive different ratings even when they look almost identical from the street. Things that legitimately change the result include:
- Position in the terrace — a mid-terrace home has fewer exposed walls than an end-terrace or semi
- Floor area, extensions and layout
- Wall, roof and floor construction and insulation
- Loft insulation depth, and whether it can actually be inspected
- Window and glazing age and specification
- Boiler, heating controls and hot-water cylinder
- Heat pumps, solar PV or other renewable systems
- Lighting
- Extensions or loft conversions built at different times
- The evidence available on the day
- The methodology used to calculate the certificate
- The information recorded during the previous assessment
The methodology changed in June 2025: RdSAP 10
Existing homes have been assessed under the updated RdSAP 10 methodology since 15 June 2025, replacing the approach used for older EPCs. RdSAP is a reduced-data version of the full SAP calculation, used for existing homes because the complete construction data a new-build assessment relies on is rarely available for a property already standing.
Older and newer EPCs may differ because the methodology, the data requirements, the property evidence and the technologies considered have all evolved. That is a change in how a home is assessed and recorded — not a judgement that older homes or older building standards are now “bad”, and not a requirement to modernise anything.
Because of this, a new EPC should not be expected to reproduce an older certificate exactly, even if the property itself has not changed very much. An older EPC reflects the methodology and information available at the time; a current EPC assesses the property using today’s approved methodology.
This does not mean an older EPC was automatically wrong, or that RdSAP 10 will always produce a higher or lower rating. The result depends on the individual property, the features present, the evidence available and the methodology used. RdSAP 10 remains the approved methodology for existing dwellings in England and Wales under the current GOV.UK notice of approval.
Previous EPCs can also contain different assumptions or recorded information. If an older certificate looks inconsistent with the property, it is worth comparing the underlying property details rather than the letter rating alone — and genuine errors are possible, though they should not be presumed.
Comparing EPCs? Compare the property details and the assessment methodology — not just the letter rating.
Official guidance on energy certificates is published at GOV.UK. For the longer explanation, see why EPC ratings differ between similar homes.
Ready to book your assessment?
Send us the property details and we'll confirm your exact quote and a time slot.