An EPC assessment is a straightforward site visit followed by a calculation. Most Edinburgh homes take between 30 and 60 minutes on site, and larger properties a little longer. Here is the whole journey.
Step 1
Before
- Make the rooms that make up the property accessible.
- Where applicable, make sure the loft hatch can be reached safely.
- Gather any paperwork for features that cannot be seen — insulation, glazing or heating upgrades.
Step 2
During
- A non-invasive survey — nothing is opened up, drilled or damaged.
- Dimensions, glazing, construction, insulation, heating, controls and hot water are recorded.
- Photographs and site notes are taken as evidence for the assessment record.
Step 3
After
- The data is entered into approved RdSAP software, which calculates the rating.
- Your EPC and recommendation report are produced and lodged to the Scottish EPC register.
- Watt EPC aims to lodge within 24 hours of the visit.
Before the visit
The assessment covers the whole dwelling, so the rooms that make up the property need to be accessible — including the loft where the property has one and it can be reached safely. Documentary evidence is genuinely useful for anything that cannot be verified visually, such as insulation hidden behind finishes or a glazing upgrade.
The full list is in our preparation guide.
During the visit
The survey is non-invasive. Nothing is drilled, opened up or removed — the assessor records what can be observed, measured and evidenced, and takes photographs and site notes for the assessment record.
Dimensions
Room, floor and external dimensions, storeys and floor levels.
Construction
Wall, floor and roof construction and property age band.
Insulation
Loft, wall and other insulation where visible or evidenced.
Glazing
Window types, glazing and, under RdSAP 10, window measurements.
Heating
Main and secondary heating, fuel type and efficiency data.
Controls
Thermostats, programmers and heating control arrangements.
Hot water
Hot water source, cylinders and any insulation to them.
Technologies
Relevant technologies such as solar PV, batteries or heat pumps.
Evidence
Photographs and documentary evidence supporting the record.
Floor plans are measured room by room, along with external dimensions, so the software can model the heat loss surface of the property correctly.
After the visit
The collected data is entered into approved RdSAP software. The software — not the assessor — calculates the rating and generates the recommendation report. The certificate is then lodged to the Scottish EPC register, and Watt EPC aims to lodge within 24 hours of the visit.
Once lodged, you receive your certificate and can read how to interpret the recommendations. If the rating differs from a neighbour's, the neighbour comparison guide explains why.