The assessor spends 45 to 90 minutes at your property, depending on size and complexity. They’ll measure windows and doors, calculate floor area and heat loss, check party walls, and access the roof space to assess your home’s fabric and insulation.

Heating, ventilation, hot water, and any renewables are examined too, along with fuel types and controls like thermostats. Under RdSAP 10 the data collection is more thorough than before. It’s non-invasive, no drilling or moving furniture, but the assessor needs access to every room, the loft, boiler, and meters. If insulation or another feature can’t be physically evidenced, it may not make it into the report, so have any documentation ready.

You don’t need to be present, but being available to answer questions helps. Read more about preparing for your visit.