An assessor will inspect your existing home:

• The inspection takes 1-1.5 hours and looks at:
• Property – Age, size, extensions and conservatories.
• Roofs, Walls, Windows and Floors –To determine the level of insulation and heat loss.
• Ventilation – Controlled ventilation (like heat recovery systems) and loss through draughts (like open chimneys).
• Heating Systems – Age, type and efficiency of boilers, heat pumps and water heaters.
• Lighting – Measuring the efficiency of lighting (LED v old style high energy bulbs).
• New Technologies – Smart meters, heat pumps, solar, wind and small scale hydro. 

The methodology used to assess existing domestic properties was created in 2005 and is called Reduced Data Standard Assessment Procedure (RdSAP). The standard continues to be updated, from 15th June 2025 the version used is 10.2. This is set by the Government.