RdSAP 10 collects more detailed data for a more accurate EPC rating. Key changes include:

• Every window is now individually measured and assessed.
• Insulation is recorded by location, type, and thickness.
• Heating systems and renewables are modelled more accurately.
• Ventilation, including extractor fans and flues, is recorded in more depth.
• Air tightness is now part of the modelling, using measured values where available.

Assessments may take slightly longer, but the result better reflects how the property actually performs.