Best Practice Specification – actual U-values exceed best practice

Where the actual building’s thermal fabric performance (U-values) exceeds the BREEAM Best Practice Specification (BPS), resulting in better thermal performance, the BREEAM Best Practice Specification building will need to be modified to match the actual building’s U-values, as stated in Guidance Note 25.

For instance, if the actual building’s roof U-value was 0.10 W/m2K, but the BPS was 0.15 W/m2K, the BPS building will need to be modified to include a roof with a U-value of 0.10 W/m2K.