Question to the Department for Energy Security & Net Zero:

To ask His Majesty's Government what assessment they have made of the benefits for (1) retrofit spending, (2) quality assurance, and (3) energy models, of including u-values in the Reduced Data Standard Assessment Procedure, the Home Energy Model, and the Standard Assessment Procedure.

U‑values can be measured on-site or taken from defaults. Using measured U‑values reduces reliance on assumptions and can provide a more accurate view of real building performance. For new buildings, the Standard Assessment Procedure (SAP) and the Home Energy Model (HEM) require U‑values to be provided.

For existing buildings, Reduced Data SAP does not require measured values because in‑situ data is harder to obtain, though defaults can be overridden where verified evidence is available to assessors. Government is consulting on HEM for existing buildings, including exploring the optional use of additional verified, tested U‑value evidence to improve assessment accuracy.