Question to the Department for Energy Security & Net Zero:

To ask the Secretary of State for Energy Security and Net Zero, what estimate his Department has made of the proportion of (a) external and (b) internal insulation installations completed under Government energy efficiency schemes that require remediation in Surrey Heath constituency.

The Government commissioned an independent statistical audit, however this sample was designed to estimate the overall rates of non-compliance across Great Britain. The samples are not large enough to reliably perform any regional analysis. As we continue with further audits, we will seek to begin to collect this data.

The statistical audit was commissioned by Ofgem in April 2025. Two random samples of audits of external (EWI) and internal wall installations (IWI), across the household populations of both schemes were commissioned to understand non‑compliance rates.

98% of EWI audits need to be remediated. For IWI, that number is 29%.