Question to the Department for Energy Security & Net Zero:

To ask the Secretary of State for Energy Security and Net Zero, with reference to the National Audit Office Report entitled Energy efficiency installations under the Energy Company Obligation, published on 14 October 2025, what the cost to the public purse is of remediating defective retrofit work carried out under the Energy Company Obligation scheme in Wales.

The remediation costs sit with the original installer and we have been clear that no household should be asked to pay any money to put things right. We expect most remediation for solid wall insulation installed under ECO4 or GBIS to cost between £250 and £6,000 for IWI and £5,000 and £18,000 for EWI. This should be covered by the guarantee should the installer no longer be trading.