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 number of homes affected by defective insulation installed under government schemes between 2013 and 2021; and if he will commission a national audit of all such properties.

Data has not been collected regarding the specific number of houses affected by non-compliance, however failure rates from audits of individual measures has been collected for some schemes of which a summary is included in the NAO report.

For SWI installed under ECO4 and GBIS we have calculated the number of homes affected. We acknowledge that issues have emerged in other schemes, however this is not on the scale seen with EWI issues under ECO4 / GBIS. We have recent published results from audits on our housing association and local authority based schemes on gov.uk.