Question to the Department for Business, Energy and Industrial Strategy:

To ask the Secretary of State for Business, Energy and Industrial Strategy, what proportion of those homes with cavity walls which did not have insulation installed on 31 December 2021 have been insulated since that date.

BEIS estimates that there were 6.2 million homes in Great Britain with cavity walls that were not insulated at the end of December 2021. In the first seven months of 2022, it is estimated that around 31,000 (0.5%) wall cavities were filled, supported through the Energy Company Obligation (covering Great Britain) and Green Homes Grant government schemes (covering England only):

https://www.gov.uk/government/statistics/household-energy-efficiency-statistics-detailed-report-2021.