The weird thing is, the Tories kind of tried this but bungled it so badly it would be too politically toxic to try again for a while. They had the ECO4 scheme for free and discounted cavity and solid wall insulation, but no requirements for the companies providing the insulation to be certified or deemed reputable. So a lot of cowboy companies sprung up to take advantage of the free money, installed it poorly, and now the horror stories on social media scare people off cavity wall insulation and external wall cladding entirely.

We had this devolved in Northern Ireland rather than taking part in the GB scheme, and in a very rare case of our assembly being competent you can only get the grant through specific companies that have been vetted in advance.