@david_chisnall The EU is doing this somewhat, with the revision of the #EnergyEfficiency directive for buildings passed ion 2024, but with a much longer timescale. The financing part is handled by the EIB.
https://energy.ec.europa.eu/topics/energy-efficiency/energy-efficient-buildings/energy-performance-buildings-directive_en
The opposition, which managed to water down many provisions, occasionally had good points, so you can look at that debate to refine your proposal. :)