UK:
"The guidance published on Tuesday means that from 2028, no new homes will be on the gas network - and will instead be on a heat network or get a heat pump - and they must have solar panels on their roofs covering an area equivalent to 40% of the ground floor space.
It also said plug-in panels that homeowners can self-install on balconies would be available in supermarkets in the coming months."
https://www.bbc.com/news/articles/czjw7klkjm2o