[CMOTD]

This is not a post about the merits of the climate change debate, regardless of which side you are on and I am not trying to start any political trouble. 
It is just a simple question really - the government is/was making various rules about EVs, phasing out gas boilers, compulsory heat pumps etc. So why on earth haven't they made the fitting of solar panels on every new building, commercial and domestic, a compulsory part of obtaining planning permission? It would add a very small percentage to the astronomical cost of the average new build, everybody would get some free electricity and, if you believe in such things, would massively help save the planet.