Plan for the Future Today

I live in Congleton in Cheshire. Every where I look builders are putting up new houses. If everyone is truly concerned about rising temperatures and using clean electricity then why is it not mandatory for new build houses to have solar panels? If all the houses in the UK need to convert it is going to take some doing. At what cost? To whom? Make it mandatory and expected that all new houses come with electric hobs and ovens and solar panels, in the same way they come with running water. Why wait till later? People will still buy houses and the cost would be in bulk for the builder so not too costly to add onto the price. Let's do something with planners and builders today.