OK, now the argument makes more sense.

Some bodies came up with requiring newly built housing to have planned in a renewable energy source. The idea is that those who build are investing into the future already and gathered large amounts of capital anyway. The disadvantage is the creation of a mid-term disincentive for housing construction, so keeping the housing supply in control might be more crucial. This method is also slow.

Solar is expensive.

Please explain. PV is cheap AF.