Consequences of the coalition agreement for home builders?

I was actually thinking more about fully charging the car during the day with the photovoltaic system to use it as storage at night.

That would be the “summer operation” with the surpluses from the photovoltaic system. In winter, you charge when the electricity is cheap and then use it in the house when the vehicle doesn’t need the full energy and is just parked anyway.

I was actually thinking more about fully charging the car during the day with the photovoltaic system

Most cars are probably not at home during the day but on the road.

During the day most cars are probably not at home, but on the road.

Not on weekends. Then I prefer to enjoy my garden when the time comes.

In the end, it will become massively more expensive for both renovators and new builders in terms of investment costs, without this being reflected in correspondingly lower operating costs. All the insulation is also ecologically extremely questionable given the energy required to produce the material, but no one wants to hear that.

Doesn't that depend significantly on the insulation material used?

Sure, only the truly effective insulation materials are not really environmentally friendly, no matter how you look at it. Otherwise, yes, you can also insulate with concrete. But that is not more environmentally friendly either.

During the day, most cars are probably not at home, but on the road.

Many are at home, many on company parking lots, many in cities, some are even being driven...
Even if only 30% of the vehicles are considered suitable for meaningful bidirectional charging, that is a significant amount.
There is no single solution for every situation, so situations are always conceivable in which a fundamentally good solution does not work.
The absurdity becomes clear perhaps with an example:
"There is now a new headache pill that works stronger and is better tolerated,"
"but most have digestive problems instead."