Construction costs are currently skyrocketing

Maybe making the plans for energy-efficient renovation of old buildings mandatory isn't so bad after all...

And what if someone can't afford it? They then have to sell at a forced bargain price and have to find a small apartment within 6 months?

And if someone can’t pay? They then have to sell at a forced bargain price and have to find a small apartment within 6 months?

mimimi ... Normally, I would fully agree with you and immediately call for social justice. But the alternative—continuing as before and letting the next (last?) generation go under? No, I’d rather let some injustice pour down on the population with a one-size-fits-all approach. And you still set the selling price yourself, right? Or does the market do that? So it DOES NOT have to be a bargain. Alternatively, the state intervenes again with subsidies after mandated renovation, which I see here as rather likely in combination.

the state intervenes again with benefits after mandated restructuring

And the entrepreneurs do not know this and do not increase by this factor ^^

And the entrepreneurs don’t know that and don’t raise prices by this factor ^^

Well, always these evil entrepreneurs! Get involved politically at last, change Germany in your desired direction, but don’t keep whining or scolding those who take what they can (because the current political and social system allows it). I really can’t listen to it anymore... Or alternatively become an entrepreneur yourself and make use of the system. But feeling comfortable in the victim role? That can’t be it – can it?

I don't renovate ;) so I don't really care what rules are set here... I just see the risk, especially for older or low-income families, of losing the house...

I don’t renovate ;) so I really don’t care what rules are set here... I only see the danger, especially for older or low-income families, of losing the house...

I also don’t think a requirement upon possession is good, but renovating to a KfW standard when selling wouldn’t be wrong at all. I have a case in my colleague circle. Huge house 340m2 living space from the 70s bought cheaply in 2012 and now he’s wondering about the heating costs. If he had done the facade back then and got rid of the oil heating, he could be happy now, but now he has to do it even though it’s currently inhabited.