High construction costs with rising building interest rates

I don’t agree with the other point. A reasonably young house has good insulation standards. These are sufficient for radiators to achieve a flow temperature suitable for a heat pump.
In older houses, you can if necessary assist with fans under the radiators. The top floor ceiling, the basement ceiling, and some other small things are often enough to significantly reduce heat losses.
Turning an old house into a new one really makes no sense at all, as it is far too expensive. But raising the house to a standard that won’t financially drain you in the future is definitely possible at an acceptable price.

Why should that make no sense? You would leave the building skeleton, which at least saves valuable resources and is therefore more reasonable than a complete new build. But you can’t live forever with old electrical installations (also legally, if changes are mandatory at some point), and then it eventually doesn’t help much if you only replace the old carpet to improve the look. That’s when you reach a core renovation, and unfortunately that is often a financial loss.

What is a reasonably young house? Let’s try a simple logic: We have a house with small radiators operated at a flow temperature of 60 degrees. That is no problem for a gas heating system. But for the heat pump it is, because it is more efficient at lower temperatures. Now you really want to operate a heat pump efficiently and therefore go down to 35 degrees. Where should the heat come from then with 25 degrees less? Until now, 60 degrees were needed, since the radiator size was designed for that. You cannot compensate for that with less night setback, turning up all radiators fully, etc. at all. You can at most reduce the room temperature, but that significantly lowers comfort. That is your choice then. No, I would go for underfloor heating. There you also get more comfort from the renovation at least. Insulating the building envelope to keep the old radiators costs too much in proportion to the savings potential and doesn’t really offer more comfort. You can do that if the facade is already in a terrible state anyway. For the basement and roof, I can understand it better. But the latter is only done when the roof has to be replaced anyway.

1. this is nowhere stated 2. this is also not true Where do you get the assumption that (young) families cannot afford a house? That brings us back to the problem that young families want to fulfill their dream house of 160sqm plus including a double garage already in their mid-20s. You just don't have to have everything big and fast immediately without personal contribution.

I have nothing against personal contributions if you want to make a fair comparison to the past. But even with personal contributions, in many regions you are in the realm of the impossible. In the metropolis, it costs you a million, which even two high earners without family support can no longer shoulder. And even in the countryside, where it might "only" cost 500 thousand, it is hardly feasible with 5k net income without significant equity. Once children arrive, it doesn't remain at 5k net income, but the income usually falls and not only temporarily.

A fair comparison also includes the fact that people in the past built their houses themselves because no one looked closely and the legal framework was much more lenient. Nowadays, illegal work is more difficult (if only because you first have to know these people) and even personal contributions are limited to fewer areas for legal and liability reasons.

Yes, today's youth could save more (less vacation, fewer restaurant visits) and start working earlier (shorter / no studies enable faster buildup of equity). Still, it is fair to acknowledge that affordability has deteriorated significantly in the past 10 years. In my social environment, only those with family support (old property to renovate or equity for external purchase) really stand a chance.

Capital accumulation was also made more difficult due to 0% interest rates.

Also an important point: the number of children. In my youth, families with three children (probably not in the big city, but in my environment yes) were still absolutely common, only children the rare exception. A family of five needs a bit more space and of course 160m2 would be comfortable, but not a luxury. Especially without a basement, which was still common 30-40 years ago.

I can easily believe that a small house without a basement is still somehow possible for a one-child family somewhere in the sticks. Extensive work can also be done there more quickly again. But what about the three-child family that we as a society (my personal view) need? Should only those on Bürgergeld do that anymore, because financially it doesn't make a difference anyway? Of course, it affects a society when despite hard work you can’t build anything up anymore and at least in terms of living conditions have to live like those on Bürgergeld.

Yes, that is somewhat generalized. But it describes the picture quite well. Those who have family support can still escape it. But earning something just through hard work has become very difficult.

By the way, a fair comparison also includes the fact that people used to build their own houses partly because no one looked too closely and the legal framework was much more lenient. Nowadays, undeclared work is more difficult (not least because you first have to know these people), and even self-performed work is legally and liability-wise restricted to fewer and fewer areas.

What kind of arguments are these? You can do everything yourself on your own, so what liability reasons could there be? The only thing that comes to mind spontaneously is the meter cabinet, which has to be approved by the electrician. Otherwise, you can do whatever you want (speaking from experience). In the past, you probably had to know the undeclared workers too. I don't think the Yellow Pages existed for that 30 years ago either. I have now completed two construction projects (an extension and conversion/renovation of an existing house, new construction of a two-family house). I myself am not from the construction industry (after high school, I trained as an industrial electrician, then studied math/physics, and have been working as a high school teacher for 10 years) and have still contributed a lot of self-performance and organized everything myself. Of course, during the construction phases, I also have no time for hobbies and the family has to make sacrifices. I often think it nowadays fails because of the willingness to endure hardship and determination.

What kind of arguments are those? You can do everything yourself on your own, so what reasons for liability could there be? The only thing that comes to mind spontaneously is the meter cabinet, which has to be approved by the electrician. Otherwise, you can do whatever you want (speaking from experience). You probably had to know about the illegal workers back in the day as well. I don't think there were any yellow pages for that 30 years ago either. I have now completed two construction projects (extension and renovation/refurbishment of an existing house, new construction of a two-family house). I myself am not from the construction industry (after high school, training as an industrial electrician, then studied math/physics, and have been working as a high school teacher for 10 years) and still did a lot of work myself and organized everything myself. Of course, during the construction phases I had no time for hobbies and the family also had to make sacrifices. I often think that nowadays it fails due to lack of willingness to endure and lack of determination.

You definitely connect the photovoltaic system yourself as well. Oh yes, you just remove the asbestos during the renovation and take it to the nearest recycling center. Occupational safety used to be much stricter. So were building regulations. Just quickly erecting an exterior wall with thin stone wasn’t possible in the ’60s. Caution: Irony. And yes: you had to know friends among craftsmen back then too. But that was the rule because the density of craftsmen was much higher (and you could do more yourself on the side) and you stayed in the home village with an intact social network. That is now missing especially from those who move to the big city for the job. The further you go out into the countryside, the more it still works today.