Construction costs are currently skyrocketing

But you are building, let me guess, a single-family house of over 200 sqm just for your family?!

No, what are you thinking. I am having an old house torn down and building a new one with 145 sqm – for 5 people. The plot wouldn’t even have allowed for two semi-detached houses, and certainly not according to the development plan. I see my acquaintance as a role model, who is building a multi-family house with 4 apartments to address the housing shortage (uh, I mean, of course, his chronic lack of money *g*). I definitely don’t want to criticize your parents. I do wish them well. For me, it’s more about the philosophical side – how must our housing construction thinking be for the future, how do we solve the housing shortage in metropolitan areas, how do we deal with climate issues, limited space and resources, how do we bring people back together, and so on. But now I will keep quiet on the topic, since the thread is about construction costs...

Have you ever heard of a housing shortage? It probably affects sparsely populated, rural areas less; there are also refugees: "Up to 500,000 apartments needed for refugee Ukrainians" (Schlafzimmer 15.03) + the hundreds of thousands who are on the move due to the food crisis in Africa and the Middle East...
It benefits: the climate, the community (which has drifted apart because of Corona), efficiency (shopping or cooking for each other saves time + money, you would always have to rent 2 apartments to friendly couples/families). The GDR showed that cohesion can be lived/practiced in such an apartment building. That would do the German, super individualistic and also selfish society good.

For the Earth, for oneself as a responsible, enlightened (climate education!) person.

Well then, demolish your 140 sqm single-family house with basement in the Stuttgart area and donate the space for an apartment building... apartments are urgently needed there.

Since you are generously providing your land, you can surely insist on greening the roof and raising a flag that says "Single-family house - no thanks."

You keep talking about the waste of sealed surfaces for single-family homes. I believe the goal was 400k apartments p.a.

I am curious how many apartments will be built in the future. On the one hand, requirements are being gradually increased, while craftsmen and materials are scarce and expensive. At the same time, there are always new ideas about rent price caps and levies at the expense of landlords. These problems multiply in connection with already massively increased interest rates into serious problems in residential construction as investment properties. Regardless of whether single-family homes or multi-family apartment buildings. Regardless of whether private investment or capital investment, e.g., a pension insurance.

If the state intervenes further, for example through subsidies, this presumably only shifts the problems into the future!

I am certainly curious about the next few years!

The idea of staying in one's own house until death at an old age seems rather naive to me. I think it would require many many more attractive and diverse options for senior-friendly living arrangements. I know it that way from the USA also from my relatives. People move much more easily when the house no longer suits their life. My great aunts moved in their early 70s. But here, both the infrastructure and the culture are missing to see aging as a new phase of life that one actively plans and shapes, instead of pretending one does not grow old. I am really sometimes afraid of growing old in Germany. I know too many cases where staying in one's own property is not health- or contact-promoting. Especially when a partner dies. And one is no longer able to drive but there is no alternative to a car. I would wish for much more political and social engagement in this direction.

The idea of staying in your own home until death at an old age seems rather naive to me. I think there needs to be many, many more attractive and diverse options for senior-friendly living arrangements. I know it like this from the USA as well from my relatives. People move much more easily when the house no longer suits their life. My great-aunts moved in their early 70s. But here both the infrastructure and the culture are lacking to see old age as a new phase of life that is actively planned and shaped instead of pretending you don’t get old. Sometimes I am really afraid of growing old in Germany. I know too many cases where staying in one’s own property is not health- or contact-promoting. Especially when a partner dies. And you are no longer able to drive but there is no alternative to the car.
I would wish for much more political and social engagement in this direction.

In my residential area, there are three retirees who deliberately built again at 65. 100-120m2 bungalow, 3 rooms, guest WC. Done.
Some have even included an extra room for their future Eastern European private caregiver.
The right approach. I also don’t want to climb stairs later and elevators are rather rare in single-family homes.
Thanks to the real estate boom, this was partly a zero-sum game – selling the old house and building a smaller new one in return.

I was only able to fulfill my dream of having a house very late and with it finally having no stupid people trampling over my head. Surely I won’t move out of here again in 20 years just so that stupid people can trample over my head again.