Construction costs are currently skyrocketing

I assume that the densification in cities, with the usually associated consequences, will not have a positive effect on the children and adolescents growing up there.

It depends on how you implement it. If you just dump a bunch of high-rise buildings with hundreds of apartments somewhere where everyone looks into each other's balconies and between them is a janitor's garden (grass and a few boxwoods), then you're creating the next social hotspots. But it can also be designed better if you want, with smaller houses and real places to stay. You don't necessarily have to raise children in a single-family house with a garden, and in many areas that is not practical either. Of course, it's convenient for parents if the children can stay on the property and you don't have to go to the playground. But it is not really necessary. And a single-family house on a 400 sqm plot doesn't really have a garden that deserves that name anymore; it's more of a buffer strip. PS: Don't older people need a somewhat safe environment? ;)

At the beginning of 2022, concluded at the Sparkasse at 1.1% for 20 years. As of now, over 1000€ more in installments, that would not be possible

Unfortunately, these are exactly the groups of people who, in my personal opinion, even if we ourselves belong to them, "need" a single-family house with a garden the least, and for whom it would be, I repeat, my personal opinion, most important that they (the children and adolescents) grow up in a safe and reasonably orderly living environment with social visibility.

Why don't you make your house available to a family with children, regardless of rent or purchase? All this still at an affordable price for the 4 or 5-person family? You can see, I don't share your view. After 45 years of work, am I supposed to live in an apartment? Maybe in 15 or 20 years, depending on my health condition.

After 45 years of work am I supposed to move into an apartment?

One could also say: Now it doesn’t matter anyway :p Just kidding, Pinki wrote "need". Do you need 5 - 7 rooms then?

But will it really be cheaper for the average home builder if you also expect rising interest rates? If the house is 50k cheaper next year, but the interest rates are above 4 percent, I haven't gained anything either, unless I bring a lot of equity.

Yes, you will need more equity. In my opinion, that's not a bad thing. The "oh, the municipality has a new building area, let's apply spontaneously" is over. More supply for those who have been consistently saving for years with the goal of building/buying a house and not starting with "equity" of 30k. Everything is normalizing again a bit.

I keep wondering how people can make such statements in this tone when they apparently have had no idea about the topic for the past 2 years. Sorry, inform yourself first then write!!!