Build or buy a house? Children already 13/15 years old...

We have also built and do not want children, as these pests do not suit us, so to speak, and we prefer to live without them. Have a cat, that is enough.

Would therefore not make it dependent on that, but on many other criteria ...

Exactly bungalow or at most a condominium with a garden. House without children, what's the point

You don't build just for the children.
Why shouldn't you be able to enjoy the house, yard, and garden yourself? Children's rooms can be well used as hobby rooms or sports rooms.
You can use your own home with grown children, whether you are 35 or 50... nobody knows you. Or is your life over when the children go their own ways?
What can you build on the building plot? Is the location good?

House without children, what for

Is the question meant seriously?

We also don’t have children (I didn’t want any) and still have a house. Children are definitely not missing here, the extra space is already being used, and our house is not exactly small (180 sqm plus ancillary areas). Office and gym room and TV room, and suddenly the place is full. But I wouldn’t build the classic “master bedroom and 2 kids’ rooms upstairs” layout, rather I’d plan it right away as you would imagine it without children. Then the “dear little ones” have to adapt to the house in the last few years, not the other way around. But well, who can really look into the future. My sister-in-law didn’t manage to move out of her parents’ house by 40 either. My sister also depended on mother daily in the 2-room apartment until her death (well over 40).

I do think that it is still worthwhile. The trend among young people is to stay longer in the "hotel mama," especially in regions with high rents. Even the first salary after training is often no longer enough for one's own place. Moving out only at 25 or 26 is then not uncommon.

Is the question serious?

It was not a question but a statement. Their children are already about to leave. So why a house then? I observe here more and more houses being sold when children grow up. But you can open Hotel Mama ...