Single-family house with flat roof and 367 sqm living area

I don't know what it's like to live with an Au Pair,

Imagine a foster child of college age who is useful around the house (unfortunately without that rubbing off on your own brats).

I would have liked to see a real architect's design here without the client's template.

That was also my first thought: that the architect failed to tell the client to put their Pinterest wish list in an envelope and seal it. With money for such a big house, I would never deprive myself of the surprise of what creativity the architect already has.

That's right. But unfortunately only within the building volume according to the requirements of the BH and the building window of 15*16m

oops, yes... 15 meters in depth (probably) I'm not an architect either... but I think that with a perimeter development, garage, and the slope you can get a lot more out of it than a compact house where the stairs are only arranged "left and right." Without a comment from the OP, you don't have to strain your brain on a Sunday ;)

I want to bring up a sensitive topic: I just realized that the (also male) overnight guests are probably supposed to use the Aupair’s bathroom. They use the bathroom at night and right next to it the girl (?) is lying in bed. I’m sorry, but as a woman I find that unacceptable. Even if the overnight guests are beyond any doubt, I think it is a living situation that neither I nor an Aupair would expose ourselves to. You as builders are familiar with the overnight guests, the Aupair is not.

you are exaggerating a bit. Au pairs are adults. They are usually treated like grown-up children. They should be able to get along with a guest of the house.

Besides, there are keys for the door in case the au pair needs them, as you can see.

I don't understand anyway why the au pair should live 2 floors away from the children.

They should be able to get along with a guest of the house.

But not with someone who uses her bathroom, she is right about that.

Without a comment from the OP, you don't really have to fire up your brain on a Sunday ;)

He probably didn't expect so many suggestions for improvement. It's not that easy to respond to that. But when even simple follow-up questions remain unanswered, I have a feeling about why the thread was started.