Floor plan single-family house, 2 full floors approx. 180 sqm, 600 sqm plot

Hm... I'm at a loss. I just have to go to the room next door?

You're at a loss because there were no answers directed at you, see the quote.

No, the kitchen is even supposed to be closed at times,

That's what I’m saying. Just not to you, but I was responding to in general.

But optically for the facade, rather in the other direction - the third broom cupboard can be placed somewhere else.

We will actually go through this again with the kitchen planning. However, a refrigerator is placed at the very bottom, so foregoing a tall cabinet of course has to be considered. But maybe the dimensions can be adjusted somehow. It would definitely make sense, although I am actually building more for myself than for the neighbors. But it should definitely look neat!

A support beam would be necessary anyway because of the thick bedroom wall – although offset; however, I recommend a lighter wall up there (or did I already say that?).

No, at least I haven’t noticed that so far. I don’t even know if I can decide so much here myself or if the structural engineering will decide later: According to the static calculation, the interior walls shall be executed with perforated bricks (Poroton) in appropriate thickness or concrete walls. Can you recommend a thickness without calculation at all? Ultimately, that should be seen in the detailed design, right?

But proper it should definitely look!

At the moment it looks right-aligned.

I don't even know if I can decide much myself here, or if the static calculations will decide later: According to static calculation, the execution of the interior walls is done with [...] [...] Can you even recommend a thickness without calculation?

Without calculation, I can say that a heavy wall (considered on its own), which does not have a similar colleague standing beneath it, is a load for the floor slab below (which is lighter accordingly). Whether it (in connection with the question of whether a beam or concrete ceiling lies above) can be slimmer is another matter. If yes, I would go here for 11.5 cm or for gypsum boards (10 cm).