Single-family house with a hip roof, approximately 340 sqm

Feel free to leave your feedback when you are done.

I think that was already the essential feedback. The draft has very unusual proportions: alternating narrow spots and very generous areas. Tell me a bit about the way the design was created: was there a template that was simply blown up in overall size without any sense of dimensions (and why even the latter: a surprising lottery win?)?

So...I have now drawn the 2-meter lines. I hope that is correct as a continuous line.

So, now draw in how you imagine the bed in the bedroom upstairs ;) ... EDIT: and write down how tall you are.

Solid construction: Poroton inside, brick outside

Poroton = brick ;) Did you perhaps mean aerated concrete? (I hope not.)

Poroton = brick ;) Did you perhaps mean aerated concrete? (I hope not.)

No aerated concrete. ;)
Inside: Poroton
Outside: solid brick

So you are talking about the outer masonry shell? Then it's best to say it that way right away. ;) (Because I had interpreted it as you were talking about interior and exterior walls, not about the inner and outer wall shells (of the exterior walls).