Single-family house floor plan - narrower possible? First ideas

I don't know, somehow I really don't like the upper floor. It's all strangely pieced together... Unfortunately, I also can't tell you right now what I would change, because I already don't like the basic layout of the rooms. I would roughly put the master bedroom where the bathrooms are now and turn the current master bedroom into a small bathroom. Just scribbled here, the red area for the children and the whole green area for you, that’s how I would basically divide it. That would be over 30 sqm for dressing, bathroom, and sleeping for you – surely something could be made out of that.

but then I have the problem with the long lines for the children's bathroom. Isn't that suboptimal and expensive?

This is roughly the direction I would look in... I can't tell you how expensive something like this would be.

You could also google the Variant 25-150 Hanse Haus, that might at least fit well for the upper floor? Maybe the ground floor would work too?

So I quite like it this way. My only concern would be that your bed is right next to a children's room. Personally, I wouldn’t find that very cool either as a child or as a parent. A dressing room or the bathroom in between would definitely be better soundwise. Otherwise, I think it’s great as it is.

Ah, and the sink probably doesn’t fit there. See if you can arrange it differently—maybe find a niche for the toilet, it shouldn’t be the first thing you see when you come in.

And the staircase might be a bit tight on measurements. We also decided on a landing staircase and I would plan for at least 225x270. But otherwise, I think it’s great as it is.

By the way, our dimensions are quite similar.

1:25 One box is 25 cm

... and that is 1:50

we discarded a straight staircase because it never fit. I decided on a landing staircase for the floor plan.

For the architect meeting, you better prepare "only" with a list of rooms and wishes, or vary based on proven typical floor plans. Your sense for functional dimensions is not sufficient for creative floor plan design (or at least not under the additionally restrictive condition of the targeted house width or rather narrowness). You drew symbolically a two-flight straight staircase - but in terms of space it corresponds to a U-shaped staircase.