Single-family house with staggered floor, southwest location in Bonn

A "normal" grand piano already measures about 160x160, without the bench and free space around it. However, it would have the advantage that when guests come, you could also place the hot dumplings or the beer keg there.

If you want to order the Stimmer afterwards, yes. By the way, a grand piano is also an acoustic diva – just as a side note to the idea of a 4 sqm viewing hole for the perceived connection between the two floors:

I am rather thinking about whether one could create a visual connection between the upper and lower floors by simply leaving a roughly 2x2 corner free where the dressing room is now.

You could also consider changing the direction of the stairs, then the ground floor can remain as it is and upstairs could look like this. You would have a great bright and spacious dressing room where you can also do some ironing. And the hallway is not quite so cramped...

No, not at all pretentious. So, it’s a small baby grand piano and therefore not that big. The table and corner sofa have so far actually only been entered as placeholders. In general, the idea to at least make more concrete considerations about the size and placement of the furniture on the ground floor is good. Also in the kitchen. On the other hand, we still have quite a lot of freedom to adapt to the room and with the size, quite a lot is possible.

What do you mean by conveying the entrance to the central dining table? I imagine the dining table rather positioned diagonally, precisely so that it fits with the piano. We are planning more with an L sofa and an additional armchair/chair.

In my opinion, many only evaluate the floor plan and of course question everything due to a lack of background information, without knowing the further surroundings. That is okay too, but it feels like none of my explanations are accepted or even taken in any way.
The garage, for example, does not make sense anywhere else on the property because it is located at the north end of the plot and the street runs there. Otherwise, I would have to put the garage in the garden. This btw also results in the entrance and the stairs. Moving the stairs to the north hardly benefits my space planning and would also not create a visual connection to downstairs.

If I could, I would also rather build only 210-220 sqm and save downstairs, but the 100 sqm upstairs, which result from our requirements (2 children's rooms, children's bathroom, parent areas (bathroom, dressing room, bedroom)), unfortunately require 150 sqm on the ground floor because of the stepped floor and 66% according to the old building regulations. That is why, for example, the somewhat oversized "all-purpose room" and the satellite kitchen.

The hallway would gain through my suggestion with the lens as a connection between upper and ground floor and be somewhat brighter and more spacious, also to the corridor to the study/guest room.
If working were really just working and not rather guest, I would appreciate the suggestion to connect it through the living room. Even if I make the bathroom bigger, it would then have to be a pass-through bathroom to the guest room. I find that somehow strange. Through the lens, the dressing room would become smaller and only a passage room to the master bathroom, and the bedroom only accessible through the bathroom. Does anyone else have that? 4m of cabinets and a sideboard would probably suffice.

I would be willing to make the living room a bit smaller for a bit more hallway, but then the problem between living room and kitchen would become even worse. And the desire for a separate kitchen simply remains. We have it like this now and find it good. I’ll reconsider the question of whether you immediately see into the living room from the entrance. On the other hand, the house is on a private street and the door can also be closed.

By the way, I’d be happy to be convinced by other floor plans if you have them :)

If you want to order the tuner afterwards, yes. By the way, a grand piano is also an acoustic diva - just by the way regarding the idea of a 4 sqm viewing hole for the perceived connection of the two floors:

What just by the way regarding the idea of a viewing hole?

You could also consider changing the direction of the stairs, then the ground floor can stay as it is and upstairs it could look like this. You would have a great bright and spacious dressing room where you can also iron from time to time. And the hallway is not quite as convoluted...

That would have something to it, hmm.

The garage, for example, otherwise makes no sense anywhere on the property,

Yes. When I look at the entire property (and remember my statements from quite early in the topic), I see a shared underground garage as almost inevitable.

If I could, I would also prefer to build only 210-220 sqm and save downstairs, but the 100 sqm upstairs resulting from our requirements (2 children's rooms, children's bathroom, parent areas (bath, dressing room, bedroom)) unfortunately require 150 sqm on the ground floor, because of the stepped floor and 66% according to the old building code. Hence, for example, the somewhat oversized "all-purpose room" and the satellite kitchen.

More illustrative than a house that unfortunately, due to reasons of avoiding a full floor, supposedly has to be too big without alternatives, one cannot illustrate the incompetence of an architect - not even with a redundant utility room ;-)

What by the way about the idea of a peephole?

Well, precisely that it is more of a liability acoustically than an enrichment.

Yes. When I look at the entire property (and remember my explanations from near the beginning of the topic), a shared underground garage almost insists itself.

with the other parties? You incorporated the underground garage into the architect's diss.

More illustrative than with a house that, unfortunately, due to full-storey-avoidance reasons, must supposedly be inevitably too large, one cannot illustrate an architect's incompetence – not even with a redundant utility room ;-)

Well, precisely that it is acoustically more of a liability than an enrichment.

Well, very constructive. As generally all your posts. °°
The peephole is only supposed to be in the hallway, not into the living room where the grand piano is.