200 m² maisonette in an existing building, interior (almost) fully customizable

And here is an example of how to bring daylight into the hallway Copyright protected - Mine!

The staircase opening itself already brings quite a bit of light down. I'll show a picture tomorrow of how that works.

Me again :)

First of all, a heartfelt thank you for you and your commitment. You are absolutely right regarding "being in love" with the floor plan. But luckily I registered here and received very good inputs and experiences from some users and especially from you. Don’t worry, they don’t just bounce off me. I am open to changes and improvements; I myself still lack experience in many things.

Your last floor plan really appeals to my wife and me. Yes, the stylish free-standing staircase is gone, but that way there would be much more usable space, especially on the upper floor. The walking paths would also be significantly better. To the south, my wife and I would still have our "own realm," perhaps I would shift the wall in the middle up a little bit so that one can go from the master bedroom to the toilet at night without having to go through the hallway (basically an entrance to the parents’ area). The children’s rooms get more light, the fitness area gains significantly in size, and storage space would also be available in that room if needed (you could also put the washing machine and dryer there). I have to say, all in all really great improvements, I will discuss this with the architect next week! :)

But a load-bearing existing wall? I was just wondering because the planned staircase at your place also pierces it, and the sliding door in a solid wall is also suspicious to me ;) Would the passage then have to be supported or does it already exist?

The passage in the basement between the hall and the kitchen area already exists. According to the architect, the staircase planned so far could pierce the ceiling or the wall at this spot without structural problems. Whether the staircase can be placed at the spot you showed is also a question for the architect. And then you would have to see which of the placements you suggested is better for the upper floor, downstairs it doesn’t make much difference now.

In the shaded recess!

Do you mean the bay window at the very bottom left of the plan with “shaded recess”? For clarity, on the upper floor this is windowless, in the basement it is pretty much the brightest spot in the whole apartment because light can enter from almost all sides. I’m attaching a photo to illustrate (please ignore the current mess).

Thanks again for the great inputs!

The stairwell itself already brings quite a bit of light down. I'll show a picture tomorrow of how that works.

Great, I'm looking forward to it!

maybe I would move the wall in the middle up a little bit, then you can go to the toilet from the master bedroom at night without having to go through the hallway (basically an entrance to the parents' area).

That was consciously planned exactly as it is now! The bathroom was meant to belong to all family members... I think it won't be a hardship to walk 2 meters for world peace on the toilet :)

And here is an example of how to bring daylight into the hallway

Yes, even into the hallway under the glass blocks ;-)