Hello again and many thanks once more for the lively discussion.
The suggestions have once again led to a new draft (see below; internal dimensions entered manually). On the ground floor, we have completely changed the staircase and enlarged the guest WC, so there is now the option for an additional shower. The space under the stairs could be used either for a small chest of drawers + pictures or additional wardrobe space (open staircase) or as extra storage space (closed staircase). Furthermore, we have planned a mirror in the wardrobe, which eliminates the need for the closet space opposite. In the kitchen, we have rotated the cooking island so that we can accommodate an additional counter with 2 bar stools. At this point, many thanks also for the idea of a continuous kitchen line with a hidden door. Friends of ours are currently implementing something like this, and we will definitely take a look at it.
On the upper floor, we have done without the storage room. As a result, we also have an open corridor with windows on both sides. Due to the changed staircase, we were able to enlarge the open space to 3.0m x 2.5m, which in our view is sufficient. As has been emphasized several times, it is simply a matter of taste. However, there remains the option of an open room with a reading corner or similar.
We do not see the draft as unproductive (admittedly, the second draft still had some significant shortcomings). In this third draft, we have now, thanks in part to your help, accommodated all the necessary rooms in sufficient size and appropriate arrangement, from our point of view. The “wasted” space is certainly not larger than in the often praised "Regnauer Munich" floor plan. Nevertheless, of course, we remain open to suggestions and criticism.
