I don't know if this was really thought through seriously here. We also have a small gallery on the upper floor. But it is never a quiet retreat where you could read a book. Especially not with 2 children's rooms next door. Besides, the place is simply not cozy enough. It’s a hallway – also in your case.
In addition, there is this tiny mentality that enlarging the children's rooms from 10 to 13 m² would be pure luxury. Don't get me wrong, it is of course an improvement and 13 m² children's rooms are no child torture. I just wonder if you really want to waste the space on a (then certainly very nice) hallway that is 99% unused. In my opinion, it would be better to give the children plenty of space right away.
The hallway is nice – no question, but bigger children's rooms are nicer.
Even if it is only minimally better, the children's rooms are more like 14 sqm rather than 13 sqm. And even if the hallway upstairs will not be a place full of peace, it will be nice. The children will also cuddle there and be able to look at their books. In the evening, I want to read the good night story there. We have a very large, full bookshelf. Otherwise, I didn't know any place where we could accommodate a small library. That was our basic idea for this gallery.
The floor plan as such is tailored to our daily routines. We will definitely take into account the notes regarding the shower, the doors by the utility room and kitchen, swapping the dressing room and bedroom, etc., during further planning and are very grateful for your effort!