Window sill height 130 in the bedroom / study?

Having a skylight in the bathroom is certainly a nice thing.

Definitely. With 8.6m of wall length, facing south and west, without a single sanitary fixture on any of those meters, one might almost get the idea that it could also work without one upstairs :)

No idea why there is now a debate about me having to swap the rooms.

No idea why there is now a debate here that I should swap the rooms.

So that you can solve your window problem :)

For the bathroom? Or for what? Why counteract when you can simply change the rooms? The design of the upper floor is no rocket science. These are four almost identical rooms. The main bathroom can be very well positioned above the utility room with a short (heating) route, etc.

Actually a great idea. The fact that room arrangement, lighting, views, and thus ultimately the perspectives are connected, unfortunately seems impossible to convey. Priority 1 seems to be that there are no views - and this is absolutely perfectly achieved here.

No idea why there is now a debate about me having to swap the rooms.

That means you actually only wanted our advice on how to layout the windows like hanging pictures – so only being directed which nail to drive further left/right/top/bottom; planning imperfections are already "untouchable" like "don't confuse me with facts"? – then you are "in the wrong place" here: you have ended up in a forum whose community is used to trying to save every child not yet "finally fallen into the well." That doesn’t have to be a mistake, but unfortunately not every questioner can accept that :-(

How do you think the upper floor could be divided more sensibly and what would it change about the window arrangement?