ᐅ Upper Floor Layout with Sloped Ceilings – What Can Be Improved?

Hello everyone.
My partner and I designed our floor plan ourselves and have now received the attached drawing.
The main dimensions were intended to be 11 x 9 meters (36 x 30 feet), but the current drawing shows 11 x 9.5 meters (36 x 31 feet). We have already requested a revision.

However, we are not completely satisfied with the layout of the upper floor:

- The bathroom is too large
- The upper left room is not optimally shaped

By reducing the size of the house, we will probably be able to make the bathroom and the lower left room smaller. However, it will then be difficult to access the bathroom, since the master bedroom cannot really be made any smaller. The partition wall would then be at the level of the staircase. The staircase is also shown as 4 meters (13 feet) long. Is there potential to reduce this length with a standard ceiling height? The steps, of course, should meet building regulations.

For your information: South is roughly behind the building. My partner does not want the master bedroom and the child's bedroom to be next to each other. Also, the bathroom cannot be placed in the upper left corner due to the layout of the ground floor.

Do you have any ideas on what else could be changed or improved?