Poor floor plan with sloping roof attic

Well, you do need some range of motion on the toilet, even if you should gain 10 kilos. But even slim people need to be able to move their arm. To me, the height dimensions look more like a closet. There are no windows either, right? Maybe consider mounting sliding doors in front of the slope instead of a sliding door wardrobe and using it as a closet and setting up something like a bathroom in the closet area (whatever kind of room that is)

We were able to take over the sliding wardrobe from my mother. It was very expensive and we thought about using it as a room divider. This wardrobe HxWxD: 210x290x65 we cannot fit into the roof slope. Behind it, everything would be unused?! In the knee wall area, a wardrobe is planned for the width, so that the doors in front are about 110cm... The sliding door wardrobe is very large, with pull-out shelves, ideal for the bedroom next door...

This cabinet HxWxD: 210x290x65 we can't get into the sloping roof space.

No, of course you can’t get a tall cabinet under a side roof slope. My suggestion is based on the idea that you build a custom fitted cabinet under a sloping roof yourself or have it made by a carpenter, in front of which you then place sliding door elements. As I already said: it looks like a side area to me, and therefore with the small fridge absolutely not suitable at all for a room like a bathroom, so you should take a look at how the rest of the floor looks.

A complete floor plan of the floor would be clever.

Take a photo of the side area. Edit: sorry, but my photos are only now loading.. I’m only now seeing that one post #6 as well.

Attached is a plan of the side view...

Attached is still the total area of the attic. The wall marked in red was not built at that time.

The currently small roof window would be removed and replaced with one of the same size as on the other side.

So the bathroom floor plan is basically at the top of the plan?

Now the contour lines in the overall floor plan would still be very useful. And the exact position with dimensions of the roof window.

Basically, I would try to build a wall at the 180 cm height line, on the left side of the staircase then the shower, next to it on the "new" wall the toilet, then the drainage pipe to the roof penetration could probably also be routed somehow in the separated side area. And then the sink. But for that, one would need the above-mentioned values.

I have tried to sketch something from your distorted pictures. Placing a cupboard in front of the window is difficult. I have drawn the 2 m line. Your 1.8 m cannot be correct according to the section.

You have now arbitrarily positioned the roof window in the bathroom area - right? According to the statements, it should be somewhat further down the plan because the small window was replaced by a large one. At least that's how I understood it, hence the request for the exact position and also the height of the bottom edge.