Legal and technical requirements in bathroom planning?

Hello,
attached is the sketch of the renovation 75 with self-drawn dimensions. Fireplace, door, window, everything else is outside, what should go inside: a shower, a bidet, a washbasin, a heater and of course some kind of cabinet, a tall narrow one from Ikea is enough.
The pipes will be completely redone anyway, the only thing is the adjustment factor at dad’s place, you know how it is with the old building and all... the washbasin has always been on the left side until now, it should stay there because it is unimaginable that it could now be on the other side :(

No toilet? Where is the drain pipe of the toilet if available? Draw how you would like it.

That is in a separate room

Maybe it works like this? The partition either made of glass or double-walled clear or frosted panel about 2 cm thick and 1.80 m high.

Hello Hanghaus,
this is more or less how I imagined it, only the heating pipes that run roughly where the sink is drawn are still worrying me, I still have to come up with something.