Bathroom renovation in house 1979

Hello everyone,
I am an enthusiastic reader of this forum and have already been able to get some tips.
We have bought a house from 1979 and are in the process of modernizing it. The bathrooms are also due for renovation. I have attached a plan. Since the bathroom on the upper floor is relatively small and we do not need the adjacent room, the idea is to combine both rooms. Still, as little effort as possible should be made regarding the water pipes. The wooden ceilings of the slant will be completely removed, and there should be a walk-in shower, a bathtub, two sinks, and a toilet. We would also like to put a washing machine in the bathroom!
We have already given it some thought and created a first sketch. But in this forum, there are always very knowledgeable users, so I just wanted to go on the forum to look for ideas and suggestions.
I look forward to your answers!!!
Best regards
Jan

Hello

Bathtub, shower, and toilet are usually only conditionally movable. The downpipes are where they are and cannot be relocated. If the distances, for example from the bathtub or especially from the toilet to the downpipe, become too large, it becomes difficult to maintain the slope for the wastewater pipes.
A flush-floor shower is also not always feasible.

Since the flush-floor shower is supposed to be moved into the other room, I rather suspect that it will not work.
With a normal shower tray or the bathtub, it (maybe) could work.

The wall that needs to be removed will presumably be removable. But always keep the statics in mind and consult a structural engineer at the slightest doubt. That doesn’t cost much and is worth it.

All in all, the shower will probably not be feasible where you would like to have it.
A professional has to measure and calculate a bit to see if there is still enough slope for the wastewater pipe on the route.

Would you have other wastewater pipes nearby at the new shower position? For example, kitchen?
My bathtub at its new location is also connected to the kitchen. I was lucky that this was feasible.

thank you very much for your reply! The idea is to install a second wall under the sloping roof, where the 5-inch drain pipe from the shower is to run. But this still really needs to be discussed with a professional! Another sewage pipe is in the wall that is to be partially demolished. The wall is only supposed to have a passage made in it! That's the plan ;)

The second wall, however, does not bring much, as far as I know, because the starting depth (shower drain) is possibly already too low.

The motto of the drain pipes is always a bit tricky. Because your pipes for the shower and bathtub absolutely have to run in the floor. Now often the question arises how the floor structure looks. With a wooden ceiling, you can be lucky or simply unlucky. Depending on whether the beams run in the right direction.

It is a massive floor!