walk-in shower size

Definitely a good idea to move the door:


So then like this ... all installations can be on the lower wall:


On the left there can still be storage at washbasin height, so no tall cabinets, unless you need the space.

This might cost a bit more now because the door has to be moved, but this way the shower can be easily realized with a wall and without a door.

Oops, moving the door would cost 3000 euros. But I found someone who can do it. The only thing that still worries me is whether it can simply be done or if there would be a structural problem at the location of the new door. Then it will probably be difficult with a run-of-the-mill handyman.

Is the wall only 11 cm thick there? Basically, I wouldn't see any problem with that. If the contractor offers it to you for 3000 euros (with what justification, actually?), then it should technically be possible.

What about the water connections? Especially the level-floor drain for the shower? Is that that simple or is it perhaps included in the 3000 euros.

3000 euros is indeed a lot, but if in doubt, I would bite the bullet and choose everything from one source. Then no one can come afterwards and possibly try to shift blame onto others.

Yes, according to the plan it is a less thick wall (I think, 11 or 13 cm). The contractor charges money for the total package: creating new plans, removal of old material, bricking up the door opening, making a new one, installing the door, replastering, and labor hours. Oh yes, a quick-build wall at the end of the shower is also included. Still, I find it quite steep.

Clarify whether the installation or connection of the floor-level shower is included. If that is the complete package, I would pay the 3000 euros. Because doing everything as separate actions also costs money and especially time. You also have to dispose of the waste = demolition.

Yes, the installation of the connection for the shower is included. A shower tray is required for the shower; unfortunately, a continuous floor will not be done. I can still plan the connections myself. I think I will order the shower and the connection for the washbasin at the locations you suggested. It will be kind of awkward when entering the bathroom at first, but once the door is moved, it will be fine. The craftsman said that moving a door for interior doors costs about 1000 euros.