7m² bathroom planning - feedback would be appreciated!

Hello everyone,

as introduced in another thread just now, we completed our downstairs bathroom last fall. This summer/fall, the upstairs bathroom is next.

We have finalized our planning and are already polishing the details. Since we received very good input here for the downstairs bathroom planning, I would also like to share my plans for the upstairs bathroom in the hope of receiving tips here as well.

Basically about the project (from left in order) and associated questions:

General

[*]The floor should be laid with black tiles (Okinawa-R-Carbon)
[*]Wall tiles will only be installed in the shower
[*]The ceiling will be suspended and fitted with spotlights

Left

[*]On the left when entering, we plan a shower. There should be a glass wall here (100cm x 200cm) -> Should this actually be extended all the way to the floor, or is it enough to tile the back wall of the shelf and use it as the back wall?
[*]We want to buy the shelf externally (2x base cabinets 40x40x80cm) and have it "boxed in" by the drywall builder
[*]The shower should be walk-in at floor level. Unlike downstairs, we plan not to tile the floor but to use a black (3cm high) shower tray in slate look. Is it possible with such trays to design the entrance flush without much effort?
[*]In the drywall partition (shower-toilet) we want to install a shelf from the shower side. Either at the top of the wall, as drawn, or alternatively a display cabinet standing on the floor.
[*]On the back of the display cabinet, where there is still space, an EMCO module for toilet brush, toilet paper, and waste bin should be installed.
[*]The toilet is a Subway 2.0
[*]On the right side

Right

[*]At the entrance on the right is a conventional black towel holder
[*]Then follow various fittings. We are unsure how to position the washbasin (W) and tall cabinet (H). From the entrance door in order, we have 3 different scenarios:

[*]W/H/H --> Passage is narrowest here
[*]H/W/H --> Passage is good and the arrangement is symmetrical – unfortunately the distance of about 10cm between the individual modules seems very small to me
[*]H/H/W --> Passage is optimal. On the left at the W, the wall can be disturbing when washing oneself.

Looking forward to your feedback.
We are a family with 3 children and therefore, in my opinion, urgently need a double washbasin so the kids don’t get in each other’s way while brushing their teeth in the evening.

What is that block next to the door measuring 35 x 100mm? Is that some kind of load-bearing wall? If not, can it be removed?

Originally, we planned to install only a glass pane there. In the meantime, our idea is to install a bench in front of it using drywall and to place 2 small cabinets inside it - see [Bild 6 Abbildung oben rechts].

Where is the bathtub drain? Towards the toilet? If not, can it be extended to the other wall? Underfloor heating available?

If the shower must be towards the toilet because of the drain, then I would make the WC/shower partition as an L-shape solution. In the upper area with a glass insert (flush inside) or alternatively tiled up to the top and in the shower room then with low-voltage LED in a suspended ceiling.

I don’t see that working like that.

For a shower like the one you’re planning, you need about 1.40m of glass on the side to keep the spray water outside. That won’t work.

I would place the toilet in front of the head of the shower.

I don’t see a window. Just to be sure: You want BLACK tiles in a small, interior bathroom?

( edit: Forget the question about the window. Looking at pictures helps… )