Bathroom renovation 12 sqm - Ideas for the T-solution - sufficient space?

Dear community,

we are currently planning the renovation of a single-family house from 1974. In this context, a new bathroom will be built on the upper floor, which will have 12 sqm in the future by removing a partition wall (2.73m x 448.5m).

I would very much like to install a T-solution. Unfortunately, I have no idea what minimum or comfortable dimensions should be observed to ensure that the passages, splash protection, distances, movement areas, etc. are comfortable.

In terms of equipment, we would like to have an open shower, a toilet, a double washbasin, and a freestanding bathtub (min. 1.70m x 0.80m).

Do you think that would work like this?
How long should the shower wall be at least to prevent water from splashing out completely? How wide should the "privacy wall" of the toilet be so that one can sit in it comfortably? How wide should the passage (distance between the bathtub and the shower wall) be at least so that one can pass through comfortably?

Do you possibly have another suggestion regarding the arrangement? I am open to everything :)

Thank you for your advice.
Attached is also the floor plan with my first draft

How large are the windows and the parapet heights? How large is the door distance to the corner?

That can all work like that.

How large are the windows and the parapet heights? How big is the door distance to the corner? That can all work like this.

large window: 131.5 x 77. PH: 134 --> so a narrow, long window with enough space to put something underneath small window: 57 x 72. PH: 137 door distance to the corner: 16.5 width of the door: 84 best regards

Bathtub directly under the window?

Where should the drains go? What is underneath there?

Bathtub directly under the window?

Where should the drains go? What is underneath there?

Yes, I wanted to place the bathtub directly under the window - is there any objection to that?
The drainage must be completely reinstalled, screed etc. will be renewed.

The drainage must be completely relaid,

What is beneath this room? The drainage has to go somewhere as well.

It is not very productive to create a separate thread for every change, where there are only room sections each time. After all, a house is something where everything works together.