We are looking for tips on detailed bathroom planning

Hello,

we are currently in the process of detailing our bathroom planning. We have the following requirements:

Shower
- spacious shower with a shallow shower tray, dimensions 120x100 cm
- pre-wall installation for the shower to accommodate built-in fittings (we have estimated 15 cm depth)
- drywall partition to separate shower and bathtub
- glass shower wall on the above-mentioned drywall partition
- entrance to the shower with an outward-opening door

Bathtub
- drywall partition behind the bathtub to accommodate built-in fittings (we have estimated 15 cm depth)
- tub tiled and built in

Washbasin
- double washbasin so that with 2 adults and 2 children two faucets can be used at the same time (width 130-140 cm)
- actually only a mirror, but probably then a mirror cabinet only 10 cm deep. Built-in mirror cabinets look great, but then you would have to put another drywall partition in front and space would be lost.
Also, more costs are to be expected in that case. The argument for a mirror is that the children can also see themselves better because it hangs lower.
- 2 tall cabinets each with a laundry basket behind the lower door for dirty laundry.

Questions:
1. I assume that no underfloor heating will be installed under the shower and bathtub. And for the shower tray, even if it is not flush with the floor, a hole in the screed must be left to accommodate insulation and drain pipe?
2. Behind the pre-wall of the shower is the children's room; since the pipes are not in the load-bearing wall, I assume that, unlike old buildings, increased noise levels are not to be expected. Rather, noise originating from the shower tray, which in the best case will also be insulated. Correct?
3. We have estimated the pre-wall installations for WC, bathtub and shower with 15 cm depth. Correct?
4. We have estimated the drywall partition at the bathtub to be 85 cm high; is that about right to install the fittings?
5. For the double washbasin, probably only one wastewater drain pipe and only one fresh water pipe (each hot and cold) are necessary?
6. If we decide against a mirror cabinet, we do not yet know where to put the chargers for the electric toothbrushes. A socket would have to be installed in the tall cabinet. I found a wall mount for Braun toothbrushes on Google. It did not look bad at first glance. Does anyone have other ideas?
7. To the right of the tall cabinet we would like to install a small shelf where a laundry basket could also stand at the bottom (our utility/tech room is not very big).
8. A small bench or seating option under the window

We would be very happy to receive suggestions and opinions.

Have a nice evening.

Level shower tray)

You ask many questions across the entire spectrum (screed, masonry, plumbing, electrical, equipment...), so the number of extensive answers decreases...

Why are you planning in such deep detail?
Is it about new construction/renovation? What do you want to do yourself?

Most things will become clear when you sit down with a good plumber; they will then tell you everything you need to know.
For example, I don't understand why you assume a 15 cm wall thickness. Most stone formats would be, for example, 11.5 cm.

Hello , thanks for your reply. Yes, it did turn out quite extensive after all. I don't expect an answer to everything either. :-) If we get feedback on one or another question, that already helps us a lot. But I also think less would probably have been better, in hindsight. :) Most of the walls will be drywall, except maybe the wall between the shower and the bathtub, which could probably be built solidly. I assumed the dimensions of the drywall walls to generally be able to plan the space so that everything fits in a row. Best regards

What are you planning so deeply in detail for? Is it about new construction/renovation? What do you want to do yourself?

You haven't answered the questions to you now!

OMG that's almost our bathroom.

[ATTACH alt="IMG_20210222_175503.jpg" type="full"]57880[/ATTACH]
There are still a few display errors in the drawing, but roughly it fits; above the bath and the toilet is a double-wing window.

The sink is on a pre-wall installation and the toilet is centered.