Installation of the bathtub back wall without tiles

Hello everyone,

we are currently in the planning phase of our single-family house and are currently dealing with the bathroom design. For the bathtub, we have decided on a built-in bathtub. At first we wanted a freestanding tub, but that was too expensive for us, and it would have created a very narrow space behind the tub that would be difficult to clean. We like the built-in bathtub because it doesn't have this disadvantage, but still visually comes close to a freestanding tub.
What we don't like at all, however, are tiles behind the tub. Therefore, we are looking for alternatives here that are not too costly and, if possible, can also be applied as DIY. You can see this in many pictures of modern bathrooms, but of course, you don't learn anything about durability and robustness there.

The back wall of the tub should be built about 35 cm higher than the edge of the tub. The fittings are to be installed on this back wall. That’s the plan so far...
After research and various discussions, a combination of lime-cement plaster on this wall and a coat of elephant skin or latex paint in the splash water area seems suitable to me, as it is cost-effective and nice. Possibly I would only paint the area directly above the tub so that the rest remains breathable.
Has anyone had experience with this combination? Is it sufficiently water-repellent then? Or would you rather advise against it completely or recommend another plaster/paint combination? What alternatives would there be?
I would be very grateful for any advice.

Best regards

Glass, printed with a design that you like? And somehow color-match the cutout for the fittings? We are currently thinking about this for our showers as well as for our bathtub.

You can do it if you don't splash or shower much. You just have to make sure the joint is done very cleanly and stays intact. Then not much can happen to it. You can also paint with mineral paint, e.g. from Keim. It is water-resistant.

Thank you for the feedback.

Glass is also rather not our taste. We have specifically planned a sufficiently large shower niche to avoid a glass door there.

We actually do not shower in the bathtub. We have not splashed around so far either, but that may look different with children.

Just for your information, as it may be relevant regarding moisture: We are getting a ventilation system.

Just for your information, as it might be relevant regarding moisture: we are getting a ventilation system.

It won't help you if you splash 5 liters of water against your wall ;)

As a back wall, you can use the following materials:
- Tiles
- Glass or similar full-surface panel
- Elephant skin/latex paint (I find it absolutely ugly for a stylish bathroom...)
- Waterproof plasters/surface finishes like Beton Ciré and the like
- Lime plaster with olive oil soap or matte wax from Steinöl
- Tadelakt

- Lime plaster treated with olive oil soap or matte wax of the stone oil

Can a "standard" felted lime plaster be treated with this, or does the plaster have to be processed differently from the ground up? For example, I have only heard of olive oil soap in connection with Tadelakt so far. Are there particularly recommended providers for something like this?