Is it possible to make a storage compartment in the entire shower side wall?

We have an almost 50cm wide compartment in a 110cm wide wall (part of a ceiling-high T-wall). 10cm deep in 17er KS. Was not an issue, over the entire width probably more difficult.

This shower is completely built.

Is it, or are we still in the planning phase?

It is already bricked. Of course, one could have planned that beforehand, then we would have made the walls even thicker, but we didn’t. That’s why it has to work somehow like this. How deep should a storage compartment be at least? 7cm? Then 10 cm would still remain. That would almost be an 11.5 cm wall^^. Is that possible?

Just to understand, the wall being talked about doesn't actually go all the way to the ceiling according to the initial post, right? Consequently, it shouldn't serve any function other than separating the shower. Therefore, you should be able to take something out there fairly easily.

But I think the best/easiest thing would be if you posted a picture or at least a sketch of the situation.

Attached is the situation. Yellow is meant to represent the storage compartment. Correct, the shower has no function except for the shower enclosure.

Then that should actually be relatively easy. Although the ease refers to static concerns, the implementation is probably not that simple either. Because either you take out a complete strip and install a lintel beforehand (but the 1.50m won't quite work, more like 1m or so). Or you would have to chisel/mill the cavity into the wall, which is not easy either, and above all, I think you better need 10cm or more of shelf space. That means almost the entire wall, and that would weaken it too much. In variant 1, the question remains how you then seal the niche, although you could insert a piece of glass there.