The bathtub is placed on the floor. Everything else is not well thought out for me. Advantage: low entry, simple, unassuming, plain. I see that quite often in [Neubau]!
Who sees that differently? I've never heard of placing a tub directly on the screed. It doesn't help either to put underfloor heating under the tub in the styrofoam block. You use supports and then you can run the underfloor heating underneath the tub, but it would still stand on the raw ceiling.