Nicola Bludau wrote:If this is not done 100% you can wreck a lot. There is no advantage of a wet room. Just get a "normal" shower basin (80x 8o cm) you will need that space anyway.
Even if done conventionally, you need to seal the walls and everything VERY well. A wet room looks modern, but any leak causes problems, and a house with mould is about the last thing I would like.
If you choose your dream, get a very good professional. Also, the bathroom needs a good ventilation - the window has to be used after every shower and be big enough.
Jay Angler wrote:About what is the number of square feet you're working with?
1930's house may not originally had indoor plumbing.
You mention "level" but in fact if your goal is a wet room I would treat the whole room as if it was a shower stall making sure that it was high at the edges and every bit sloped to the floor drain.