The old bathroom wasn't deserving of the word "bathroom" because there was not even the possibility to shower, the tap was not connected...The only things that worked was the toilet and fountain. So a metal frame was put against walls and ceiling and fitted with plasterboard. In the corners the wet area was fitted with special tape, and a new floor was poured after which tiling could be done.
Only the wet corner and the floor were tiled, the rest of the walls and ceiling were painted with paint specifically for bathrooms. See the beautiful end result here.