Waterproofing wet rooms involves priming the floor, the lower section of the walls and the whole of the wall area around the shower and then covering with a syrupy membrane. Once it’s set, the room is then tiled.
Choose wall-hung fittings wherever possible. It will make your bathroom much easier to clean and give the illusion of space, too. Try to keep walls clear of clutter and consider fitting underfloor heating, so you can keep it toasty without taking up space with wall-hung
It’s also a good idea to visit a local bathroom showroom for advice, as its designers will have plenty of experience in maximising space while at the same time minimising costly mistakes.