basement shower- maybe use plexiglass. walls are grey and the shower is this dark charcoal the color of the doors. then exposed pipe with lush large white curtains around the shower - inexpensive way to get a shower door!
Another bath inside whower idea: factory window shower - the BEST idea! Imagine this done huge-Japanese-bathroom style with an old claw-foot tub in an oversized shower, so you could have overflowy baths in a shower the size of a small room.