I chose sauna because it's small room and it's pretty easy to create (beginner-level modeling), besides - I don't need to think of environment story telling who lives here or what happens here. I've been doing this design for the last three days. I still need to make stones for the stove, ladles, buckets, and a few other things specific to the bathhouse.

Next time I want to combine you wishes into one design for next room, Maybe it'll be dorm/hotel/??? with "voyeuristic" elements.

Draft test render #1 (is to cold color balance if compared with reference)