In my house sharing days I actually applied to rent a room that was twin bed sized. It had storage shelves near the ceiling, which was fine because you had to stand on the bed to move around anyway. Somebody else got it and I ended up renting a corner of a finished attic (with skylights!!) along with 4 other people. I put up tapestries to section it off one night while my one of my attic mates was banging some dude she brought home from a party.