/diy/ - Do It Yourself

Forcing people to walk around under a low ceiling is a bad idea (I had to do that on a boat).

A loft bed is better. You can raise the level of the bed to give enough height to stand up under it. Even if you can't, it's not so bad because you only need to walk a couple steps while under it. And it's not enclosed so it's less claustrophobic.

Here's a video of a guy who built a bathroom under a loft bed:
http://www.youtube.com/watch?v=NBYS3ZsC-cY&t=8m45s

Even if you just use the space underneath a loft bed as a wardrobe, you save precious square footage because you don't need a closet.

Murphy beds are also good. If you have three rooms, then you have three bedrooms if you have Murphy beds.