When the accommodations are small, think big, like this Tiny Room Pallet Bunk Bed! The design magazines say "build up," and this is what we did here. This project used five pallets and took about 10 hours to build. But, it was free, so that leaves more money for fun family stuff. :)
Our Tiny Room Pallet Bunk Bed:
We have a tiny room where my youngest sons sleep. The problem is that he's rapidly outgrowing the room, so I needed to do something. The space to build the bunk bed was 6' x 4'. By sheer luck, I happened to come by 6' x 4' pallet out of an office refurb. I broke several pallets apart to get the free deck boards I needed. And then, I simply built as time permitted. My other goal was to give him a little play area underneath and to have a place to store the existing drawers he uses. I used some of the stringer boards to create support and a ladder frame. The sturdy ladder lets him get in and out of bed quickly and safely.