We started with a bunk house and they work great with kids that age... Then we realized that we were loosing living space, and the kids really only slept in there.
We then purchased a RE ( Rear Entertainment ) back in "08" when our kids were 14 and 9.. They had to fold down the couch to sleep, and we did not loose any valuable living space.. It worked GREAT ! !
We now have a RL ( Rear Living ) and the kids are 24 and 19.. they either fold down the couch, or sleep on a portable 3" thick X 36" mattress and are perfectly fine with it !