By the way, the stairs, and doors, are appropriate for weird physiologies as well, so no "a centaur can't go through here" comments.
There are around 20 individual beds per room, to a total of 40 for each grade and 160 students in general. They are arranged with 11 in the wall opposite to the door and nine on the door wall. Each student has around 9 m² of floor area for him/herself (that is a square of slightly less than 10 feet on each side with the bed on the middle, close to the wall), with a 1.5 meter (5 feet) lane separating the room. It's not cramped at all, unless you are a literal giant so, even a horse could sleep there very well.
The common areas are furnished, and have mini libraries, a television (with a latest gen W-box console), a couple of public computers each and even a small snack bar with a fridge. Your characters aren't living in spartan conditions at all so there's no reason for than to complain.
The place is as good as it can be without veering into rich children pampering syndrome.
PS: Just to be clear about this. Both the common areas and all entrance and exits have CCTV cameras, to keep everyone safe while maintaining the rooms privacy.