[@Arya10108909] 
The dorms in Derandfella work like this:
[list]
[*] Each dorm has a small separate room with a lavatory for each student.
[*] All students in a dorm have a shared kitchen, living room, bathroom/shower room etc.
[*] If students want to, they may move their furniture to another room to share a room with another student
[/list]
So you can have roommates as long as the person you want to room with agrees.