It all depends on what uni you're at. I was at UCL and we had a false fire alarm once in the whole year in my student house (halls at UCL = catered accommodation, everything else is "student houses") . My other half (at the time) was at another university, and at one stage the fire alarms were going off there every night. as to sharing with 18 year olds, not a problem. I guarantee you that they'll be one or two who are messy as hell (normally attempting to turn the kitchen into a public health risk), but you get people like that who are older as well, so I cannot complain.