There is the flipside too - completely libertarian approaches to cohabitation. Like my first roommates. We were all friends, had been since we were kids. They knew I kept things clean and tidy, and were of the opinion that there really wouldn't be any rules. By this point we'd probably lived together collectively for over a year if you tally up the trips taken together, weekends spent at other's houses, etc.
After we move in I clean the old house up, top to bottom, make some minor repairs to things like door knobs and such. Get it nice and cozy for the first visit of my GF.
I come home that night, not five hours later, and the living room is basically an ashtray (this was a long time ago youngin's - people still smoked back then). Some woman I didn't know was passed out on the couch with her shirt off (just a bra). The coffee table had what was, admittingly, a rather impressive tower constructed of beer cans, beer bottles, and other assorted items discarded over the course of a 20-something party session. One of my roommates GF (now wife) was literally asleep on the dining room table.
Oh and the spare sink we had in the laundry room, that I had spent a long time scrubbing earlier, was clogged with vomit. As was the toilet.
)
