How things have changed
When I was a sophomore at the University of Wisconsin-Madison, I shared an early-20th century brick house with four friends I'd met in the dorms the year before. It was hardly an unusual situation –– many of my peers lived in houses with more people.
It's probably not that unusual in Austin either, but it is illegal. Our current occupancy limits caps the number of "unrelated" people to four in a single-family home, three in a duplex unit or six in an apartment.