On our campus, we don't have houses, but each sorority/fraternity has their own dorm building.

like these. They house 40 plus an RD (which may or may not be a member of the sorority/fraternity) The sorority houses have members only, while sometimes the fraternities have random independents when they cannot fill the house (usually after recruitment, pledges move in and independents move out--although this year, there was a boy that did not get into the fraternity whose dorm he was living in, and his fraternity dorm was full, so he stayed there--sticky situation)
The rules for live-ins vary from sorority to sorority, but for us, all members of EC (President, Vice President, Secretary, Treasurer, Phi Director, Membership Director, Panhel Delegate, Panhel Recruitment team member, and someone filling another posistion on Panhel) must live in the house. Also if the house does not fill with people being able to live wherever they want (which doesn't happen) they may be assigned to live in the house. (So we don't have independents)
The dorms include 2 lobbys--a formal and an informal, and a kitchen. It is campus housing, and since we HAVE to live on campus all four years, it is as good as we can get.
This is the formal lobby and informal and another formal, informal