Sororities at IU, at least when I was there, required members to live in for a certain amount of time. Usually it was 2 years, some houses required 3. (I am going to assume they made exceptions for sisters studying abroad, doing internships, student teaching or anything else that required them to be away from campus for a semester or a year.) The houses there are ginormous though. I am not sure if that's changed...maybe someone who is currently at IU can tell me.