[33girl]

Are these houses on campus or off campus?

If they're on, the school can't say 5 can have houses and 5 cannot and be making no moves to change it. That makes no sense and is discriminatory and your national headquarters should be contacted ASAP.

If they're off campus, the school has nothing to do with it. They may tell you they do - they may cite local laws which don't exist - they may spin the rumor mill - but the school has NOTHING to do with it. Ask the other groups who their landlord is and if he/she has any other similar houses available.