Roommate advise please?

Ok, so I am a year older than my best friend, and we are thinking about dorming together in college next year after she graduates. So ill be sophomore in college and she will be a freshmen. We have been best friends for a while and are EXTREMELY understanding of each other. We don't fight because of this. (I guess we are like sisters in closeness) Anyway, I am a little hesitant about dorming with her becase she is such a good friend, and i have heard best friends dorming desroys friendships. Neither of us have a dominant personallity or are controlling, but still i am afraid too much time together in a dorm room might be too much. Once she is allowed to live off campus we are going to get a group and get a small house and that will be awesome, but do you think dorming wih your best friend is ALWAYS a bad idea or is there exceptions?