Whenever I hear this question, my immediate response is no, you should not. Unless you met your BFF in a roommate circumstance (it happens!), you probably should nix the idea of shacking up with your BFF. It may sound like fun, and like something out of Girls or Friends, but in reality it causes a lot of stress and can hurt your friendship. I’ve certainly lost friends after choosing them as roommates, and if I could change things, I would choose to live with people to whom I am not as close.
Opposites attract. I like my friends for various reasons: they’re exciting, adventurous, nerdy, or obsessive, but these are not necessarily the qualities I would search for in a roommate. The friend who I love going out with until dawn isn’t necessarily someone I want to share close quarters with.
Even if your friends are similar to you, sometimes these similarities can be killer. Are you both compulsive cleaners? What happens when you leave dishes out for a few hours?
In my experience, it’s been the little things that have turned my friend-to-roommate relationships sour. Bad habits, like smoking, never taking out the trash, or forgetting to lock the door can usually be easy to confront with a roommate to whom you are not as close, but when you’re asking your friend to change her behavior, it suddenly becomes more personal.
When your friend can’t pay bills or rent (or you can’t), do you lend her money? Will she pay you back? What about if she ruins a wall and you don’t get part of your security deposit back? Renting an apartment has a lot to do with money and personal finances, areas that certainly get fuzzy in friendship. Resentment for lost money, late fees on bills, or extra generosity is almost always a relationship killer.
In my experience, I’ve found that it’s better to live with a friend of a friend, or even a stranger, in order to be a more democratic, compromising, and enjoyable roommate. The evil you know is different than the evil you don’t know– you know if your best friend is messy or snores or has a gross boyfriend– but those issues are always harder to resolve between friends than roommates. And don’t forget, your new roommate can still become a close friend!
You can be BFFs with your roommate, but rooming with your BFF can be a big mistake.

An ideal roomie situation