In the US they're called roommates so that's what I'm using.
Roommates old and current. I have been so unbelievably lucky to have lived with four specific people who have not just been the people I live with, they've been fully fledged friends.
I still refer to Jacob and Lola as my roommates and obviously Dan and David who are my roommates now.
It's a rare and special thing to make new friends in any case once you're outside the world of school or uni or if you don't have the kind of steady job where you can have work friends. It's also a rare and special thing to move in with close friends and remain close friends, and also to move in with someone you are only acquainted with and end up counting them as one of your best friends and kindred spirits.
I can never express enough my appreciation for these people and how they enrich my life and make the place I live a home. Happy thought of the day!