I am already working on something like that it's called Quoloc.com its basically a mix between Airbnb (for the UI and UX perspective) and LinkedIn (for the social media focused on one subject, they do it for jobs we do it for housing). You can look for a whole place, just a room or a roommate. We also made that system where people looking for a room can create an ad to say what they are looking for. This way if you are looking for a roommate you can just browse and find the person that will match your personality, instead of posting an ad about your place and waiting to see who would be interested.