I have seen this on a few other forums and I thought it's quite a cool idea. If you meet some cool people here on the forum and want to chat to them then you can open your very own thread and give it a special name and then you can all chat together.
User A, User B and User C find out that they have so much in common and want to talk about all that together. So one of the Users opens a new thread and give it a special unique name. In the first entry you write down which members belong to this "apartment" and you can chat right away as long as you want.
Any languages are welcome aswell. So if User A, B and C all speak Spanish they are welcome to talk in their own thread in their own language. It's very open so feel free to add your own thing.