Maybe a common room where people can initially talk about what they intend to work on. (Eliezer says: This needs either strong group norms or built-in limits on talk time to avoid becoming a social chat timesink.)

I discussed this a bit with tsakinis, and I think that we can indeed create group norms that do the following:

• Suggest people that are having a (long) discussion to do so in a private room
• Welcome new people, find out what they're working on, and then go off together to do a pomodoro in one of the study rooms

This will mean that someone who joins "just to have a look" will be positively welcomed, and get his first taste of the social work encouragement. The alternative, no lobby room, means that a new person will have to choose between arbitrary study rooms, then "drop in" on people that are working. For someone who's unsure about the entire thing, this doesn't help at all.