This is an idea I took from an FCE coursebook when I lost the original. It involves two groups of students - one group owns a house with spare rooms and the other group is looking for a place to live.
The first group must come up with rules (You must not smoke; Parties are allowed; You needn't cook for everyone) etc. while the other group thinks of questions to ask when they meet (Can we smoke? Are we allowed pets? etc.)
Then they meet and chaos ensues while they argue over rules, and ultimately, decide whether they would live together.