Other Housemates
When ownership legalities are squared away, it's time to confront the really tough issues—the ground rules for living together once you own, and the process of selling when one or both of you decides to move on. Discuss your expectations and hash out an agreement in writing before you have a mortgage hanging over the relationship.

Will anyone else live with you? Spell out whether friends, lovers, or family members can move in, and if so, what they'll be expected to contribute to the mortgage payment and maintenance expenses. If you're considering buying a vacation getaway, this conversation is extremely important. If you picture your beach cottage as a quiet refuge and your friend has a more-the-merrier party attitude, neither of you will be happy.