The principle theory behind the growing demand for real estate is that the earth is only so big, the population is increasing, and people will always need somewhere to live. Although this is true across the board, it is a far more tangible reality for families. While single people can often "bunk up" with a friend or crash with the cousins for a few months, families tend to have needs that preclude this kind of ad hoc housing; they often require a single-family rental to call home.