A large number of today's retired home buyers are seeking a community that caters to their active lifestyle. Maryland couple Jack and Ellen Hart, for example, wanted to play year-round golf. After considering developments in Arizona, California, and Florida, the Harts decided on "The Plantation," an adult community in Leesburg, Va. Adult communities are age-restricted housing developments for active adults. Adult communities are defined by the age of their residents--at least 80 percent of a community's units must be occupied by at least one person who is over 55 years old. Swimming, golf, tennis, crafts, and transportation to local stores usually typify the offerings of such communities.