As she approached retirement, Clare Lynch began to think about downsizing from her Silver Spring, Md., split-level, where she had lived for 22 years. After considering several towns near the Chesapeake Bay, she moved her search to Leisure World, a community of 5,600 homes for those ages 55 and over, spread across 610 acres in northern Silver Spring, Md. She toured dozens of homes there before settling on a one-level, two-bedroom, two-bathroom house attached to two others.