Public-health models indicate that many factors affect human health: biology, individual behavior, social and economic factors, policies and services, and environments. A key aspect of the Design for  Health (DFH) project has been clearly identifying how the built environment, including the planted environment, affects health. Often, planners and designers rely on commonsense notions of healthy environments when the healthiness may have far more to do with the kind of people there than the kind of place. Giving the environment its due without overestimating its influence is a major focus of DFH. Key questions include: