To determine effective relationships between the built environment and health and well-being, a transdisciplinary team of architectural, behavioral and health scientists developed a built environment coding system (UMBECS). They examined the relationship of resulting streetscape features to health and well-being at the block level. The research team conducted studies of the validity of UMBECS focusing on children through school conduct and grades, and on elders through a longitudinal cognitive functioning study. For children, contrary to popularly held views, commercial-residential mix was as effective as a high proportion of residential use in predicting children's school outcomes (i.e., better conduct, achievement, effort, and grades). For elders, modest but statistically significant relationships existed between block-level features, elders' neighboring behaviors, and social support, which in turn were significantly associated with cognitive and affective functioning. These findings suggest the utility of this built environment coding system for examining the relationship of built environment features to residents' health and well-being. UMBECS offers a useful tool for developing a viable transdisciplinary model of the role of the built environment in behavioral and health outcomes.