Rapid urbanization and new construction estimated to be 250 times NYC by 2050, is increasing traffic congestion, pollution and related health threats. Understanding consequences of urban design choices on mobility, sustainability and health is hence a necessity and requires development of a new design toolkit that allows non-specialized urban designers to quantify performance of mobility solutions, sustainability, public health impacts, pedestrian thermal comfort and pollution exposure during the earliest stages of a design process. Embedded in a generative, performance driven design process, such a tool can significantly facilitate the design of healthy and sustainable urban habitats that promote active mobility.