Our proposal will extend the reach of research findings from Youth.hood—a community-engaged research project exploring how built environments shape social connectedness and health for youth living in under-resourced areas. Youth.hood grew out of the success of our long-standing collaboration (SFU Health Sciences/Urban Studies, South Vancouver Neighbourhood House) to uncover social infrastructure gaps in South Vancouver: inequities that effectively disadvantage the health and resilience of residents. Youth.hood findings tell a compelling story of the role that social infrastructure plays in connectedness, cultural identity, and resilience, and how a lack of active transportation infrastructure, neighbourhood upkeep, and quality youth-friendly spaces create barriers to wellbeing. Our proposal will mobilize findings with an aim to advance healthier built environments for youth in South Vancouver, and inform broader dialogue and practice on planning of healthier cities with and for young people. Through tools and engagement activities co-designed and co-delivered with community, our proposal promises to achieve impacts at multiple levels—including environmental, policy, and practice—in Vancouver, and for city building more broadly.