Young people appropriate and redefine built environments through their everyday playful practices. Among a widening spectrum of young city dwellers, skateboarders transform urban spaces by exploring terrains and performing unforeseen uses. These urban explorations ascribe new meanings and pleasures to otherwise mundane built forms. Waxing ledges is a ubiquitous practice among skateboarders that signals creative appropriation through the application of wax on rough surfaces. The smoothening of ledges enables speed and exhilaration, while the traces engraved on the urban landscape communicate to other skateboarders a pleasurable space. This article chronicles the emergence of an alternative ethic of care for built environments through the urban practice of skateboarding. It focuses on the Chicago skateboarding scene and draws from data gathered through ethnographic fieldwork during 2009–2010. Skateboarders' ethic of care for built environments is further developed in this article through the coupling of skateboarding with a host of sustainability-themed projects such as recycled installation art at the Museum of Contemporary Art Chicago and grassroots activism from the Little Village Environmental Justice Organization. These examples highlight the intersections of skateboarding and the sustainability agenda in the city of Chicago. Furthermore, this article pushes the limits of this agenda by exposing linkages with processes of youth cooptation and criminalisation as the Chicago skateboarding scene takes shape throughout both sanctioned skate parks and illicit skate spots. Skateboarders forward an alternative sustainability through bottom-up playful tactics that promote an ethic of care for built environments. This article argues for young people as agents of change through the everyday practice of skateboarding.