This chapter discusses the use and deployment of diagrams in the architectural and urban design practices of Estudio Teddy Cruz. Diagrams denote both a visualisation device providing an overview of often complex relations and a more abstract connotation pertaining to the relation of mostly heterogeneous forces and movements. The chapter will explore both dimensions as part and parcel of what will be termed ‘diagrammatic urbanism’. The studio engages in urban development projects at the intersection of social, economic, and material (urban/architectural) dynamics. In order to make these dynamic relations graspable the studios’ extensive use of diagrams becomes part and parcel of its socio-political scope. The studio’s diagrammatic urbanism expresses the use of aesthetic strategies coupled with direct social and political intervention, foregrounding a participatory form of urban activism. Highlighting concrete re-development projects but also focusing on the studio’s aim of re-conceptualising “trans-border urbanism beyond the property line” (Cruz, 2008), the chapter proposes a shift from the traditional notion of the model towards a progressive practice of emergent metamodelisation. Moving from products to processes, metamodelisation as practice and concept allows for further explorations of diagrams as ethico-aesthetic devices in support of emergent forms of translocal activism.