Urban commons is presented as a challenge of collaborative governance. This study delivers a normative perspective to analyse and evaluate processes and outcomes of the governance of urban commons. It demonstrates the development and application of the perspective in action research on Amsterdam’s Zero Waste Lab case, as a way to better understand successful and failing institutions in a concrete practice and to design interventions for improvement. Consequently, the (im)plausibility of collective action in urban communities and the participation of public actors present dilemmas for urban commons. The study specifically synthesises urban commons and collaborative governance scholarship and relates also in general to the transition towards co-creation in governing the city, e.g. in public administration or planning.