Purpose The temporary use of vacant spaces as a format to co-produce public services is becoming popular. Research addressing the question of whether the public outcomes created in temporary co-production lead to sustainable results is lacking. The purpose of this paper is to explore the potential sustainability of public outcomes created through temporary co-production. Design/methodology/approach The paper builds on the literature on creating sustainable outcomes in policy making and on co-production to design a theoretical framework that captures the sustainable co-production of public outcomes. Attention is directed to problem solving and capacity building, and to addressing the needs of society today and being responsive to the needs of tomorrow. A study of 8 temporary initiatives set in a large city in Flanders and 35 in-depth interviews with public servants, project coordinators and citizen co-producers provide empirical data for this exploratory study of the creation of sustainable outcomes in temporary co-production. Findings The data indicate that lasting collaborations, institutionalized (flexible) processes and empowered citizens support the creation of sustainable results from temporary co-production. Originality/value The paper bridges the literature on policy capacity, the co-production of public services and value creation. By doing so, the paper sheds light on the temporary use of vacant spaces as a way to effectively create outcomes. In addition, the paper addresses the paradox of temporary co-production and the creation of lasting outcomes. Finally, the framework presented offers a tool for analysts and practitioners to take into account various conditions for co-production to create lasting effects.