A decade ago the first Urban Living Labs emerged, as spaces for multi-actor experimentation with novel approaches to the complex challenges that cities are facing. Experimentation in Urban Living Labs was seen by scholars as a way to generate sustainable innovations that stood the test of real-life conditions, and as a novel approach to urban governance of sustainable development. From the beginning, scholars were interested in scaling, mainstreaming and institutionalization of both the outcomes (sustainable innovations) and the process (governance by multi-actor experimentation and learning). In this paper, we focus on the second issue and address the question: to what extent have successful Urban Living Labs been institutionalized and become part of the sustainability governance repertoire of local governments? We answer this question based on a comparative case study of the Urban Living Labs in Antwerp (Belgium), Maastricht (Netherlands) and Heerlen (Netherlands), with particular attention to the institutional mechanisms determining the outcomes in the three cases.
