Abstract. Urban Living Labs have become a popular instrument to find solutions to the pressing challenge that cities face: How can they combine economic prosperity, social cohesion, and environmental sustainability? While the normalisation of Urban Living Labs in cities is well evident to date, a lack of understanding in the nature and purpose of the empirical phenomenon leaves open many challenges yet to be overcome. One particular challenge is about their potential impact to contribute to transformative changes. By combining a retrospective historical literature review with a comparative case study to three Urban Living Labs in the city of Groningen, the Netherlands, this study explores how the triadic relationship between stakeholder roles, funding options and outcomes generated influences the impact creation of Urban Living Labs. The study confirms and adds to current theoretical positions taken about how to overcome issues regarding impact creation in terms of a shared ideology and reviewing the concept of power. Also, it shows that opportunity lies within trust building among stakeholders in Urban Living Labs in order to enhance its potential via five ways: redesigning funding programs, look out for new ways to access effectiveness, political empowerment of initiators, the level of abstract as facilitator in collaboration, and a clarification of the concept itself. Consequently, further research must focus on the social adoption and ownership of ULLs for sustainability and long-term impact, especially in local contexts, and how to make them self-sustaining and less dependent on external funding streams, like municipal subsidies.