Book excerpt: All cities face a pressing challenge – how can they provide economic prosperity and social cohesion while achieving environmental sustainability? In response, new collaborations are emerging in the form of urban living labs – sites devised to design, test and learn from social and technical innovation in real time. The aim of this volume is to examine, inform and advance the governance of sustainability transitions through urban living labs. Notably, urban living labs are proliferating rapidly across the globe as a means through which public and private actors are testing innovations in buildings, transport and energy systems. Yet despite the experimentation taking place on the ground, we lack systematic learning and international comparison across urban and national contexts about their impacts and effectiveness. We have limited knowledge on how good practice can be scaled up to achieve the transformative change required. This book brings together leading international researchers within a systematic comparative framework for evaluating the design, practices and processes of urban living labs to enable the comparative analysis of their potential and limits. It provides new insights into the governance of urban sustainability and how to improve the design and implementation of urban living labs in order to realise their potential.