Temporal challenges of building a circular city district through living-lab experiments.

Urban living lab (ULL) experiments are expected to create grounds for circular city transitions but their temporal dynamics remain understudied. This study investigates the linkages of a particular sanitation experiment to a long-term urban development trajectories in the Hiedanranta ULL in the City of Tampere, Finland. The ethnographical study focuses on the temporal matches and mismatches of three interrelated timescales affecting the transformative potential of the experiment: (1) the experiment’s life cycle, (2) the brownfield ULL and (3) the formal land-use planning of the future city district. Temporal analysis showed that the creation of transformative capacity requires a long development trajectory beyond a single experiment. In this case, the long-term development of R&D networks and the persistence and maturation of the ULL with its variety of co-developing experiments enabled experiment implementation; changed the city’s sustainability discourse; and nurtured prominent cross-sectoral initiative of a super block. However, further implementation of ULL innovations in urban planning has proven to be difficult without a clear orchestrator. Practical recommendations highlight the need to clarify the strategic role of the ULL in experimental governance, transparent ULL processes that support learning, and overcoming transition barriers in the rigid infrastructure sector.