Collaborative housing as adaptive social infrastructure: Baugemeinschaften and neighbourhood engagement in Hamburg

This paper examines six Baugemeinschaften in Hamburg, Germany, as adaptive social infrastructure at the neighbourhood scale. Drawing on semi-structured interviews with residents and experts, supplemented by site observations, it analyses how collaborative housing projects engage with surrounding neighbourhoods, and which factors enable or constrain such engagement. The results show that neighbourhood openness depends on the interaction of residents’ pro-engagement attitudes, group management capacities, neighbourhood context, and the accessibility and design of common spaces. The paper contributes to urban design debates by showing how collaborative housing can create adaptable, semi-public social infrastructure, while cautioning that inclusiveness is contingent rather than automatic.