In this chapter, we analyse the historical role of community norms and sharing ideas in the Swedish housing market as part of industrial transformation processes. We compare the emergence of a new organizational form, the housing cooperative, from the 1930s and onwards with the rise of the contemporary digital platform-based sharing economy. In the past, housing cooperatives were used to share the burden of risk between individual citizens, whereas contemporary sharing platforms allow for sharing the burden of ownership in cities with soaring housing prices. We ask if and how the role of community norms and sharing practices have changed over the last century and who was involved in transforming the housing market. We draw on rich historical secondary sources on the development of housing cooperatives as part of the Swedish model as well as on contemporary debate about the impact of sharing economy actors, such as Airbnb, on the Swedish housing market. In drawing on a semantic analysis of official government investigations on the housing cooperatives, we show that community norms have played a vital part in the industrial transformation of the Swedish housing market, indicating that informal institutions endured while formal institutions have gone through major transformations.