Several approaches to the concept of the common can be distinguished: a first approach is based on the triptych defined by Elinor Ostrom in terms of resources, communities and methods of regulation; a second focuses on the work of instituting praxis; a third revolves around the principle of guaranteeing access to useful resources; a fourth, finally, is understood as the framework of shared experience. The article proposes to study how these four approaches are opposed but above all how they complement each other, by embodying the argument in the case of participatory housing, defined as a process of pooling housing.