Drawing on the case of Vienna, the article examines the role of third sector housing for social cohesion in the city. With the joint examination of an organisational and an institutional level of housing governance, the authors apply an interdisciplinary, multi-level research approach which aims at contributing to a comprehensive understanding of social cohesion as a contextualised phenomenon which requires place-based as well as structural (multi-level) solutions. Using a large-scale household survey and interviews with key informants, the analysis shows an ambiguous role housing cooperatives play for social cohesion: With the practice of "heme-oriented housing estates", non-profit housing returns to the traditional cooperative principle of Gemeinschaft. However, community cooperatives rather promote homogenous membership and thus, encompass the danger to establish cohesive islands that are cut off from the rest of the city. Furthermore, given the solidarity-based housing regime of Vienna, fostering bonding social capital on the neighbourhood level, might anyway just be an additional safeguarding mechanism for social cohesion. More important is the direct link between the micro-level of residents and the macro-level of urban housing policy. In this respect, cooperative housing represents a crucial intermediate level that strengthens the linking social capital of residents and provides opportunity structures for citizen participation. However, the increasing adoption of a corporate management orientation leads to a hollowing out of the cooperative principle of democratic member participation, reducing it to an informal and non-binding substitute. Thus, it is in the responsibility of both managements and residents to revitalise the existing democratic governance structures of cooperative housing before they will be completely dismantled by market liberalization and privatization. In contrast to other European cities, third sector housing in Vienna has the potential to give residents a voice beyond the neighbourhood and the field of housing. / Series: SRE - Discussion Papers