The concept of ‘publicness’ addresses the intersection between people and their physical surroundings, and the ways in which they affect each other in an ongoing process. This point of relational exchange is the core concept behind ‘Public Space in European Social Housing’ (PuSH), a three-year HERA-funded project conducted by a transnational, multidisciplinary team of researchers. Large-scale modernist postwar housing estates, often used for social, cooperative, or mass rental housing, tend to be problematised as places of segregation and disintegration in European cities. Yet they are potentially also primary sites for integration between people of different cultural origins and social backgrounds. By investigating publicness in relation to social housing, including cooperative housing and mass rental housing estates, PuSH aims to better understand how cultural encounters happen, and ultimately to reflect on how integration can be better sustained. In this paper, we take a relational conception of publicness as our point of departure to explore the differentiations and intersections between sites and modes of public life in relation to our approach and the social housing estates we investigate. Moreover, we present our conceptual contribution to the concept of publicness, both theoretically and methodologically using multidisciplinary theories and methodologies, and four analytical categories: heritage, practices/policies, democracy, informality, and moreover exhibitions are used as a research tool. This paper is a collaborative output whereby different researchers on the project present their theoretical developments and positions, identify the analytical categories and theoretical vocabularies on which they daw, and reflect on potential ways in which these concepts can be operationalised, and on the synergies that may develop between them. Taken together, our approach offers significant interpretations of publicness in relation to questions of public space, and tackles some of the most pronounced tensions in discussions of public space.