The large size of collaborative housing projects allows for two major benefits. On the one hand, it reduces spatial particularisms, thereby allowing for a multiplicity of dwelling uses. On the other hand, the benefits generated by critical mass and the possibility to avoid others can favour social inclusion both within the project and in the neighbourhood. The paper is based on a cross-disciplinary study of collaborative housing projects developed at three different scales in Nantes (La Boîte Noire), Brussels (Brutopia) and Zurich (Kalkbreite). The analysis of the projects links a spatial investigation of the dwelling spaces with in-depth field observations to understand their actual uses. Given their greater spatial diversity and social mix, large-scale collaborative projects tend to offer more resilience towards domestic and societal changes. Size could hence be a valuable asset into new sustainable design, provided that some precautions are taken (ensuring solidarity despite heterogeneity, preventing oversize and enabling the cultural and legal conditions for alternative developments).