Compared to traditional organizations, a coworking organization needs to be clearly distinguished, recognized and identified in its environment. The question of legitimacy is therefore relevant for coworking spaces. We investigate their spatial practices through Lefebvre’s spatial triad, and how they affect their organizational legitimacy, in order to establish whether these practices support the values promoted by coworking organizations. Based on an ethno-architectural survey, interviews and an analysis of their websites, we focus on two main values promoted by the collaborative spaces we investigated: alternative modes of governance and sustainability. We found that their spatial practices did not fully align with these values. We introduce the concept of spatial legitimacy, and our ethno-architectural survey contributes in methodological terms to the analysis of spatial practices in the field of organizational studies.