Against the increasing commodification of housing, a new kind of housing cooperatives has emerged in Catalonia in the last decade. These cooperatives fall within the wider concept of collaborative housing (CH), i.e. they are collectively self-organised projects based on a collaborative design process, or ‘co-design’. In such a process, residents need to adjust their individual expectations and demands in order to reach a collective set of values to realise their housing project. The aim of this paper is to assess how values are set through co-design and translated into a housing project. To do so, we develop an analytical framework to conduct a longitudinal single case-study that traces back the co-design process of the resident-led housing cooperative La Borda, in Barcelona. Our findings shed light on how co-design unfolds and uncover trade-offs carried out to overcome tensions mostly between individual and collective demands and between building costs and quality.