In Swedish policy, Universal design (UD) is implemented as a guiding principle. This paper explores the conditions for co-creation when authorities and civil society collaborate. The empirical basis comes from qualitative analysis of interviews, go-alongs, group discussions, and change-oriented workshops in three urban development projects concerning the re-design of public spaces and buildings in three Swedish cities. Collaboration between municipalities and local disability organisations was formal and established but different expectations of organisations’ capacity and opportunities for influence, caused misunderstandings and mistrust. Interpretation of personal disability experience entailed ambiguity concerning roles and legitimacy. Hence, this paper considers UD a collaborative process, operating beyond regulatory compliance, transcending conventional categorisations, and inspiring and fostering commitment of a diverse population. It concludes that disability experience should be integrated into design processes in an intersectional way, as one of many experiences. That is in line with the CRPD, regarding persons with disabilities as equals and as contributors to cohesion and community building. Such a process requires co-creation where equals contribute to the common process but also reflection on the goals of community participation, and recognizing the needs of personal support and interaction. Since co-creation is a multifaceted, sometimes confusing, and idealistic concept, this paper suggests clarity, distinguished roles, and training of visualization abilities. Constraints of organisational asymmetry and challenges of engaging participants must be considered for developing a realistic view of co-creation. However, openness for learning between and beyond specific projects may develop equitable collaboration. For mutual and sustainable learning, the future usage phase must inform the design process. This positions UD in relation to co-creation as both a space of design possibilities and a human rights concept for an ethically reflected practice.