Recent research work carried out in France tends to show that calling on collectives of artists or architects to develop participatory approaches with inhabitants has become a common practice for public or private project owners. However, these interventions are still often limited to communication operations or come up against the inertia of political and professional cultures, which limits their scope. After briefly stating the circumstances that lead urban project owners in France to pay increasing attention to the skills of architectural “collectives”, this article focuses on the presentation of two experiments conducted by two of them. Articulating pedagogical and urban citizenship issues, these experiments were confronted with procedural and normative frameworks, some of which came from the world of urban production, others from the school institution. The aim of this article is to show that the coproduction of spaces that have a strong meaning for their users, but which are unthought of within strategic urban projects, can have a greater impact on the way in which the operational actors envisage their project. After summarizing the main highlights of these two experiments, this contribution discusses the lessons that can be drawn from them in terms of their implementation conditions and the extensions they may have had. From a methodological point of view, the interest of these two experiments lies in the fact that the two associations that were involved in them understood them as experiments from the outset. They thus implemented reflexive mechanisms involving researchers, of which this article is one of the concrete results.