Research highlights • The majority of buildings are not designed by architects, but are the result of processes and decisions that involve multiple actors (construction regulations, technical and industrial innovations, social norms, and practices). • Does that mean that building practices without architects are more successful in satisfying the needs of users? What are the reasons for their success? Could architects learn from these alternative approaches to building design? • This paper addresses these questions by examining the case study of coree, self-constructed settlements built on the outskirts of Milan between the 1950s and 1960s, focusing on the corea of Cerchiarello in Pero. • By analysing the formal and spatial features of Cerchiarello, contextualised in the historical, economic, and social frameworks that generated it, the qualities of coree building practices will be examined. Accordingly, the working methods and the protagonists behind the genesis, consolidation, and evolution of the corea of Cerchiarello will be reconstructed and examined. • The hypothesis of this study is that architectural research and practice should consider non-authorial and co-produced architecture as relevant as “high” architecture because it has its own methods and characteristics, whereby it can adapt to the changing needs of its inhabitants and thus reinvent itself. Therefore, the investigation of the methods and processes of coree should increase understanding of post-World War II Milanese architecture, and contribute to the development of practices aimed at making the urban fabric adaptable.