Today, the evident need for more efficient conservation, management and redistribution of natural and human-made common resources have inspired thinkers, researchers, and designers to redefine the organization of our societies. For example, Silke Helfrich and David Bollier argue that the common-pool resources (CPR) defined by Elinor Ostrom require new "practices of commoning" that reconsider the conventional discourses of market economy and state intervention. Several contemporary architectural firms have introduced innovative design strategies concerning the collective collection and reuse of local materials, the commons and the circular economy.However, already after the oil crisis in the early 1970s, practices like the Secondary Reuse Group (SUG) engaged with circular reuse of materials but did not correlate to discourses concerning the commons. This essay analyzes SUG's projects during the 1970s using a lens calibrated on the contemporary debate of the commons, to unveil and highlight some relevant aspects of their work. This lens will refer to Michel Bauwens and Tom Avermaete who differentiate between material commons, that is, human-made and -handled reserves of materials from our environments and cities; immaterial commons, knowledge and craft skills existing in a particular place; and commoning processes, social practices of mutual collaboration. The first goal of this research is to describe the work of SUG concerning its material and immaterial commons. The second goal is to inform the contemporary debate regarding waste and materials as a CPR to be unlocked by architects and users through commoning processes of materials reuse.