He is best-known for his concept of separating the physical infrastructure of buildings into support and infill, developed in the book Supports: An Alternative to Mass Housing, which was first published in 1961. Supports advocated an approach where the State provided the infrastructure on top of and between which people could build their own housing, influenced in some respects by the work of the Megastructuralists. Habraken took this further as director of the Foundation for Architectural Research (SAR) which investigated the use of industrial manufacturing in mass housing and looked at the role of architects within this.