This historic document, prepared for the Department of Housing and Urban Development by the NBS' Institute for Applied Technology, is volume three of a three-volume study. Volume Three consists of supplementary documents provided by individuals and organizations under contract by the National Bureau of Standards for their expertise. The four supplementary documents and their authors are as follows: "The American Housing Production System," Drayton Bryant; "Performance-Based Space Criteria for Low-Cost Housing: Appendices A and B," University of Illinois; "The Role of Social Needs of the Urban Poor in Formulating Performance Standards for Housing," John Mascioni; "A Pilot Study of the Economies of Scale Related to Residential Construction," National Association of Home Builders.