The history of building research and technology at the National Bureau of Standards is as long as the history of the institution itself. The participation of the Bureau in the application of science and engineering to building materials and components played an early and important role in the development of steel and reinforced concrete as structural materials; in the understanding of the physics and chemistry of cement, lime and gypsum; in the evaluation of the fire properties of building components; in safe plumbing practices; in laboratory evaluation of the effects of weather on deterioration of building materials; and in measurement of the heat and sound transmission properties of building materials and constructions. The central and continuing objectives of the building research program are shown to be the development of new technical information and new measurement methods for building materials, components, and systems, and the application of this knowledge to the specifications for Federal procurement, to the national standards of the building industry, and to the building code structure of the nation. The Bureau has served as a major technical resource in three large-scale national efforts to accelerate the construction of economical and effective buildings for housing and commercial purposes. One of these efforts is currently in progress and is characterized by an emphasis on the design of buildings to meet the performance requirements of the user rather than through the specification of the properties of the materials used.