Prefabrication experiments - 88 - Komendant's pre-stressed modular building

It has been documented by architectural and construction historians that engineers were the first to explore the new materials and processes generated by the industrial revolution. Engineers helped forge many of the industrial city's archetypal structures: bridges and towers, rail stations, tall commercial buildings and industrial hangars all developed with the emerging manufacturing knowledge for iron, steel and reinforced concrete.

Engineering’s contribution to modernity was remarkable and notably highlighted by the invention of steel reinforced concrete systems for building. Whether the Kahn Truss system of reinforcement developed in the U.S.A. or the Hennebique system devised in France, these early 20th century engineers and their initiatives were central in reforming building techniques. Engineers were and remain an important part of architecture’s creative process.

Within this tradition, August E. Komendant’s work as a structural engineer helped stimulate innovation in construction, engineering and architecture. Komendant was educated in Germany and practised mostly in the United States after World War II. He is well-known for his lasting collaboration with Louis Kahn and his work on Moshe Safdie’s Habitat 67 prototype for the Man and his World Universal Exhibit held in Montreal, Canada in 1967. Both collaborations, with Kahn and Safdie, produced buildings synonymous with 20th century modernity.

Komendant's research in reinforced concrete was pioneering and is exemplified by his experiments in modular building aimed to improve construction in matters of efficiency, strength and quality. His patented Modular Multi-floor Building was composed of rectangular prisms cast on site and stacked vertically between horizontal floor slabs.

The distinctively inventive portion of Komendant’s strategy was that each extruded rectangular prism was not only stacked over the floor slabs as in a simple building block strategy, but each prism was stitched vertically through holes in the prisms’ walls and floor slabs with tension cables. Each cable passed through slabs and walls and would then be stressed to create a taut sandwich effect between all the system’s components. This post-tension pre-stressed system produced greater strength and rigidity and optimized concrete’s structural efficiency. The overall structural strategy produced a rigid waffle type edge slab building, which could be cast on site reducing the inconveniences linked to transporting heavy prefabricated concrete systems.

Patent drawing dated April 1, 1980

Prefabrication experiments - 87 - M.I.T.'s glass fibre reinforced plastic roof structure

Plastics are a relatively new material in the history of construction. Although natural resins and polymers have been used since ancient times, the chemical compounds associated with modern plastics were dependent on the advances made during the late 19th and early 20th centuries. As new processes and methods moved from military use to the mainstream, experiments with these light and resistant composites changed existing construction materials and developed new ones. Plywood was one of the groundbreaking uses for polymer resins. Additionally these compounds gave way to plastics’ use in all building systems. 

In the mid 50s, Marvin E Goody and Frank J Hager from the Massachusetts Institute of Technology explored glass reinforced plastics for buildings. The MIT researchers united with industries such as Owens Corning to study new potentials for plastics in architecture. Their work led to an association with Monsanto on the «all plastic house of the future» exhibited by Disney from 1957 to 1967 and to a lesser-known project for a flexible school structure.

The monocoque shell skins for the Monsanto house helped develop an ideal form- resistant structural shape. The monocoque shells were lightweight and could be moulded into virtually any profile. In the case of their experimental elementary school the researchers developed a hyperbolic paraboloid (a curved surface shaped like a horse saddle) skin composed of a foam insulated core (25 mm) moulded between two thin fiberglass reinforced (1.5 mm) skins.

The «HyPar» shaped were arranged to form a completely open plan that could evolve according to changing social and academic needs. Each 2.4m x 2.4m square shell was bolted to a mast that supported four identical shells, which were also bolted together. The configuration created an uninterrupted modular 4.8m x 4.8m grid of posts that supported a by-directional ribbed surface. Each shell weighed ten times less than its concrete equivalent would for the same span.

Plastics presented the flexibility of concrete without the weight limitations. Plastics’ flexibility was emblematic of modern society’s main constituent: the need for constant change. Social paradigms were being challenged at an alarming rate. Research in Architecture and building technology paralleled this social development, as systems’ flexibility became a focal point for exploration.

Experimental School - Ribbed modular «Hypar» glass fibre reinforced roof panels

Prefabrication experiments - 86 - Kunio Maekawa's PREMOS

Post World War II housing developments in the United States were characterised by on-site standardisation of construction and the politics of accessible procurement methods.  Developers such as William J Levitt were successful as they controlled purchasing and construction. The small American single-family dwelling drove this type of standardisation and propelled the industrialisation of specific components rather than the manufacturing of complete buildings. As this type of development became the model in North America, Europe, Scandinavia, the Soviet Union, and Japan were coping with their own housing crisis. War reparations, rebuilding and restructuring were pushing for new models of development in every country.

Underwritten by governments, housing programs characterized the post war housing industry and showcased potential for innovative cross breeding of architecture, housing and industry. Japan for instance had lost over thirty percent of its housing stock during the war and looked to quickly restock and imagine productive ways to rebuild. Industry was a major component of the rebuilding programs. Intensely, wartime industries were commanded to serve the civilian economy. This was the case in many countries and the foundation of a manufactured building partnership in Japan.

Kunio Maekawa, a disciple of Le Corbusier who had also interned for the Wright inspired architect Antonin Raymond brought the modernist dream of the factory made house to Japan. The Manchurian Aircraft Company was repurposed for housing after it had closed down following the war. PREMOS - Prefabricated Maekawa Ono Kaoru San'in Manufacturing was the result of this ambitious project, which united Industry, academia (Kaoru Ono, Tokyo University) and Maekawa’s aspiration. The company produced its first standardised panelized structure in 1946 and led to over one thousand units before the company shut down in 1952.

The flagship unit, PREMOS 7 presented an area of fifty-two square meters and a simple wood construction building system that combined Honeycomb panels and plywood sheeting with wood trusses for floors and roofs. The PREMOS design standards followed Japan’s long history of standardisation in planning. The Ken, a standard dimension of precut wood in Japanese construction, and the tatami mat contribute to a modular heritage that ingrain standardisation and make it the social norm. The PREMOS project was the forerunner of the thriving contemporary prefab industry in Japan.

Premos 7 - components