Steel is a material present in the structure of virtually all works of 20th-century architecture: in the connectors, plates, nails, bolts, and screws of timber floors and frames; in the deformed bars hidden within the cement and stone matrix of reinforced concrete; and in the hot-rolled wide-flange columns and beams characteristic of steel skeletal frameworks. Although its history as a building material can be traced back at least to the fifth century B.C., and although its potential to revolutionize the whole process and form of building was in many ways already evident in the 19th century, it is in the 20th century that the architectural expression of steel was most thoroughly explored.
Steel refers to any metal consisting primarily of iron, although the term is now commonly used in a more restrictive sense, reserved for the mild carbon steels that first appeared in the mid-19th century and the high-strength, corrosion-resistant (“weathering”), and stainless steels developed more recently. Cast- and wrought-iron products had been used extensively in building, especially in the 19th century, but were largely superseded by the beginning of the 20th century by hot-rolled steel members. The ultimate victory of steel over earlier forms of iron was the result of steel’s superior structural properties along with an increasingly efficient manufacturing process—based on the innovations of Bessemer, Siemens, Thomas, and others—that dramatically reduced its cost while increasing its output. Stimulated first by the needs of the railway industry in the mid-19th century and later by a dramatic increase in large-scale building projects, construction in steel became inextricably linked with the accelerated pace of commercial and industrial development in the 20th century.
The economic and social changes accompanying this development met with mixed reactions. Chicago architect Louis Sullivan found a kind of spiritual poetry in the steel frame’s aspiration for verticality; Italian futurist Sant’Elia proclaimed in 1914 that the steel bridges, railway stations, cars, and planes of the modern epoch already signaled a radical discontinuity with the traditional forms of the past; and Russian Constructivist Vladimir Tatlin’s proposal for a spiraling steel monument to the Third International in 1920 provided a dynamic and optimistic visual image for the new technology. Yet other artists and critics saw only the negative social consequences of the 20th century’s new steel-framed architecture: dark, canyonlike streets; anonymous, repetitive facades; and degrading or dangerous working conditions. Steel was not simply the material par excellence of the industrial revolution; at the dawn of the 20th century, it was also a potent symbol of economic power and monopolistic arrogance, personified in the legendary figures of Andrew Carnegie, J.P. Morgan, and Elbert H.Gary.
With the development of steel architecture, other formal and technical issues have emerged: reconciling requirements for fireproofing and corrosion protection with the desire for direct expression; exploiting the potential of standardization, prefabrication, and mass production; expressing the ideal of lightness and elegance or the tectonics of load and resistance; and incorpo-rating the image of the machine (whether derived from industry, transport, or war) or the influence of other aesthetic tendencies (from Constructivism to deconstruction). These issues are subsumed within the following discussion, which is based on three critical 20th-century building types: the office building, the long-span “shed,” and the house.
Chicago School architects pioneered the steel-framed office building in the late 19th century, and similarly important skyscrapers were designed in New York City and most major American urban centers. In New York, the 30-story Park Row Building (1898) was soon surpassed in height by a series of early-20th-century stone-clad, steel-framed towers, braced internally with diagonal trusswork or made rigid with riveted steel portal frames. The most influential of these buildings was the Woolworth Tower (1913). Designed by Cass Gilbert, it was the tallest building in the world at the time, having overtaken the 50-story Metropolitan Life Insurance Building (1909), designed by Nicholas Le Brun and Sons, which had just surpassed the 47-story Singer Building (1907), designed by Ernest Flagg. At the beginning of the Great Depression, two steelframed structures in New York City took skyscraper design to new heights, both literally and metaphorically: the Chrysler Building (1929) by William Van Allen and the Empire State Building (1931) by Shreve, Lamb, and Harmon. The Chrysler Building is notable in this context for its crown of stainless-steel cladding, one of the first extensive building applications for the newly invented steel alloy.
Critics have argued about the architectural significance of these New York skyscrapers and whether their exuberant facades of stone and brick—reminiscent in many cases of medieval towers and Renaissance campanile—adequately express the nature of modern steel construction. Although their effect as cultural icons is unquestioned, in general it is the earlier-19th-century Chicago School buildings of Sullivan, Root, Burnham, and Jenney that are cited as exemplars of steel-framed building and precursors of modern design. After World War II, architects generally eliminated cornices and other traditional decorative elements derived from historic architectural styles in favor of the unornamented, rectilinear geometry associated with 20th-century modernism. Even so, the expression of steel framing remained problematic. For example, in Mies van der Rohe and Philip Johnson’s Seagram Building (1958) in New York City, the actual steel structure is first encased in concrete fireproofing and then hidden behind a metal and glass curtain wall. Even with bronze I-beams applied on the facade to stiffen the vertical mullions, expression of the actual steel framework is, at best, indirect.
A more direct expression of steel structure is achieved by exposing the characteristic flanged shapes of actual painted or corrosion-resistant steel beams and columns or by celebrating the geometry of structural forms characteristic of steel—usually trussed or rigid frameworks evocative of steel industrial or civil engineering works. In the first case, Kevin Roche and John Dinkeloo’s use of exposed and unpainted corrosion-resistant steel girders for the Knights of Columbus Headquarters (1969) in New Haven, Connecticut, and Skidmore, Owings, and Merrill’s use of partially exposed painted steel girders (the flanges being covered for fire protection) in the U.S. Steel Building (1972) in New York City may serve as examples.
In the second case, the geometric form of truss or frame (rather than the shape of the individual elements) evokes steel structure. Three buildings by Skidmore, Owings, and Merrill illustrate this approach. The Inland Steel Building (1957) in Chicago expresses its welded-steel framework by locating the vertical elements of the framework outside the glass plane of the curtain wall, the Alcoa Building (1964) in San Francisco positions its triangulated steel bracing structure 18 inches in front of its glass curtain wall, and the Hancock Building (1970) in Chicago sets its steel trusswork into the plane of the facade. Two buildings in Hong Kong provide additional examples based on the same principle. The Bank of China (1990) by I.M. Pei selectively expresses the complex triangular geometry of its steel frame, suppressing the articulation of horizontal truss elements and thereby changing the apparent pattern of the framework on the facades from a series of Xs—which would have negative cultural connotations—to a series of diamonds. Norman Foster’s Hongkong and Shanghai Bank (1986) employs a more explicitly machinederived aesthetic, using tension elements to literally hang sections of the building—eight floors at a time—from steel trusses that in turn are cantilevered from mammoth steel columns. In these examples, the actual articulated steel structure is clad in sheet metal or, in the case of Pei’s triangulated framework, stone veneer. Steel “exoskeletons” may also be unclad, as at the Foundation Cartier (1994) in Paris by Jean Nouvel, where abstract planar surfaces of parallel curtain wall screens are contrasted with exposed angular steel frames designed to provide structural stability.
The use of steel for long-span roof structures has its roots in 19th-century bridges, train sheds, market halls, and exhibition spaces. Structures such as the Crystal Palace (1851) in London and the Galerie des Machines (1889) in Paris already showed the potential of iron (or steel, in the case of the Galerie). New functions requiring long-span roofs evolved in the 20th century, including hangars for airships and aircraft as well as singlelevel factories oriented toward the new flexible assembly-line production techniques pioneered in the automobile industry.
Long-span steel trusses, originating with 19th-century bridges (Benjamin Baker’s steel-truss Forth Bridge in Scotland was the world’s longest spanning structure at the time of its completion in 1890) were used in numerous factories and other building types to create large, column-free interior spaces. Albert Kahn’s Glenn Martin Aircraft Plant (1937) in Middle River, Maryland, is of interest not only because its 300-foot (91-meter) trusses created the largest flat-roof span attempted up to that time but also because Mies van der Rohe used a photograph of its interior to construct his famous collaged image for a Concert Hall project, published in 1943. Additional representative examples in which steel parallel-chord, horizontal trusses are featured as important architectural elements include the New Haven Veterans Memorial Coliseum (1972) by Kevin Roche and John Dinkeloo, where exposed corrosion-resistant steel trusses carry a multilevel parking structure over the stadium below, and the McCormick Place Convention Center (1970) in Chicago by C.F.Murphy Associates, in which two perpendicular sets of parallel trusses are used. An unusual multistory application of long-span steel trusses can be seen at the Georges Pompidou Center (1977) by Renzo Piano and Richard Rogers, where the truss span—and therefore the required depth of the structure—is reduced through the use of sophisticated cast-steel “gerberettes” cantilevered inward from water-filled tubular steel columns to support the trusses, the columns being expressed on the building’s exterior along with tensioned steel rods and diagonal cross bracing.
Variations on steel-trussed arches and frames, providing lightweight and structurally efficient spans, can be seen in early20th-century hangars for airships (zeppelins) and factory buildings, especially in Germany. An early example, influenced by the threehinged steel arch forms of 19th-century bridge and exhibition structures, is Peter Behrens’s AEG Turbine Factory (1909) in Berlin, in which hinges and vertical elements making up the repetitive steel arches are expressed on the exterior of the side facade. Norman Foster’s Sainsbury Centre (1977) in Norwich, England, uses tubular steel-trussed rigid portal frames that contain the mechanical services for the building while providing a clear span for the display and academic functions within. A more complex three-hinged trussed arch appears in Nicholas Grimshaw’s Waterloo International Rail Terminal (1994) in London. There, the required asymmetry results in steel tension elements of the truss—expressed as thin rods—being located first above and then below the roof structure, creating a form at once rational and counterintuitive. A final example is the International Exhibition Center (1996) in Leipzig by Ian Ritchie, in which arched trusses with cast-steel support arms form an exoskeleton supporting the vaulted Main Hall.
Polyhedral-based structures—three-dimensional versions of simple planar trusses—were pioneered by Alexander Graham Bell in 1907 and developed into more sophisticated space frames by Max Mengeringhausen in Germany in the 1940s and Konrad Wachsmann in the United States in the 1950s. Buckminster Fuller invented the geodesic dome, based on the triangulation of a spherical surface, in the late 1940s. Steellamella roofs, consisting of intersecting, offset systems of parallel ribs, have been used in hangars, stadiums, and other long-span applications. Later—20th-century versions of these forms include the Javits Convention Center (1986) in New York City by I.M.Pei, consisting of a steel space frame used for both walls and roofs; Fuller’s geodesic dome for the U.S. Pavilion (1967) at the Montreal Expo; and the steel-lamella Louisiana Superdome (1975) by Sverdrup and Parcel Associates.
Long-span masted tension structures, inspired by 19th-century suspension bridge and 20th-century cable-stayed designs, use steel rods in tension to support horizontal roof surfaces. The Burgo Paper Mill (1962) in Mantua, Italy, by Pier Luigi Nervi quite literally mirrors the form of conventional suspension bridges to create clear-span spaces below its suspended roof. More recent masted steel structures exploit the same principles, although their forms have become less derivative of bridge design and more articulate in expressing the exposed-steel connections between tension rod, horizontal beam, and vertical mast. Notable examples by Richard Rogers include the Fleetguard Distribution Center (1979) in Quimper, France; the Inmos Microprocessor Factory (1982) in South Wales; and the PA Technology Laboratories (1985) in Princeton, New Jersey. Norman Foster’s Renault Distribution Center (1980) at Swindon, England, has a more complex geometry defined by perforated, tapered beams; masts; and tension rods. The Darling Harbour Exhibition Center (1988) in Sydney, Australia, by Philip Cox, Richardson, and Taylor makes reference, in its masted supports and steel outriggers, to the adjacent maritime harbor and its associated nautical motifs. The suppression of tension elements and the elaboration of the mast into compressive “treelike” structural forms—first systematically studied by Frei Otto—can be seen in several steel-framed projects by Santiago Calatrava, including the BCE Place Gallery (1992) in Toronto and the Oriente Station (1998) in Lisbon.
In tensioned-membrane structures, steel cables are combined with fabric membranes to create extremely lightweight, long-span structures. Frei Otto’s tent structures for the German Pavilion (1967) at the Montreal Expo and for the Munich Olympics (1972) are landmarks in the development of these forms. Two late-20th-century long-span examples are the Georgia Dome (1992) in Atlanta, engineered by Weidlinger Associates and based on a patented “tensegrity” geometry defined by triangulated steel tension cables and floating steel compression struts, and the Millennium Dome (1999) by Richard Rogers in which the dome—historically a compressive structure—is transformed into a tensioned membrane by hanging the steel cable net defining its domical surface from an array of twelve inclined steel masts that penetrate the membrane. Lightweight domical surfaces can also be formed with membranes by mechanically increasing the interior air pressure, as in a balloon: An early example of such a pneumatic structure, contained by a net of steel cables, is the American Pavilion at the Osaka Expo (1970) by Davis Brody Associates.
With the development of welded connections—first invented in the late 19th century but not used in buildings until the 1920s—steel beams and frames could more readily be designed within the modernist syntax of interpenetrating line and surface, uninterrupted by gusset plates, bolts, or rivets. The buildings of Mies van der Rohe at the Illinois Institute of Technology in Chicago illustrate this type of abstract welded-steel expression, most dramatically in the exposed parallel portal frames of Crown Hall (1956). Later projects from the 1960s and 1970s, influenced by Mies’s work, include Roche and Dinkeloo’s Cummins Engine Company plant (1966) at Darlington, England; the Reliance Controls plant (1966) at Swindon, England, by Team 4 (including Norman Foster and Richard Rogers); and Skidmore, Owings, and Merrill’s Republic Newspaper Plant (1971) at Columbus, Indiana. Functional requirements—for example, the need for daylighting in the immense new factory buildings of the steel, automotive, and aircraft industries— could also be addressed using welded-steel frames, angled or stepped to accommodate monitor skylights. Such bent frames can be found in Albert Kahn’s Chrysler Half-Ton Truck Plant (1937) in Detroit and, more recently, in Helmut Jahn’s Terminal One Complex for United Airlines (1987) in Chicago, the latter project using clusters of tubular steel columns supporting perforated steel beams that define skylit, linear public circulation spaces within the terminal. Curved, welded ribbed frames are used at an even more monumental scale in Rafael Viñoly’s Tokyo International Forum (1996), defining an immense elliptical tied-arch roof supported by two centrifugally spun steel pipe columns 400 feet (124 meters) apart.
The use of steel in the construction of factories, train sheds, market halls, and office buildings parallels the development of 19th- and 20th-century industry and commerce. The use of steel in 20th-century residential design has less of an objective basis, despite Le Corbusier’s famous aphorism defining the modern house as a “machine for living in.” Although steel-based technology was critical to the production of cars, trains, airships, and airplanes, attempts to design mass-produced, prefabricated, standardized, and flexible kits of steel parts applicable to the production of houses were generally less successful. In fact, although at least one fireproof steel residence—the Reid House (1894) in Chicago by Beers, Clay, and Dutton—was constructed before the 20th century, ambivalence about the appropriateness of exposed steel within the domestic sphere, as well as its relatively high cost compared with traditional residential construction systems, delayed the first applications of steel framing to residential construction. An experimental steel-framed house was produced for the German Bauhaus Exhibition of 1923 by painter Georg Muche and Adolf Meyer, but this house, along with a subsequent design completed in 1927, had little lasting influence.
The first truly influential steel-framed houses, built on both sides of the Atlantic Ocean at the end of the 1920s, rely for their expressive power on the juxtaposition of steel framing with large surfaces of glass. Among the most important are Richard Neutra’s Lovell Health House (1929) in Los Angeles; Pierre Chareau’s Maison de Verre (1932) in Paris; Mies van der Rohe’s Tugendhat House (1930) in Brno, Czechoslovakia; and Leendert Cornelis van der Vlugt’s van der Leeuw House (1929) in Rotterdam. Whereas Chareau has made the specific character of rolled steel—the flanged column shapes andthe bolted and riveted connections—an integral part of his architectural expression, Neutra’s steel frame is integrated into a more abstract gridded composition of glass and cement, visible only on the exterior of the house, where the closely spaced vertical members of the steel framework are selectively exposed as window mullions or supports for projecting rooms and balconies. In Mies’ Tugendhat House, similar in its detailing and expression to the better known German Pavilion (1929) designed for the World Exhibition at Barcelona the previous year, the actual bolted-steel framework is never truly revealed. Instead, only the grid of columns, clad in chromium-plated sheet steel and set didactically between abstract planes of floor and roof, can be seen. The van der Leeuw House is perhaps the most literally “machinelike” of all, boasting a whole array of electronic gadgetry and controls within a structure based on four parallel steel frames that penetrated the house from front to back.
A different tendency can be seen in the polygonal Dymaxion House (1927), designed by Buckminster Fuller, in which a rigorous analysis of functionality and structural efficiency is combined with an interest in mass production at low cost, unfettered by the aesthetic preoccupations of the European modernists. Fuller refined the design during the 1930s and 1940s and found manufacturers to build prototypes but was unable to implement the idea commercially on a large scale.
During the period immediately after World War II, especially in the United States, steel was vigorously promoted as a material suitable for residential construction. John Entenza’s Art & Architecture magazine published a series of so-called Case Study houses, the most influential of which was designed by Charles and Ray Eames for themselves in Pacific Palisades, California. The Eames House (1949) pioneered an aesthetic derived from the assembly of off-the-shelf, mass-produced, standard steel elements: open-web steel joists, corrugated-steel decking, and rolled-steel-column sections.
Two non-Californian steel-framed houses designed in the late 1940s were also extremely influential. Mies van der Rohe’s Farnsworth House (1951) in Plano, Illinois, and Philip Johnson’s Glass House (1949) in New Canaan, Connecticut, evince less concern with issues of economy, standardization, and mass production and more interest in exploring the formal qualities of the rectangular glass box within a welded-steel frame. The Farnsworth House was designed with its horizontal steel-framed floor and roof planes cantilevered outward from within two rows of external steel columns, raising the house off the ground. Johnson, however, by placing his Glass House directly on the ground with no cantilevered elements and by positioning his black-painted steel columns inside the glass plane, has shifted the emphasis from the steel frame to the glass enclosure.
Many postwar steel houses combine in various degrees formal qualities associated with the work of Eames and Mies. Influential Californian Case Study houses, such as Raphael Soriano’s Olds House (1950) in Pacific Palisades, Craig Ellwood’s Bailey House (1958) in Los Angeles, and Pierre Koenig’s Stahl House (1960) in Los Angeles, all are based on rectilinear grids of steel columns, with steel beams and corrugated-steel roof decks completing the framing schemes and largely defining the formal vocabulary. Beginning in the mid-1950s, modern steel houses began to be built in England as well, including Michael Manser’s Capel Manor House (Kent, 1970), the Richard Horden house (Dorset,1975), the John Winter house (1969) in London, and Ian Ritchie’s Eagle Rock House (1982) in East Sussex. Soriano, in particular, has been an influential figure for both British and American architects building in steel. Having experimented with lightweight steel trusses, beams, and columns since the late 1930s, he lent a certain credibility to the well-publicized but still largely unrealized ideal of industrialized building based on modularity, standardization, and prefabrication.
Interest in industrialized building—for housing, schools, and other building types—has been a continuous current in architectural thought for most of the 20th century. Early research into the mass production of lightweight steel structures, on the model of automobile production, can be seen in the work of Jean Prouvé and Buckminster Fuller from the 1920s and 1930s. Several industrialized steel systems for schools were implemented in the period after World War II, most notably the Hertfordshire County Council and CLASP systems in Britain in the 1940s and 1950s and the School Construction System Development Program in California led by Ezra Ehrenkrantz during the 1960s. By the end of the century, industrialized products were routinely used in a variety of applications, ranging from metal building systems—consisting of heavy steel frames with corrugated-steel cladding—to complete “volumetric” steel-framed housing units, the latter accounting for a small but growing proportion of total new home construction in Japan.
Steel-based industrialized housing systems were developed in Britain, the United States, and France in the aftermath of World War II, including several designed by Prouvé in the 1940s based on his earlier use of bent steel sheet in his Pavillion Démontable (1939). Jerry Wells and Fred Koetter continued research into the potential of light-gauge, cold-formed sheet steel for modular housing (1971), as did Cedric Price in the same year. Other experimental steel-based building systems designed in the 1970s and 1980s include Helmut Schulitz’s “Team for Experimental Systems and Building Techniques” (TEST) at the University of California, Michael Hopkins’s Patera System in Britain, Gunter Hübner and Frank Huster’s prototype housing system in Germany, Renzo Piano’s experimental houses in Italy, and Michiel Cohen and Jan Pesman’s Heiwo system in the Netherlands. However, these industrialized building attempts were only partially successful, with houses produced often only as prototypes, occasionally in limited numbers, and sometimes not at all.
Notwithstanding the limited application of steel-framed industrialized building systems to housing, the use of prefabricated, industrial steel elements has had a notable effect on later-20th-century residential architecture. In particular, an ad hoc and idiosyncratic use of corrugated-steel panels for roofing and siding can be seen in the provocative residential work of Frank Gehry, beginning with his Davis Studio/Residence (1968–72) in Malibu, California, and including the first addition to his own house (1978) in Santa Monica, California. The Australian architect Glenn Murcutt has also used corrugated steel and steel framing as crucial elements in many of his residential designs, including the Marie Short House (1975) in New South Wales and the Ball-Eastaway House and Studio (1983) in Glenorie, Sidney. Where the raw, industrial quality of steel cladding in Gehry’s work reinforces a sense of displacement already evident in the deliberately fragmented or truncated forms of his structures, Murcutt’s use of the same material achieves an opposite effect, imparting what has been described as a sense of dignity tothe corrugated surfaces.
Steel as Skin
Steel appears in architecture primarily as structure, but it is also used as nonstructural cladding, or “skin.” Gehry’s corrugatedsteel panels and the Chrysler Building’s stainlesssteel crown have already been noted. Other representative examples include Jean Prouvé’s innovative sheet-steel curtain wall for the Maison du Peuple (1939) at Clichy, France; Skidmore, Owings, and Merrill’s stainless-steel mullions at Lever House (1953) in New York City; Harrison and Abramovitz’s textured panels of stainless steel for the Socony Mobil Building (1955) in New York City; Richard Meier’s gridded porcelain enamel steel panels at the Athenium (1979) in New Harmony, Indiana; and Frank Gehry’s overlapping galvanized-steel sheet cladding at the California Aerospace Museum (1984) in Los Angeles.
The uniqueness of steel sheet and plate also manifests itself in a group of idiosyncratic structures not easily categorized by function or formal type but having in common a kind of sculptural presence in which distinctions between structure and skin become less clear. Eero Saarinen’s 630-foot (190-meter)-high Gateway Arch (1965) in St. Louis uses a double layer of steel, with quarter-inch (six-millimeter) stainless-steel plate forming the outside layer, as both cladding and structure. Le Corbusier’s pavilion for Heidi Weber (1967) in Zurich, based on his earlier steel project for the “Saison de l’eau” at the Exposition de Liegè (1939), contains an angular sheet-steel roof cantilevered from a series of steel piers and detached from but covering a rectilinear steel structure below. Bernard Tschumi’s abstract, orthogonal sculptural “follies” and expressionistic “gallery” structures within the Parc de la Villette (1982) in Paris provide a final example based on the use of both painted and porcelain-coated sheet steel.
Sennott R.S. Encyclopedia of twentieth century architecture, Vol.3 (P-Z). Fitzroy Dearborn., 2005.