ALUMINUM

Aluminum is such a ubiquitous material in 20th-century architecture that it is hard to
appreciate how relatively late it came on to the scene. Aluminum had considerable
advantages, including its light weight, its malleability, its corrosion resistance, and its
alloyability for special properties. For the first third of the 20th century, however, it had
to compete with similarly reliable materials, especially steel. Nevertheless, aluminum
was seen as a thoroughly modern material without historical associations, making it
indispensable to the Modern movement. This did not preclude some designers from using
the material for historicist styles, but its functional role in architecture kept pace with
architectural design and building technology.
The particular strengths of aluminum were proven during World War II in a wide
range of applications. However, after the war, the primary producers put aluminum into
large-scale market development to advocate for its use in all sectors, architecture being
no exception. In fact, by 1965 an estimated 905,000 tons of aluminum were used in
building construction in the United States, more than in any other field of application.
Aluminum’s most significant and specific contributions to 20th-century architecture have
been in windows, storefronts, and curtain walling. Aluminum has also been widely
employed in decorative features and hardware, windows and doors, and siding for a range
of structures.
Although aluminum had been known for much of the 19th century, one of its first
architectural uses was for the capping of the Washington Monument (Robert Mills,
1884). Aluminum was introduced commercially after 1886, when American Charles Hall
and Frenchman Paul Héroult independently and almost simultaneously discovered that
alumina, or aluminum oxide, would dissolve in fused cryolite, which could then be
decomposed electrolytically to become a crude molten metal. A low-cost technique, the
Hall-Héroult process remains as the major method used for the commercial production of
aluminum.
Another early application of aluminum in architecture came in 1891, when Burnham
and Root used the material for the interior fittings of the Monadnock Building (1889–91)
in Chicago. In 1897 Raffaele Ingami used unalloyed aluminum sheets with aluminum
rivets to surface the cupola of the Church of San Gioacchino (1897) in Rome. In the same
year in Montreal, the Canada Life Building (Brown and Vallance, 1897) was finished
with a decorative aluminum cornice. In all these cases, the metal was used as a practical
substitute and did not contribute significantly to the design.
The Austrian Otto Wagner developed the use of aluminum as a deliberate and specific
architectural feature in his Post Office Savings Bank (1904–06) in Vienna. He used
aluminum bolts to hold the exterior marble panels, and he used aluminum for interior
cladding and details, such as the grilles and vents. Although it would be some 30 years
before the material came into the mainstream of architecture, Wagner’s designs
represented a breakthrough and began to establish aluminum as a modern material, one
that could be associated with the ideals of modern architecture, including technology and
theories of modernism.
Despite these early precedents, aluminum’s large-scale application as a constructive
and decorative architectural material was developed most significantly during the 1930s.
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Even in Pittsburgh, the aluminum capital of the United States, the tower of the Smithfield
United Church (Henry Hornbostel, 1926) used aluminum, but still only as a substitute for
other metals and in a design that was strangely traditional and imitative.
Modernist architects began to value aluminum as a building material with vast
potential. With the development of steelframed skyscrapers and curtain walls, architects
used aluminum for glazing bars and spandrels. Aluminum could save space, reduce
weight, and shorten building time. Aluminum’s strengthto-weight ratio meant that thinner
and lighter sections could be used for spandrels and windows, thus significantly
increasing rentable floor area. In addition, these elements could be prefabricated and
hoisted into position on-site, thus saving considerable time and money over conventional
materials. These factors were directly related to considerations of industrial building and
mass production of component parts. Many skyscrapers were fitted with aluminum
spandrels in the 1930s, including the panels of the Empire State Building (Shreve, Lamb
and Harmon, 1930). The Daily Express Building (1931) on London’s Fleet Street by Ellis
and Clarke combined glazing bars with glass panels. Another noteworthy use of
aluminum was in the fabrication of storefronts and window frames. During the 1930s, the
American Kawneer Company developed extrusion technology that was particularly
appropriate for fabricating metal windows and storefronts. The combination of reduced
maintenance, technical efficiency, and ease of assembly encouraged the use of
prefabricated aluminum components.
These applications to commercial buildings were paralleled by experiments in housing
and space frame architecture. In 1931 the Aluminaire House was erected by Lawrence
Kocher and Albert Frey as a demonstration building within the Allied Arts and Building
Products Exhibition in New York City.
The house was built using aluminum-pipe
columns and panels fixed on the interior frame with screws and washers. The Aluminum Company of America subsidized
the aluminum parts, probably with the intention of developing another area of aluminum
application. In the late 1920s, Buckminster Fuller intended his 4D house to be fabricated
from aluminum alloys, which at that time were yet to be developed. By the early 1930s,
new heat-treated alloys were available, yet Fuller’s experimental ideas were not accepted
by the American Institute of Architects (AIA), where prefabrication in domestic building
was disfavored. These early attempts at prefabrication did nonetheless set a precedent for
later postwar architects who produced a range of prefabricated buildings that employed
aluminum in many different applications.
This potential for prefabrication and portability was developed after World War II. For
example, the British aircraft industry produced 86,000 prefabricated bungalows using
aluminum as the main material immediately after 1945, and in America after 1940 the
National Homes Corporation designed and manufactured prefabricated houses using
aluminum cladding and roofing. The prefabrication ideal was also used in England for
schools and portable buildings. During the 1950s, a British firm developed the supply of
prefabricated, pressed, aluminumframed huts for use in rural areas of Africa.
After World War II the aluminum companies began promoting their material for use in
construction and architecture. In 1947 the R.S. Reynolds Company, a specialist
aluminum supplier, set up a Memorial Award, which was offered by the AIA for
architects who “made the most significant contribution to the use of aluminum
aesthetically or structurally, in the building field.” Notable examples of award winners
include I.M.Pei’s 88 Pine St., New York (1974), Philip Johnson’s Pennzoil Place (1978),
Foster and Partner Hong Kong Shanghai Bank Headquarters (1986), and Helmut Jahn’s
United Airlines Terminal, Chicago (1988). In France, the work of Jean Prouvé (who had
already developed an interest in aluminum prior to 1940) was greatly enhanced when, in
1949, the French trade association L’aluminium Français purchased an interest in his
workshop. He used aluminum curtain walls for the Féderation Nationale du Bâtiment
building in Paris and continued to develop aluminum components for commercial,
residential, and overseas commissions.
The demand for “space frames” grew with a demand for exhibition halls, aircraft
hangars, warehouses, and storage facilities. One of the most elegant solutions for space
frames was the dome. The Festival of Britain’s Dome of Discovery (1951) was fabricated
mainly from extruded triangular lattice aluminum framework and, at a span of 110
meters, was the largest aluminum structure at the time. By the later 1950s, the American
Kaiser Aluminum Corporation was developing a prefabricated dome system that use
shaped panels to create domed space frames. Structures, with a diameter of 145 feet and
able to hold up to 2,000 people, could be erected in a matter of hours. A gold-anodized
Kaiser dome was erected in Moscow in 1959 for a U.S. cultural and industrial exhibition.
Although these structural uses of aluminum were impressive, the most successful
postwar application was undoubtedly the further development of the curtain wall. The
aluminum-clad 30-story Alcoa Building (1950) in Pittsburgh by Harrison and
Abramovitz was the lightest permanent office building of its size in the world at one time
and required approximately less than half the constructional material of a similar building
that used structural steel in the framework. In Chicago, where skyscraper curtain walls of
the post-World War II era consisted of stainless steel, rusting steel, and glass, Naess &
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Murphy’s Prudential Building (1955) was significant not only for its temporary status as
the city’s tallest building but also for its limestone and aluminum facade.
Modern Japanese architects have also embraced the material. Arata Isozaki’s
Prefectural Museum of Modern Art (1971–74) in Gunma and the Museum of
Contemporary Art (1981–86) in Los Angeles make extensive use of aluminum panels.
The use of aluminum as a component in the structure of buildings continued in the 1970s,
especially as an element of High-Tech style. The works of Norman Foster, including the
Sainsbury Centre for the Visual Arts (1977) at the University of East Anglia and his
Hong Kong and Shanghai Bank (1985); parts of the Lloyds Building (1979–87) in
London by Richard Rogers; and the outer frameworks of I.M.Pei’s Bank of China (1990)
in Hong Kong exemplify this trend.
Aluminum is now a standard and unexceptional material for buildings. It has been
specified for cladding, roofing, and interior applications of all kinds, including partitions,
ceilings, ducting and trunking, grilles, and hardware fittings, including gates grills,
balcony rails, lamp casings, and ornamental and practical fittings of all kinds.