The Architecture of Sir Norman Foster
by Joseph Giovannini
Architect and Critic
Sir Norman Foster is celebrated for designing buildings detailed with the finesse of a trapeze—daring and even majestic high-wire apparatuses of steel parts tensed between articulate joints. Whether in projects built for small English towns or outposts of the global economy, the technological imagery is so consistent that his approach amounts to both an architectural signature and a design paradigm.
Ironically, the poetics of structure in a Foster building—the forces, their convergence, the expression—are based on the prosaics of componentry. From the firm’s first years in the late 1960s, Foster Associates produced award-winning buildings put together systematically from off-the-shelf parts: the stock turn-buckles, cables, web joists and I- beams were assembled into structures at prices competitive with contractor buildings. The beauty of Foster’s structures was cool, and even tough in the way athletes exhibit grace under pressure. The designs are gymnastics frozen in steel—strong, taut, lean.
But people working today in Foster’s Commerzbank in Frankfurt appreciate the 53-story building for other reasons. Finished in 1997, the tallest office tower in Europe may project technological prowess, but occupants know the building better for its neighborly intimacies. The tower allows daily acts of freedom unusual for people confined to the closed environmental canisters that pass today for skyscrapers. Employees can meet for sandwiches and coffee in terraced gardens adjacent to their offices, enhanced by long vistas in nearly all directions. More remarkably, they can simply reach over and open a window to let in fresh air that will cross the floor and rise up through the flue-like atrium, to waft out windows lining other gardens spiraling up the tower. Natural cross ventilation may be a commonplace assumption in a house, but in high-rise architecture, where it has invariably been engineered out, the ordinary window is a tender mercy.
Breezes, an espresso and some chatter are the tip of a different kind of architectural iceberg—gentle, humanistic signs that Foster has predicated the Frankfurt tower on premises belied by the building’s urbane technological detachment. Lobby, skin and a logo crown are among the few sections of a high-rise left for the architect to design after the cost engineers and real estate consultants run their figures. As a building type, the high-rise is the most formulaic of all, a tightly wrapped package with an elevator core centered in a stack of pancake floors sealed off from the environment by a curtain wall. But at the Commerzbank, Foster rearranged the usual anatomy of a skyscraper. He moved the elevator core with its bathrooms and stairwells from the center, leaving it vacant for the 53 stories, and then triangulated the three sides of the tower around the atrium while carving four-story gardens out of each side. The terraces, each a small, vertically local park serving its district of offices, fosters a democratic sense of village-like community within the larger geography of the building. By redistributing the central core to the corners of the triangular plan, Foster broke up the normally monolithic mass of the point tower so that each facade varies from the others in height and volume.
Many successful architects accept the conceptual envelope of a given building type, perhaps pushing it in certain places, but Foster has dared rethink the whole package, including what he calls “the social dimension.” The Manchester-born architect first radicalized the morphology of the high-rise with the completion of the Hong Kong and Shanghai Banking Corporation building in 1986. At a time when many architects were figuring out how to slip classicized suits over the steel cage, Foster relegated the usual core of elevators to the corners of a four-poster scheme, liberating the center for a partial-height atrium. The building became a more porous structure with open plateaus on each floor that allowed easy expansion and contraction within column-free spaces. Foster designed the tower as a stack of bridge trusses supported at the ends by steel masts, and he kept the perimeter walls back from a revealed edge. He lifted the banking hall off the ground with a glass-bottomed underbelly that sheltered a public plaza whose angled escalators dramatize the entry.
Though simple in its systematicity, the 47-story cross section was rich and varied, with double-height stories regularly interspersed among single-height spaces. By building the structure from an assembly of parts that are not wrapped within a continuous skin, Foster opened what is usually a closed form, creating an armature of change—open, free-span decks filled with light and supplied with conduits for squadrons of mobile computers. He mixed notions of the point tower and office block with principles of the megastructure developed during the 1960s and 70s, in which fixed structure was conceived as a support system for changing configurations. Although the final use of the building remained only offices, Foster originally planned the tower as a small vertical city with restaurants, pool, gym and outdoor gardens. As built, an executive restaurant at the top overlooks a helipad, and the glass-roofed plaza has proved popular for demonstrations as well as picnics.
Foster is an architect of flexibility, and his instincts to design for the inevitability of change are rooted both in the unselfconscious factory sheds of England’s industrial revolution and in the modest steel Case Study Houses of Los Angeles by Pierre Koenig, Raphael Soriano, Craig Ellwood, and Charles and Ray Eames. While a student at Yale’s architecture school in the early 1960s, Foster found the direction he would pursue for most of his career in an industrialized, off-the-peg approach conceived to raise construction standards and minimize costs. In the 1960s such assumptions were common, but instead of following the idealism of Mies van der Rohe’s classicized steel structures, Foster pursued prefabrication. Rather than Mies’ godly joints, he preferred California details—that is, more casual connections often determined in the field without any attempt at abstract purity. The Los Angeles houses did not have the closure of Mies’ classical structures but were more open-ended and even ad hoc. Mies had cut such a wide swath that an architect of Foster’s generation had more creative room in adjacent territory, and Foster found his path in an architecture built up from parts rather than deduced from any sense of a perfectible whole. Instead of the Miesian temple, Foster adopted the Eamesian Tinker Toy model, which allowed a much looser, more spontaneous approach that also meant plans could be easily changed ...