The architects and engineers behind skyscrapers

Chicago invents the frame

William LeBaron Jenney was an engineer, not an artist. In 1885 he put up the Home Insurance Building in Chicago, 12 floors and 55 m, with the walls hung off an iron and steel skeleton instead of carrying the load. That is the whole idea, andthe credit is still argued over.

Jenney's office trained the next generation. Louis Sullivan asked what a building standing on a frame should look like, and answered with a tall shaft wrapped in cast-iron ornament he drew from plant forms; the Wainwright and Guaranty buildings are the clearest cases, andhis own page has the rest. Daniel Burnham ran the business end of it, producing the Reliance Building, the Flatiron Building and the Chicago plan of 1909 from the largest practice in the world.

New York takes the record

Cass Gilbert dressed the frame in Gothic stone. His Woolworth Building of 1913 reached 241 m and held the record for seventeen years, longer than any building since.

The race of 1930 produced two buildings and two reputations. William Van Alen won the record for theChrysler Building, 319m, by assembling its steel spire inside the shaft and jacking it through the roof once his rival had topped out. Walter Chrysler then refused his fee and he never worked at that level again. Shreve, Lamb and Harmon took the title eleven months later with theEmpire State Building, 381m and 102 floors, built in thirteen months. William Lamb worked from a brief about rentable square feet and elevator banks, and its setbacks are what the 1916 zoning law allowed;the Art Deco page explains it.

The glass box

Ludwig Mies van der Rohe arrived from Germany in 1938 and stripped the tall building back to structure and glass. His apartment slabs at 860-880 Lake Shore Drive in Chicago, 1951, are steel and window with nothing applied. The Seagram Building in New York, 1958, with Philip Johnson, set a bronze tower back behind an open plaza that other developers copied for zoning bonuses. Most postwar office towers descend from those two.

The engineer who made height cheap

Fazlur Rahman Khan is the most consequential person on this page and the least known outside the profession. Born in Dhaka in 1929, he came to Illinois on a Fulbright scholarship and joined Skidmore, Owings and Merrill in 1955. The problem he solved is economic: in a conventional frame the steel resisting wind grows faster than the height, so above roughly 40 floors the structure eats the rentable space that pays for it.

His answer was to treat the building as a hollow tube cantilevered out of the ground, with the stiffness in the perimeter where it does the most good. The Chestnut-DeWitt apartments of 1964 were the first framed tube. For the 100-floor John Hancock Center he added the giant diagonal X braces on the facade, a trussed tube carrying wind load straight to the corners. For theWillis Tower of 1973,442 m and 108 floors, he bundled nine square tubes and stopped them at different heights, which is whereits stepped shape comes from.

The tube systems cut the steel per square foot roughly in half. Khan also pushed the idea that the engineer belongs in the room while the shape is decided, and he worked that way with the architect Bruce Graham on both Chicago towers. He died in 1982 at 52, and almost every supertall built since uses a descendant of his structural logic.

Going global

Minoru Yamasaki designed the original World Trade Center, finished in 1973, as two framed tubes with narrow windows he chose partly because he was afraid of heights. I. M. Pei cut the Bank of China Tower in Hong Kong, 1990 and 367 m, into four triangular shafts of unequal height, engineered with Leslie Robertson. Cesar Pelli gave thePetronas Twin Towers an eight-pointed Islamic plan andthe spires that took the record off Chicago in 1998.

Norman Foster brought a British engineering tradition to the form, in the exposed hanging structure of the HSBC building in Hong Kong and the diagrid of 30 St Mary Axe in London. Renzo Piano's Shard, 2012 and about 310 m, is eight glass planes leaning inward without quite meeting at the top.

Adrian Smith led the design of theBurj Khalifa at SOM, 828 m and 163 floors, with Bill Baker as structural engineer. Baker's buttressed core is a hexagonal concrete spine braced by three wings, a Y in plan, so the tower stiffens itself in every direction without transferring columns. Smith left SOM in 2006 and his own firm carried the Jeddah Tower design forward, aimed past 1,000 m, with Thornton Tomasetti engineering it.Its own page has the cost and the decks.

Who builds them now

Supertall work concentrates in a handful of offices. SOM has designed more record holders than anyone, Gensler did the Shanghai Tower, Kohn Pedersen Fox has built heavily in China and London, and Foster + Partners works everywhere. Below them sit the structural engineers whose names rarely reach a press release: Arup, Thornton Tomasetti, WSP, Leslie E. Robertson Associates.

That list is almost entirely men, and mostly American and European men. It describes who has been allowed to design tall buildings, not who could. Zaha Hadid was the first woman to win the Pritzker Prize, in 2004, and her office built the Wangjing SOHO towers in Beijing, though her reputation rests more on museums. Jeanne Gang designed the 365 m St. Regis Chicago, the tallest building in the world designed by a woman. Those are a few names against a century of towers.

What the work pays

Designing skyscrapers is not a separate career with its own salary band. It is architecture or structural engineering practiced at a firm that gets the commissions, so the pay is a licensed architect's: roughly $70,000 early on in the United States, well into six figures for a design partner. Nobody earns a percentage of a tower, because the fee goes to the firm. The route is an accredited degree, internship hours and licensing exams, and then getting hired at one of the dozen or so offices that regularly land buildings over 300 m.