(3 of 5)
"There's a tremendously heightened sense of structural safety," says Anthony Vidler, dean of architecture at the Cooper Union in New York City. "Structures used to be designed like bridges, perfectly designed to meet the required need, such as getting a person from one side to another. Now we have a lot of redundancy in structures. If one thing fails, then another will hold, and if that fails, another will hold. It's akin to having five or six engines on a jet plane."
Though new American skyscrapers are not going to the same height as the supertalls being built in other nations, more complicated profiles are finally making their way into the U.S. skyline. Calatrava will be building a tower soon in New York City. His plan is for a structure that separates a dozen condos into discrete four-story modules--town houses in the sky. Each apartment is a $30 million, 10,000-sq.ft. package that's separately cantilevered from an 835-ft. central core, then further supported by exposed trusses that attach to steel piers running the full height of the building. The effect is a dynamic oscillation of forms, with alternating voids and volumes, something utterly unlike the inert slab that is the typical tower.
"I have an approach to the skyscraper as a sculptural element," says Calatrava, who likes to recall that when sculptor Constantin Brancusi set eyes on the New York skyline in the 1940s, he declared it looked just like his studio, a bristling collection of abstract statuary.
Sculptural would be a good way to describe Gehry's work too. If all goes as planned, ground will be broken next year in lower Manhattan for what will be by far the tallest building of his long career, a residential tower rising as much as 800 ft. (about 75 stories). Though the design is still incomplete, Gehry expects it will feature some vertical adaptation of his trademark curves and arabesques. Not too many years ago, those features would have given pause to the structural engineers assigned to make sure buildings stand up even when they rise along irregular lines. In the late '80s, Gehry proposed a design for a new Madison Square Garden in Manhattan--which was never built--with an office tower in the shape of a vertical fish. "The construction people said you couldn't do it," he recalls. "But since then it's become easy to do forms that have that much curvature and complexity. It's normal now."