July 2004

The World's Tallest Building (for Now)

A look at some of the building technologies that are enabling new skyscrapers to shatter height records.

By Patric Hadenius

Seizing the title of "world's tallest building"-be it Joseph Pulitzer's 20-story New York World newspaper building in lower Manhattan in 1890, the Empire State Building in 1931, or Kuala Lumpur, Malaysia's gargantuan Petronas Towers in 1998-has always been about pushing the limits of architecture and engineering. But three years after the attacks of September 11 demonstrated how vulnerable such buildings are to terrorists, a surprising new competition is under way. The latest skyline king is a vaguely pagoda-like tower in Taipei, Taiwan, called Taipei 101 (see "Inside Taipei 101," below). Slated for occupancy this fall, the 101-story structure stands 508 meters tall, more than half a football field higher than Petronas. On the horizon are even taller skyscrapers, including the Freedom Tower proposed for New York City's ground zero, and a business and residential colossus in Dubai, United Arab Emirates.

It's getting crowded at the top: several other massive skyscrapers, while not quite record-setters, have risen in Asian cities in the past decade, with another under construction in Shanghai, China. Indeed, eight of the world's ten tallest buildings are now in Asia. "Some Asian economies have grown more wealthy than before, and they now want to express their identities," says C. P. Wang, the architect of Taipei 101. "To me, a skyscraper is an easy way to do that." Indeed, proclaims Gail Fenske, an architecture professor at Roger Williams University in Bristol, RI, the world is in the midst of "a new skyscraper frenzy."

The height records themselves can't be credited to any breakthrough in technology. Apart from the introduction of higher-grade steel, composite materials, and new welding techniques, basic construction methods haven't changed much in the past couple of decades.

Still, technology is a key enabler of this "frenzy." For starters, the latest software helps architects and engineers work together, and with numerous models at the same time, says Dennis Poon, managing principal for Taipei 101 at Thornton-Tomasetti Engineers in New York City. "With these new tools, we can do quick 3-D analyses of several different types of designs," says Poon. "We just don't have to guess." It is these analyses that make it possible to quickly determine the best designs for building the world's tallest building in a typhoon- and earthquake-prone area like Taipei.

And basic structural improvements fortify these buildings. Unlike the World Trade Center, the new skyscrapers have hardened-concrete cores that house elevators and stairways, better protecting potential escapees from fire and blast damage. Sensing and communications technologies-among them structural sensors that monitor swaying and radio frequency identification systems to enhance security-improve the buildings' operation. The latest elevators include smart controls that do things like dampen vibrations and regulate air pressure. In all these areas, says Fenske, "the engineers are pushing the limits as far as they can."

The result will be a new set of skyscraper records-ones that other engineers will surely seek to surpass in the years and decades to come.

INSIDE TAIPEI 101

Taiwan's record-breaking 508-meter, 101-story skyscraper is built to withstand frequent typhoons and occasional earthquakes. It sports the world's fastest elevators and largest antisway system, seismic sensors, and Internet-linked security systems.

Taipei 101 is currently the tallest building in the world, in terms of highest structural element (a designation that excludes antennae). It eclipses the Petronas Twin Towers, which in 1998 claimed the title from Chicago's Sears Tower, ending its 24-year reign. Even taller buildings are proposed for New York City's ground zero and Dubai, United Arab Emirates. A tower nearly as tall as Taipei 101 is under construction in Shanghai, China.