“Ladies and gentlemen, are you ready to ruuumble!
        Welcome to the heavyweight bout for the title of the World's Tallest Building. Our contestants this evening include:
        • In this corner, the challenger, standing 1,776 feet (539 meters) tall and wearing the U.S. trunks, from New York City . . . the Freedom Tower!
        • And in this corner, the defending Tallest-Building champion, standing 1,483 feet (450 meters) tall and wearing the Malaysian trunks, from Kuala Lumpur, Petronas Towers!
        • And in this corner, standing - uh, well, we don't really know how tall he is, ladies and gentlemen - but, he is wearing the United Arab Emirates trunks, from Dubai City . . .
the Burj Dubai!”

        No one, of course, who experienced 9/11's searing horrors will ever forget that day.
        It's getting harder, though, to recall one popular prediction in 9/11's immediate aftermath: that the carnage sounded the death knell of skyscraper construction. Well, that was then . . .
        The skyscraper's future, it seems, has turned out quite differently. Suddenly, billion-dollar designs itching to grab the world's-tallest-building title are popping up everywhere. A boxing ring's four corners couldn't hold them all.
        But regardless of how high those structures actually stretch, this crown will nonetheless be claimed - continually - by multiple high-risers. In the edifice-complex wars, even defining the words tallest and building depends on who's doing the defining.

One new contender, the 1,776-foot-tall (539-meter), US$1.5-billion Freedom Tower, seems particularly likely to touch off a new wave of tallest-building redefinition. The project's design was unwrapped last month in New York.
        Understandably, Freedom Tower carries a hefty load of emotional and psychological freight, rising from the site of the terrorist-leveled World Trade Center (WTC). That symbolic status was much in evidence at the unveiling of its design.

Gov. George Pataki (right) discusses the new Freedom Tower at the announcement of the project's design.

        "Today we reclaim New York's skyline with a towering beacon to New York and our nation's resilience," said Gov. George E. Pataki (R).
        "The Freedom Tower will be a proud new symbol of our country's strength and a monument to our two lost icons," the governor added inside Federal Hall - not coincidentally, the same site that hosted the first meeting of the U.S. Congress and the writing of the Bill of Rights, as well as George Washington's inauguration.
        Empire State Development (www.empire.state.ny.us) Chairman Charles A. Gargano sounded a similarly weighty note.
        "The Freedom Tower will rise as a new icon to the resilience and strength of New York and America," said Gargano, also vice chair of the Port Authority of New York and New Jersey (www.panynj.gov.), which owns the WTC site and will occupy a third of the new building's office space. "It is a combination of art, engineering and design that is worthy of those we lost on Sept. 11."

Challenged champ: Malaysia's twin Petronas Towers (pictured) are currently the most widely recognized holder of the world's-tallest-building title.

        Even Freedom Tower's 1,776-foot (539-meter) height is symbolic, echoing the year of the United States' birth.

The phrase "the world's tallest building" popped up half a dozen times at the Federal Hall announcement. Freedom Tower is certainly much taller than the 110-story World Trade Center towers, which reached 1,350 feet (410 meters).
        And it may well be the world's tallest. Eventually. First, though, it has to be built, as well as occupied, most biggest-building arbiters agree.
        Once it is, though, Freedom Tower looks certain to rank as the world's tallest building - at least by some standards. The building would extend almost 300 feet (91 meters) above the current most widely recognized record-holder, Malaysia's Petronas Towers, standing 1,483 feet (450 meters) tall in Kuala Lumpur.
        Again, though, that persistent big-building question arises: How tall is tallest?
        The most widely acknowledged gold standard in answering that question is the Council on Tall Buildings and Urban Habitat (CTBUH at www.ctbuh.org), an international non-profit sponsored by architectural, engineering, planning and construction professionals. The CTBUH's mission includes "a major concern with the role of tall buildings in the urban environment and their impact thereon."
        At first glance, CTBUH's tallest-building yardstick seems clear. "The height of a building," the organization's guidelines say, "is measured from the sidewalk level of the main entrance to the structural top of the building."
        Or at least that's all they used to say. Seven years ago, though, the CTBUH settled a dispute by altering its standard. Now, it says, a building's "structural top . . . includes spires, but does not include television antennas, radio antennas or flag poles."
        Why the distinction? A building without its spire, the CTBUH explained, would look fundamentally different. But a building without its antennas or flag poles would look fundamentally the same.

And that's where the big-building debate gets contentious.
        To many Chicagoans' ire, the new "structural top" rule was created to break a tie between Petronas Towers and the Sears Tower, then the CTBUH's verticality champ. Rising to 1,758 feet (533 meters), Sears Tower in 1974 usurped New York's claim to the world's tallest building.
        That changed, though, with the CTBUH's new definition. The Petronas Towers are both topped by spires - which the CTBUH does count - 242 feet (73 meters) tall. But Sears Tower is topped by twin antennas - which the CTBUH doesn't count - 253 feet (77 meters) tall.
        The upshot: Sears Tower got "shorter," at least by CTBUH standards. Enough that Petronas was ruled 29 feet (nine meters) taller.
        Significantly, Freedom Tower also has an extension. The skyscraper's 2.6 million sq. ft. (234,000 sq. m.) of office space will actually top out at 1,500 feet (455 meters). Above that will be a 276-foot (84-meter), lattice-like structure containing windmills generating as much as 20 percent of the building's energy.
        But will that extension meet the CTBUH's "spires-count" standard? We don't know, and won't for some time. The CTBUH won't rule until after the building's projected 2009 completion and move-in.
        Freedom Tower's builders certainly seem to be shooting for spire status. That much was clear in a statement from The Lower Manhattan Development Corporation (LMDC at www.renewnyc.com), created in 9/11's aftermath to help plan and coordinate the area's rebuilding and revitalization. An artist will collaborate with architects and engineers to design a spire that "will place a sculpture in the sky . . . echoing the Statue of Liberty," the LMDC said.

Even with the CTBUH's imprimatur, though, Freedom Tower's tallest-building status could be fleeting. Numerous other contenders are waiting in the wings.
        None, however, are in the United States. Economic issues now limit most new U.S. skyscrapers to no more than 75 stories. Going higher devours profits, requiring too much bottom space, too little top space.
        In addition, Sept. 11 did dim skyscrapers' appeal in the U.S., a fact reflected in the Freedom Tower. Builders decided to top out office space at the 70th floor - 40 floors lower than the WTC. Going higher, they feared, would be a disincentive for building employees. (Freedom Tower also has myriad safety features, including extra strong fireproofing; biological and chemical filters in the air-supply system; extra-wide pressurized stairs; low-level emergency lighting; and direct exits to the street from tower stairs.)

The $1.8-billion Burj Dubai (pictured in an artist's rendering) is a wild card in the tallest-building battle. The builder says it will set a new standard; but it won't say how high that standard will be.

        Rather than economics, the non-U.S. tallest-building surge is being driven by a hunger for national and metropolitan prestige.
        One of the most ambitious non-America prestigious-seekers is Taipei 101. Standing 1,667 feet (511 meters) tall, the 101-story Taiwanese office and hotel tower is now under construction.
        When it's ready for occupancy in 2004, Taipei 101 would likely rank (however briefly) as the world's tallest building. And it could, conceivably, later be ruled even taller than Freedom Tower - at least in the seemingly unlikely event that the CTBUH rules that the New York building's lattice doesn't meet its guidelines.

Ah, but then there's the secrecy-shrouded skyscraper taking shape in Dubai City, the $1.8-billion Burj Dubai. Set to begin construction this year, the project is sure to be very big, containing homes, shops, offices and at least one hotel. Big enough for its builder to already claim that it's creating - you guessed it - the world's tallest building.

Some observers say the world's tallest-building title belongs to Toronto's CN Tower (pictured), which reaches 1,815 feet (551 meters). But other observers counter that the Canadian structure doesn't have enough occupied space, the association ruled, to be considered a building.

        How big, though, is unknown. The builder, state-controlled Emaar Properties (www.emarr.com), at first said that it intended to replicate the design for Grollo Tower, an Australian project that Melbourne planning authorities axed in 1999. That structure would've stood 1,850 feet (560 meters) tall.
        Then, though, Emaar Properties announced that it was doing a second design. The new design is finished, and it will create what Emaar Properties Chairman Mohamed Ali Alabbar calls "a new architectural benchmark."
        But the builder isn't saying how tall Burj Dubai's benchmark will be. That closemouthed strategy is aimed at keeping other title-seeking designers in the dark about the tallest-building target that they're trying to top.
        Other mine-is-bigger aspirants, though, aren't so reticent. One of the most prominent is Shanghai's World Financial Center, which recently resumed construction. Reaching 1,624 feet (492 meters), it will be the world's tallest, project backers assert.
        But wait a minute. Some big-building mavens argue that other existing structures are already the standard-setters. The Guinness Book of Records, for example, lists the CN Tower in Toronto as "the world's tallest building" at 1,815 feet (551 meters).
        In contrast, the CTBUH only calls CN Tower "the world's tallest free-standing structure." It doesn't have enough occupied space, the association ruled, to be considered a building.
        By whatever measuring stick, though, one thing seems clear: The debate over which building is biggest will definitely go on. And so will the race to build it.