The Council on Tall Buildings and Urban Habitat, based in Chigago, is generally recognized as the arbiter of height when it comes to the worldwide skyscraper competition. Although they set the categories and definitions by which buildings are judged against each other, "The answers aren't always clear in the race to the top, as shown this week by the news that One World Trade Center, the tower being erected at New York's Ground Zero, may not qualify as the Western Hemisphere's tallest building because plans to encase a rooftop antenna in fiberglass and steel have been scrapped."
Disputes have arisen over judgments on what constitutes a building's base and the difference between a spire and an antenna. "Antony Wood, CTBUH executive director, says it is up to users of the council's data to decide on record holders. 'We don't choose the tallest, the numbers do,' he says, adding, 'We have no axes to grind, or bias. Our only goals are to be accurate and consistent.'"