Chicago - The new World Trade Center tower in New York knocked Chicago's Willis Tower off its pedestal as the tallest building in the U.S. when an international panel of architects announced Tuesday that the needle atop the New York skyscraper can be counted when measuring the structure's height.The Height Committee of the Council on Tall Buildings and Urban Habitat said the needle is not an antenna but a spire, and thus is a permanent part of the building.The World Trade Center's needle, measuring 124 meters tall, was more than enough to knock down the Chicago building formerly known as the Sears Tower to second place, in a decision made by a Chicago-based panel."The committee was well aware of the gravity of the situation," Antony Wood, the council's executive director, said during a news conference.With the needle, 1 World Trade Center is a 1 776 feet (541m) tall, a height meant symbolize America's founding year. Without it, the building would have been only 1 368 feet (417 meters) tall - well short of the 1 451-foot (442-meter) Willis Tower.At stake was more than just bragging rights in two cities that feast on superlatives and the tourist dollars that might follow: 1 World Trade Center stands as a monument to those killed in the Sept. 11, 2001 attacks.The building's 417 meter height without the needle also holds symbolism; it is the height of the original World Trade Center.The 30 Height Committee members are industry professionals from all over the world and is widely recognized as the final arbiter of official building heights around the world. They conferred behind closed doors last week in Chicago, where the world's first skyscraper appeared in 1884.The new World Trade Center tower remains under construction and is expected to open next year.The designers originally had intended to enclose the mast's communications gear in decorative cladding made of fiberglass and steel. But the developer removed that exterior shell from the design, saying it would be impossible to properly maintain or repair. Without it, the question was whether the mast was now primarily just a broadcast antenna.Under the council's current criteria, spires that are an integral part of a building's aesthetic design count. Broadcast antennas that can be added and removed do not.