One World Trade Center Officially Tallest US Building

The Council on Tall Buildings and Urban Habitat announced Tuesday that One World Trade Center is now the tallest building in the United States, at 1,776 feet tall. Previously the tallest building honor went to the Willis tower in Chicago, IL, which stands 1,451 feet tall. The debated issue was whether or not the mast atop the new WTC building should be counted toward the architectural height. The council decided that since the 408 foot spire is a permanent architectural fixture, and not used for technical purposes, its length would be added to the total height of the building, therefore making it taller than the Willis Tower.

Willis Tower also has antennas atop its building, but their lengths are not added to the measured height. The reason being is they can be removed and changed, and they are not permanent parts of the building. If both buildings were measured from strictly the ground to the the tallest story, the Willis tower would beat out One WTC 1,354 ft to 1,268 ft.

Compared to the tallest buildings in the world, One WTC falls in at third behind the Burj Kahlifa (2,717 ft) and Makkah Royal Clock Tower Hotel (1,972 ft). 

Sources: CrainsNewYork, TheVerge