One World Trade Center has reached a construction milestone by rising 260 ft above street level. Upon its completion in 2013, it will become the tallest office building in the United States reaching 104 stories.

Photo courtesy of the Port Authority of New York and New Jersey

Currently standing at the 26th floor level, the 1,776-ft-tall office building is being designed by David Childs of Chicago-based Skidmore, Owings and Merrill and developed by the Port Authority of New York and New Jersey and is scheduled to reach a height of 50 stories by the end of 2010. To date, more than 67,000 cubic yards of concrete have been poured for the tower, both above and below ground exceeding the amount of concrete used to build the entire Empire State Building.

One World Trade Center will incorporate design elements based on LEED Gold criteria with energy efficiency running 20% higher than city codes presently require. The tower will also feature office space ranging from 30,425 sq ft to 46,405 sq ft as well as a two-floor observation deck available to the general public, a skyline restaurant, and an antenna mast. The building’s 2.9 million sq ft total size includes 60 ft, or four floors, of below street-level space for water tanks, fuel storage, mechanical space, parking, retail and a lobby for observation deck elevators.

Tenants of One World Trade Center will be in close proximity to approximately 500,000 sq ft of shops, restaurants and services, as well as the WTC Transportation Hub, and the 9/11 Memorial and Memorial Museum, all of which are also being developed by the Port Authority of NY and NJ.

“One World Trade Center will set the international standard for state-of-the-art office space,” said Christopher O. Ward, executive director of the Port Authority of NY and NJ. “It incorporates the highest environmental and safety standards and provides a world-class tenant environment with a sprawling transportation network, high-end retail and related services that prospective tenants demand. We will continue to work aggressively every day to keep up the momentum.”