Claim: One World Trade Center has a steel structure.

One World Trade Center -LRB- also known as 1 World Trade Center , 1 WTC or Freedom Tower -RRB- is the main building of the rebuilt World Trade Center complex in Lower Manhattan , New York City . It is the tallest building in the Western Hemisphere , and the sixth-tallest in the world . The supertall structure has the same name as the North Tower of the original World Trade Center , which was completely destroyed in the terrorist attacks of September 11 , 2001 . The new skyscraper stands on the northwest corner of the 16 acre World Trade Center site , on the site of the original 6 World Trade Center . The building is bounded by West Street to the west , Vesey Street to the north , Fulton Street to the south , and Washington Street to the east .   The building 's architect was David Childs , whose firm Skidmore , Owings & Merrill -LRB- SOM -RRB- also designed the Burj Khalifa and the Willis Tower . The construction of below-ground utility relocations , footings , and foundations for the new building began on April 27 , 2006 . One World Trade Center became the tallest structure in New York City on April 30 , 2012 , when it surpassed the height of the Empire State Building . The tower 's steel structure was topped out on August 30 , 2012 . On May 10 , 2013 , the final component of the skyscraper 's spire was installed , making the building , including its spire , reach a total height of 1776 ft. Its height in feet is a deliberate reference to the year when the United States Declaration of Independence was signed . The building opened on November 3 , 2014 ; the One World Observatory opened on May 29 , 2015 .   On March 26 , 2009 , the Port Authority of New York and New Jersey -LRB- PANYNJ -RRB- confirmed that the building would be officially known by its legal name of `` One World Trade Center '' , rather than its colloquial name of `` Freedom Tower '' . The building is 104 standard floors high , but the tower has only 94 actual stories .   The new World Trade Center complex will eventually include five high-rise office buildings built along Greenwich Street , as well as the National September 11 Memorial & Museum , located just south of One World Trade Center where the original Twin Towers stood . The construction of the new building is part of an effort to memorialize and rebuild following the destruction of the original World Trade Center complex .