<P> The building 's architect was David Childs , whose firm Skidmore , Owings & Merrill ( SOM ) 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 1,776 feet ( 541 m ) . 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 . </P>
<P> The building 's architect was David Childs , whose firm Skidmore , Owings & Merrill ( SOM ) 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 1,776 feet ( 541 m ) . 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 . </P>
who is the architect of one world trade center
who is the architect of one world trade center
David Childs
David Childs