One World Trade Center is an edifice.
A building or edifice is a structure with a roof and walls standing more or less permanently in one place , such as a house or factory . One World Trade Center ( also known as 1 World Trade Center , 1 WTC or Freedom Tower ) is the main building of the rebuilt World Trade Center complex in Lower Manhattan , New York City . 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 building opened on November 3 , 2014 ; the One World Observatory opened on May 29 , 2015 .