page_title: One World Trade Center
section_title: Design evolution
hierarchical_section_title: One World Trade Center / Current building (2013–present) / Architecture and design / Layout / Design evolution
context_page_description: One World Trade Center is the main building of the rebuilt World Trade Center complex in Lower Manhattan, New York City. One WTC is the tallest building in the United States, the tallest building in the Western Hemisphere, and the seventh-tallest in the world. The supertall structure has the same name as the North Tower of the original World Trade Center, which was 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 is David Childs, whose firm Skidmore, Owings & Merrill 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.
context_section_description: The original design went through significant changes after the Durst Organization joined the Port Authority of New York and New Jersey as the co-developer of the project in 2010.
  The 185-foot (56 m) tall base corners were originally designed to gently slope upward, and have prismatic glass. The corners were later squared. In addition, the base's walls are now covered in "hundreds of pairs of 13-foot vertical glass fins set against horizontal bands of eight-inch-wide stainless-steel slats."
  The spire was originally to be enclosed with a protective radome, described as a "sculptural sheath of interlocking fiberglass panels". However, the radome-enclosed spire was changed to a plain antenna. Douglas Durst, the chairman of the Durst Organization, stated that the design change would save $20 million. However, the tower's architect, Skidmore Owings & Merrill, strongly criticized the change. David Childs, the lead designer, said, "Eliminating this integral part of the building's design and leaving an exposed antenna and equipment is unfortunate ... We stand ready to work with the Port on an alternate design." After joining the project in 2010, the Durst Organization had suggested eliminating the radome to reduce costs, but the proposal was rejected by the Port Authority's then-executive director, Christopher O. Ward. Ward was replaced by Patrick Foye in September 2011. Foye changed the Port Authority's position, and the radome was removed from the plans. In 2012, Douglas Durst gave a statement regarding the final decision: "(the antenna) is going to be mounted on the building over the summer. There's no way to do anything at this point."
  The large triangular plaza on the west side of One World Trade Center, facing the Hudson River, was originally planned to have stainless steel steps descending to the street. However, the steps were changed to a terrace in the final design. The terrace can be accessed through a staircase on Vesey Street. The terrace is paved in granite, and has 12 sweetgum trees, in addition to a block-long planter/bench.
  Durst also removed a skylight from the plaza's plans; the skylight was designed to allow natural light to enter the below-ground observation deck lobby. The plaza is 5 ft 8 in (1.73 m) higher than the adjacent sidewalk.
  The Port Authority formally approved all these revisions, and the revisions were first reported by the New York Post. Patrick Foye, the executive director of the Port Authority, said that he thought that the changes were "few and minor" in a telephone interview.
  A contract negotiated between the Port Authority and the Durst Organization states that the Durst Organization will receive a $15 million fee and a percentage of "base building changes that result in net economic benefit to the project." The specifics of the signed contract give Durst 75 percent of the savings, up to $24 million, with further returns going down to 50 percent, 25 percent and 15 percent as the savings increase.
caption: Height comparison of major skyscrapers in New York City, with One World Trade Center shown at far left. The North Tower of WTC was 1,727 ft (526.3 m)