Ground Zero Supertower - One World trade Center - WORLD HISTORY VIDEOS

Ground Zero Supertower - One World trade Center - WORLD HISTORY VIDEOS

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One World Trade Center is the tallest building in Manhattan and the United States. It was expected a completion in 2013 but it was finished in 2014 it's Height 1776 feet gives it its nickname the Freedom Tower. The interlocking Triangle Design makes it a symbol of resilience and freedom, It was also the focus of the 2013 PBS documentary Ground Zero Supertower. One World Trade Center is the tallest Building in the Western Hemisphere and memorializes those who lost their lives in the terrorist attacks that took place on September 11, 2001.

Original building (1970–2001)


The construction of the World Trade Center, of which the Twin Towers (One and Two World Trade Center) were the centerpieces, was conceived as an urban renewal project and spearheaded by David Rockefeller. The project was intended to help revitalize Lower Manhattan.[19] The project was planned by the Port Authority of New York and New Jersey, which hired architect Minoru Yamasaki. Yamasaki came up with the idea of building twin towers. After extensive negotiations, the New Jersey and New York State governments, which supervise the Port Authority, consented to the construction of the World Trade Center at the Radio Row site, located in the lower-west area of Manhattan.[20] To satisfy the New Jersey government, the Port Authority agreed to buy the bankrupt Hudson & Manhattan Railroad (renamed to Port Authority Trans-Hudson), which transported commuters from New Jersey to Lower Manhattan.[21]

Image. Freedom Tower

The towers were designed as framed tube structures, giving tenants open floor plans, unobstructed by columns or walls.[22][23] This design was accomplished by using many closely spaced perimeter columns, providing much of the structure's strength, with the gravity load shared with the core columns. The elevator system, which made use of sky lobbies and a system of express and local elevators, allowed substantial floor space to be used for office purposes by making the structural core smaller. The design and construction of the towers involved many other innovative techniques, such as wind tunnel experiments and the slurry wall for digging the foundation.[24][25]

Construction of the North Tower (One World Trade Center) began in August 1966; extensive use of prefabricated components sped up the construction process. The first tenants moved into the North Tower in December 1970.[26][27] In the 1970s, four other low-level buildings were built as part of the World Trade Center complex.[28][29] A seventh building was built in the mid-1980s.


The first One World Trade Center under construction in 1971

Specifications and operations

After Seven World Trade Center was built in the 1980s, the World Trade Center complex had a total of seven buildings; however, the most notable ones were the main Twin Towers built in the 1970s—One World Trade Center was the North Tower, and Two World Trade Center was the South Tower.[32] Each tower was over 1,350 feet (410 m) high, and occupied about 1 acre (0.40 ha) of the total 16 acres (6.5 ha) of the site's land. During a press conference in 1973, Yamasaki was asked, "Why two 110-story buildings? Why not one 220-story building?" His response was, "I didn't want to lose the human scale."

The Record for world's tallest building was previously held to The Empire State Building, which had held the record for 40 years. The North Tower was 1,368 feet (417 m) tall, and in 1978, a telecommunications antenna was added to the top of the roof; by itself, the antenna was 360 feet (110 m) tall. With the 360-foot (110 m)-tall antenna, the highest point of the North Tower reached 1,728 ft (527 m).[34] However, the tower only held its record until May 1973, when Chicago's Sears Tower(now Willis Tower), which was 1,450 feet (440 m) tall at the rooftop, was completed.[35] At 110 floors, the World Trade Center towers had more floors than any other building at that time.[34] This number was not surpassed until the construction of the Burj Khalifa (163 floors), which opened in 2010.

Construction and later development

Main article:

One World Trade Center tower construction as of August 7, 2007

One World Trade Center construction as of April 3, 2012, three months before topping off

The symbolic cornerstone of One World Trade Center was laid in a ceremony on July 4, 2004. The stone had an inscription supposedly written by . However, construction was delayed until 2006 due to disputes over money, security, and design. The last major issues were resolved on April 26, 2006, when a deal was made between developer and the Port Authority of New York and New Jersey, so the cornerstone was temporarily removed from the site on June 23, 2006. Soon after, explosives were detonated at the construction site for two months to clear for the building's foundation, onto which 400 cubic yards (310 cubic meters) of concrete was poured by November 2007.

In a December 18, 2006, ceremony held in nearby , members of the public were invited to sign the first 30-foot (9.1 m) steel beam installed onto the building's base. It was welded onto the building's base on December 19, 2006. Foundation and steel installation began shortly afterward, so the tower's footings and foundation were nearly complete within a year.

In January 2008, two cranes were moved onto the site. Construction of the tower's concrete core, which began after the cranes arrived, reached street level by May 17. However, construction of the base was not finished until two years later, after which construction of the office floors began, and the first glass windows were subsequently installed; during 2010, floors were constructed at a rate of about one per week. An advanced "cocoon" scaffolding system was installed to protect workers from falling, and was the first such safety system installed on a steel structure in the city. The tower reached 52 floors and was over 600 feet (180 m) tall by December 2010. The tower's steel frame was halfway complete by then, but grew to 82 floors by the tenth anniversary of the September 11 attacks, at which time its concrete flooring had reached 72 floors and the glass cladding had reached 56 floors.

In 2009, the Port Authority changed the official name of the building from "Freedom Tower" to "One World Trade Center", stating that this name was the "easiest for people to identify with." The change came after board members of the Port Authority voted to sign a 21-year lease deal with Vantone Industrial Co., a Chinese real estate company, which would become the building's first commercial tenant to sign a lease. Vantone plans to create the China Center, a trade and cultural facility, covering 191,000 square feet on floors 64 through 69.

Detailed floor plans of the tower were posted on New York City's Department of Finance website in May 2011. This resulted in an uproar from the media and citizens of the surrounding area, who warned that the plans could potentially be used for a future terrorist attack.

While under construction, the tower was specially illuminated on several occasions. On the weekend of July 4, 2011, it was lit up with the colors of the to commemorate , and it was lit up with the same colors on September 11 to mark the 10th anniversary of the September 11 terrorist attacks. On October 27 of that same year, it was illuminated with pink in honor of . On December 11, the Port Authority illuminated the tower with multicolored lights to celebrate the . On February 24, 2012, the building was lit up with red in honor of , who became a on February 18. On June 14, 2012, it was illuminated with red, white, and blue to honor . In August, it was illuminated with red in honor of the Armed Forces. On September 8, 2012, it was once again illuminated with red, white, and blue to honor the 11th anniversary of the September 11 attacks. On June 24, 2013, the building was again illuminated with red, white, and blue to celebrate the . On November 12, 2013, three hundred red, white, and blue lights were lit up.

The tower's loading dock, however, was not due to be finished in time to move equipment into the completed building, so five temporary loading bays were added at a cost of millions of dollars. The temporary PATH station was not to be removed until its official replacement, the , was completed, blocking access to the planned loading area. By March 2012, One World Trade Center's steel structure had reached 93 floors, growing to 94 floors and 1,240 feet (380 m) by the end of the month. However, because the floor numberings were based on standard measurements, the 94th floor was numbered "floor 100", because the extra space was occupied by the high-ceilinged 91st floor, which was used for mechanical purposes.

The still-incomplete tower became New York City's tallest building by roof height in April 2012, passing the 1,250-foot (380 m) roof height of the . President visited the construction site two months later and wrote, on a steel beam that would be hoisted to the top of the tower, the sentence "We remember, we rebuild, we come back stronger!" That same month, with the tower's structure nearing completion, the owners of the building began a public marketing campaign for the building, seeking to attract visitors and tenants.

One World Trade Center's steel structure topped out at the nominal 104th floor, with a total height of 1,368 feet (417 m), in August 2012. The tower's spire was then shipped from Quebec to New York in November 2012, and the first section of the spire was hoisted to the top of the tower on December 12, 2012, and was installed on January 15, 2013. By March 2013, two sections of the spire had been installed. The spire's completion was scheduled for April 29, 2013, but bad weather delayed the delivery of the final pieces. On May 10, 2013, the final piece of the spire was lifted to the top of One World Trade Center, bringing the tower to its full height of 1,776 feet (541 m), and making it the at the time. In subsequent months, the exterior elevator shaft was removed; the podium glass, interior decorations, and other finishings were being installed; and installation of concrete flooring and steel fittings was completed.

A report in September 2013 revealed that, at the time of the report, the World Trade Center Association (WTCA) was negotiating with regard to the "World Trade Center" name, as the WTCA had purchased the rights to the name in 1986. The WTCA sought $500,000 worth of free office space in the tower in exchange for the use of "World Trade Center" in the tower's name and associated souvenirs.

On November 12, 2013, the Height Committee of the -based (CTBUH) made the controversial announcement that One World Trade Center was the at 1,776 feet (541 m), declaring that the mast on top of the building is a spire since it is a permanent part of the building's architecture. By the same reasoning, the building was also the tallest in the Western Hemisphere.

  • The original Twin Towers, c. 2000
  • One World Trade Center under construction behind the in June 2011.
  • One World Trade Center (to the left) and under construction, as seen from a helicopter on April 30, 2012.

Opening and post-opening

On November 1, 2014, moving trucks started moving items for the tower's first occupying tenant, magazine publisher , from its in to One World Trade Center. The New York Times noted that the area around the World Trade Center had transitioned from a financial area to one with technology firms, residences, and luxury shops, coincident with the building of the new tower.

The building opened on November 3, 2014, and Condé Nast employees moved into spaces spread among 24 floors. Condé Nast occupied floors 20 to 44, having completed its move in early 2015. It was expected that the company would attract new tenants to occupy the remaining 40% of unleased space in the tower, as Condé Nast had revitalized Times Square after moving there in 1999. Only about 170 of 3,400 total employees moved into the new tower on the first day. At the time, future tenants included Kids Creative, Legends Hospitality, the , , and .

Disabled suspended working platform used for maintenance activities on southern exposure

On November 12, 2014, the supporting cables of a suspended working platform slacked. The cables were manufactured by Tractel, and they were used to hold workers who performed maintenance on the building's exterior. At the time, the platform was holding a two-man, -affiliated team. The slack caused the platform to hang almost vertically near the 68th floor of the tower. The workers were rescued by over 100 , who used a to cut through the glass. After the incident, the workers suffered from a slight case of hypothermia, and were taken to the hospital.

Estimated cost and funding

An estimate in February 2007 placed the initial construction cost of One World Trade Center at about $3 billion, or $1,150 per square foot ($12,380 per square meter). However, the tower's total estimated construction cost had risen to $3.9 billion by April 2012, making it the most expensive building in the world at the time. The tower's construction was partly funded by approximately $1 billion of insurance money that Silverstein received for his losses in the September 11 attacks. The State of New York provided an additional $250 million, and the Port Authority agreed to give $1 billion, which would be obtained through the sale of . The Port Authority raised prices for bridge and tunnel tolls to raise funds, with a 56 percent toll increase scheduled between 2011 and 2015; however, the proceeds of these increases were not used to pay for the tower's construction.

Architecture and design

Preliminary site plans for the World Trade Center's reconstruction. In orange are the new buildings (One World Trade Center is the square at upper left), and in blue is the 9/11 Memorial and Museum.

Many of 's original concepts from the 2002 competition were discarded from the tower's final design. One World Trade Center's final design consisted of simple symmetries and a more traditional profile, intended to compare with selected elements of the contemporary New York skyline. The tower's central spire draws from previous buildings, such as the and the . It also visually resembles the original Twin Towers, rather than being an off-center spire similar to the . One World Trade Center is considered the first major building whose construction is based upon a three-dimensional .

The building occupies a 200-foot (61 m) square, with an area of 40,000 square feet (3,700 m2), nearly identical to the footprints of the original Twin Towers. The tower is built upon a 185-foot (56 m) tall windowless concrete base, designed to protect it from and other ground-level attacks. Originally, the base was to be covered in decorative glass, but a simpler glass-and-steel façade was adopted when the prisms proved unworkable. The current base cladding consists of angled glass fins protruding from stainless steel panels, similar to those on . lights behind the panels illuminate the base at night. Cable-net glass façades on all four sides of the building for the higher floors, designed by , will be consistent with the other buildings in the complex. The façades are 60 feet (18 m) high, and range in width from 30 feet (9.1 m) on the east and west sides, 50 feet (15 m) on the north side, and 70 feet (21 m) on the south side. The curtain wall was manufactured and assembled by Benson Industries in , using glass made in by Viracon.

From the 20th floor upwards, the square edges of the tower's cubic base are back, shaping the building into eight tall , or an elongated . Near its middle, the tower forms a perfect octagon, and then culminates in a glass , whose shape is a square oriented 45 degrees from the base. A 408-foot (124 m) sculpted mast containing the broadcasting antenna – designed in a collaboration between (SOM), artist (who invented the structure), lighting designers, and engineers – is secured by a system of cables, and rises from a circular support ring, which contains additional broadcasting and maintenance equipment. At night, an intense beam of light is projected horizontally from the spire and shines over 1,000 feet (300 m) above the tower.

of SOM, the architect of One World Trade Center, said the following regarding the tower's design:


Entrance to the tower

Just south of the new One World Trade Center is the , which is located where the original Twin Towers stood. Immediately to the east is and the new site. To the north is , and to the west is .

One World Trade Center as seen from the National September 11 Memorial

One World Trade Center's top floor is officially designated as floor 104, despite the fact that the tower only contains 94 actual stories. The building has 86 usable above-ground floors, of which 78 are intended for office purposes (approximately 2,600,000 square feet (240,000 m2)). The base consists of floors 1–19, including a 65-foot-high (20 m) public lobby, featuring the 90-foot mural by American artist . The office floors begin at floor 20, and go up to floor 63. There is a on floor 64; office floors resume on floor 65, and stop at floor 90. Floors 91–99 and 103–104 are .

Visitors looking toward from One World Observatory

The tower has a three-story observation deck, located on floors 100–102, in addition to existing broadcast and antenna facilities. Similar to the , visitors are separated from the tenants, having their own separate entrance next to the museum, descending down to a below-ground security screening area. On the observation deck, the actual viewing space is on the 100th floor, but there is a food court on the 101st floor and a space for events for the 102nd floor. To show visitors the city, and give them information and stories about New York, an interactive tool called City Pulse is used by Tour Ambassadors. The admission fee is $32 per person, but admission discounts are available for children and seniors, and the deck is free for 9/11 responders and families of 9/11 victims. When it opened, the deck was expected to have about 3.5 million visitors per year. Tickets went on sale starting on April 8. However, the probed the Port Authority about the firm to which it awarded a contract to operate the deck. It officially opened on May 28, 2015, one day ahead of schedule.

There are three eating venues at the top of the building: a café (called One Café), a bar and "small plates" grill (One Mix), and a fine dining restaurant (One Dining). Some have criticized the food prices; the need of a full observatory ticket purchase to enter; and their reputations compared to , the top-floor restaurant in the original One World Trade Center. The tenants have access to below-ground parking, storage, and shopping; access to , trains, and the is also provided at the , /, , and stations. The building allows direct access to West Street, Vesey Street, and Fulton Street at ground level. The building has an approximate underground footprint of 42,000 square feet (3,900 m2), of which 55,000 square feet (5,100 m2) is retail space. A plan to build a restaurant near the top of the tower, similar to the original One World Trade Center's , was abandoned as logistically impractical. The tower's window-washing tracks are located on a 16-square-foot area, which will be designated as floor 110 as a symbolic reference to the 110 floors of the original tower.

  • View of Manhattan from the observatory
  • Brooklyn Bridge as viewed from the observatory
  • West Street viewed from the observatory
  • as viewed from the observatory
Design evolution

The original design went through significant changes after the joined the Port Authority of New York and New Jersey as the co-developer of the project in 2010.

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)

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 , described as a "sculptural sheath of interlocking fiberglass panels". However, the radome-enclosed spire was changed to a plain antenna. , 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, . Ward was replaced by 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 , 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 . 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.

When viewed from street level in proximity to the tower, One World Trade Center appears to ascend to a pyramid point.

The top floor of One World Trade Center is 1,368 feet (417 m) above ground level, along with a 33 ft 4 in (10.16 m) ; this is identical to the roof height of the original One World Trade Center. The tower's spire brings it to a pinnacle height of 1,776 feet (541 m), a figure intended to symbolize the year 1776, when the was signed. When the spire is included in the building's height, as stated by the (CTBUH), One World Trade Center surpasses the height of (1,671-foot (509 m)), is the world's tallest all-office building, and the sixth-tallest skyscraper in the world, behind the , , , and .

One World Trade Center is the second-tallest , as the in exceeds One World Trade Center's pinnacle height by approximately 40 ft (12.2 m). The , with a planned height of 2,000 feet (610 m), was expected to exceed the height of One World Trade Center, but its construction was canceled due to financial difficulties in 2009.

After design changes for One World Trade Center's spire were revealed in May 2012, there were questions as to whether the 408-foot (124 m)-tall structure would still qualify as a spire, and thus be included in the building's height. Since the tower's spire is not enclosed in a radome as originally planned, it could be classified as a simple antenna, which is not included in a building's height, according to the CTBUH. Without the antenna, One World Trade Center would be 1,368 feet (417 m) tall, making it the , behind the and , both located in Chicago, and in New York. The building is currently the tallest in New York City with the antenna; however, without the antenna, it was surpassed in 2015 by , which topped out at 1,396 feet (426 m) high. One World Trade Center's developers have disputed the claim that the spire should be reclassified as an antenna following the redesign, with Port Authority spokesman Steve Coleman reiterating that "One World Trade Center will be the tallest building in the Western Hemisphere." In 2012, the CTBUH announced that it would wait to make its final decision as to whether or not the redesigned spire would count towards the building's height. On November 12, 2013, the CTBUH announced that One World Trade Center's spire would count as part of the building's recognized height, giving it a final height of 1,776 feet, and making it the tallest building in the Western Hemisphere.


Like other buildings in the new World Trade Center complex, One World Trade Center includes features. Much of the building's structure and interior is built from recycled materials, including boards and ceiling tiles; around 80 percent of the tower's waste products are recycled. Although the roof area of any tower is limited, the building implements a rainwater collection and recycling scheme for its cooling systems. The building's generate 4.8 megawatts (MW) of power, and its waste steam generates electricity. The selected to provide the tower's fuel cell system, which was one of the largest fuel cell installations in the world once completed. The tower also makes use of off-site and . The windows are made of an ultra-clear glass, which allows maximum sunlight to pass through; the interior lighting is equipped with dimmers that automatically dim the lights on sunny days, reducing energy costs. Like all of the new facilities at the World Trade Center site, One World Trade Center is , with limited oil or natural gas utilities on-site. One World Trade Center is expected to receive a (LEED) Gold Certification, making it one of the most environmentally sustainable skyscrapers in the world.

Security features

Along with the protection provided by the reinforced concrete base, a number of other safety features were included in the building's design, so that it would be prepared for a major accident or terrorist attack. Like , the building has 3-foot (91 cm) thick reinforced concrete walls in all stairwells, elevator shafts, risers, and sprinkler systems. There are also extra-wide, stairwells, along with a dedicated set of stairwells exclusively for the use of firefighters, and biological and chemical filters throughout the ventilation system. In comparison, the original Twin Towers used a purely steel central core to house utility functions, protected only by lightweight panels.

The building is no longer 25 feet (8 m) away from , as the Twin Towers were; at its closest point, West Street is 65 feet (20 m) away. The windows facing West Street are equipped with specially tempered blast-resistant plastic, which looks almost like the glass used in the other sides of the building. The Port Authority has stated: "Its structure is designed around a strong, steel moment frame consisting of beams and columns connected by a combination of welding and bolting. Paired with a concrete-core shear wall, the moment frame lends substantial rigidity and redundancy to the overall building structure while providing column-free interior spans for maximum flexibility."

In addition to safety design, new security measures will be implemented. All vehicles will be screened for materials and other potentially dangerous objects before they enter the site through the underground road. Four hundred will be placed in and around the site, with live camera feeds being continuously monitored by the NYPD. A computer system will use , designed to detect potential threats, such as unattended bags, and retrieve images based on descriptions of terrorists or other criminal suspects. New York City and Port Authority police will patrol the site.

Before the World Trade Center site was fully completed, the plaza was not completely opened to the public, as the original World Trade Center plaza was. The initial stage of the opening process began on Thursday, May 15, 2014, when the "Interim Operating Period" of the ended. During this period, all visitors were required to undergo airport style security screening, as part of the "Interim Operating Period", which was expected to end on December 31, 2013. However, screening did not fully end until the official dedication and opening of the museum on May 21, 2014, after which visitors were allowed to use the plaza without needing passes.


In March 2014, the tower was scaled by 16-year-old resident , who entered the site through a hole in a fence. He was subsequently arrested on trespassing charges. He allegedly dressed like a construction worker, sneaked in, and convinced an elevator operator to lift him to the tower's 88th floor, according to news sources. He then used stairways to get to the 104th floor, walked past a sleeping security guard, and climbed up a ladder to get to the antenna, where he took pictures for two hours. The elevator operator was reassigned, and the guard was fired. It was then revealed that officials had failed to install security cameras in the tower, which facilitated Casquejo's entry to the site. Casquejo was sentenced to 23 days of community service as a result.

Less than a week after the trespassing incident, four people—three male parachutists (one of whom was a construction worker at the site) and their lookout—were arrested for a they conducted on September 30, 2013. They had posted a video of the jump online. As a result of these incidents, the 's head of security at One World Trade Center, David Velazquez, resigned on March 28, 2014.


The social center of the previous One World Trade Center included a restaurant on the 107th floor, called , and The Greatest Bar on Earth; these were tourist attractions in their own right, and a gathering spot for people who worked in the towers. This restaurant also housed one of the most prestigious wine schools in the United States, called "Windows on the World Wine School", run by wine personality . Despite numerous assurances that these attractions would be rebuilt, the Port Authority scrapped plans to rebuild them, which has outraged some observers.

The fortified base of the tower has also been a source of controversy. Some critics, including of the , have said that it is alienating and dull, and reflects a sense of fear rather than freedom, leading them to dub the building "the Fear Tower". Nicolai Ouroussoff, the architecture critic for , calls the tower base a "grotesque attempt to disguise its underlying paranoia".

Owners and tenants

Seen at sunset; the is in the background

One World Trade Center is principally owned by the . Around 5 percent equity of the building was sold to the , a private real estate company, in exchange for an investment of at least $100 million. The Durst Organization assisted in supervising the building's construction, and manages the building for the Port Authority, having responsibility for leasing, property management, and tenant installations. By September 2012, around 55 percent of the building's floor space had been leased, but no new leases were signed for three years until May 2014; the amount of space leased had gone up to 62.8 percent by November 2014.

In 2006, the State of New York agreed to a 15-year 415,000 square feet (38,600 m2) lease, with an option to extend the lease's term and occupy up to 1,000,000 square feet (90,000 m2). The (GSA) initially agreed to a lease of around 645,000 square feet (59,900 m2), and New York State's Office of General Services (OGS) planned to occupy around 412,000 square feet (38,300 m2). However, the GSA ceded most of its floor space to the Port Authority in July 2011, and the OGS withdrew from the lease contract. In April 2008, the Port Authority announced that it was seeking a bidder to operate the 18,000 sq ft (1,700 m2) observation deck on the tower's 102nd floor; in 2013, Legends Hospitality Management agreed to operate the observatory in a 15-year, $875 million contract.

The building's first lease, a joint project between the Port Authority and Beijing-based Vantone Industrial, was announced on March 28, 2009. A 190,810 sq ft (17,727 m2) "China Center", combining business and cultural facilities, is planned between floors 64 and 69; it is intended to represent Chinese business and cultural links to the United States, and to serve American companies that wish to conduct business in China. Vantone Industrial's lease is for 20 years and 9 months. In April 2011, a new interior design for the China Center was unveiled, featuring a vertical "Folding Garden", based on a proposal by the Chinese artist Zhou Wei.

On August 3, 2010, signed a tentative agreement to move the headquarters and offices for its magazines into One World Trade Center, occupying up to 1,000,000 square feet (90,000 m2) of floor space. On May 17, 2011, Condé Nast reached a final agreement with the Port Authority, securing a 25-year lease with an estimated value of $2 billion. On May 25, 2011, Condé Nast finalized the lease contract, obtaining 1,008,012 square feet (93,647.4 m2) of office space between floors 20–41. The lease also includes 30,000 square feet (2,800 m2) of usable space in the podium and below grade floors, for mail, messenger services, and storage use. On January 17, 2012, it was reported that Condé Nast would be leasing an additional 133,000 square feet (10,000 m2) of space, occupying floors 42 through 44. Conde Nast moved in on November 3, 2014.

However, some leases failed. In January 2012, , a -based law firm, was to sign a 300,000 square feet (30,000 m2) lease contract, but after negotiations broke down, the deal was abruptly canceled in March.

In August 2014, it was announced Servcorp signed a 15-year lease for 34,775 square feet (3,230.7 m2), taking the entire 85th floor. Servcorp subsequently all of its space on the 85th floor as private offices, boardrooms and to numerous medium-sized businesses such as ThinkCode, D100 Radio, and Chérie L'Atelier des Fleurs.

Key figures


of , the leaseholder and developer of the complex, retains control of the surrounding buildings, while the Port Authority has full control of the tower itself. Silverstein signed a 99-year lease for the World Trade Center site in July 2001, and remains actively involved in most aspects of the site's redevelopment process.

Before construction of the new tower began, Silverstein was involved in an insurance dispute regarding the tower. The terms of the lease agreement signed in 2001, for which Silverstein paid $14 million, gave Silverstein, as leaseholder, the right and obligation to rebuild the structures if they were destroyed. After the September 11 attacks, there were a series of disputes between Silverstein and insurance companies concerning the that covered the original towers; this resulted in the construction of One World Trade Center being delayed. After a trial resulted, a verdict was given on April 29, 2004. The verdict was that ten of the insurers involved in the dispute were subject to the "one occurrence" interpretation, so their liability was limited to the face value of those policies. Three insurers were added to the second trial group. At that time, the jury was unable to reach a verdict on one insurer, , but it did so several days later on May 3, 2004, finding that this company was also subject to the "one occurrence" interpretation. Silverstein appealed the Swiss Reinsurance decision, but the appeal failed on October 19, 2006. The second trial resulted in a verdict on December 6, 2004. The jury determined that nine insurers were subject to the "two occurrences" interpretation, referring to the fact that two different planes had destroyed the towers during the September 11 attacks. They were therefore liable for a maximum of double the face value of those particular policies ($2.2 billion). The highest potential payout was $4.577 billion, for buildings 1, 2, 4, and 5.

In March 2007, Silverstein appeared at a rally of construction workers and public officials outside an insurance industry conference. He highlighted what he describes as the failures of insurers and to pay $800 million in claims related to the attacks. Insurers state that an agreement to split payments between Silverstein and the Port Authority is a cause for concern.

Key project coordinators

, one of Silverstein's favorite architects, joined the project after Silverstein urged him to do so. He developed a design proposal for One World Trade Center, initially collaborating with Daniel Libeskind. In May 2005, Childs revised the design to address security concerns. He is the architect of the tower, and is responsible for overseeing its day-to-day design and development.

Architect won the invitational competition to develop a plan for the new tower in 2002. He gave an initial proposal, which he called "", for the design of One World Trade Center. His design included aerial gardens, windmills, and off-center spire. Libeskind later denied a request to place the tower in a more rentable location next to the PATH station. He instead placed it another block west, as it would then line up with, and resemble, the . Most of Libeskind's original designs were later scrapped, and other architects were chosen to design the other WTC buildings. However, one element of Libeskind's initial plan was included in the final design – the tower's symbolic height of 1,776 feet (541 m).

Daniel R. Tishman – along with his father , builder of the original World Trade Center – led the construction team from , the selected builder for One World Trade Center.

and Jody Durst, the co-presidents of the , a real estate development company, won the right to invest at least $100 million in the project on July 7, 2010.

In August 2010, Condé Nast, a long-time Durst tenant, confirmed a tentative deal to move into One World Trade Center, and finalized the deal on May 26, 2011. The contract negotiated between the Port Authority and the Durst Organization specifies 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 savings up to $24 million, stepping down to 50, 25, and 15 percent as savings increase. Since Durst joined the project, significant changes have been made to the building, including the 185 foot base of the tower, the spire, and the plaza to the west of the building, facing the Hudson River. The Port Authority has approved all the revisions.

Port Authority construction workers

A WoodSearch Films short-subject documentary entitled How does it feel to work on One World Trade Center? was uploaded to on August 31, 2010. It depicted construction workers who were satisfied with the working conditions at the construction site. However, further analysis of the work site showed that dozens of construction-related injuries had occurred at the site during the construction of One World Trade Center, including 34 not reported to the . Workers also left -related at the site, which are supposed to symbolize rebirth and resilience.