One World Trade Center

One World Trade Center (1 World Trade Center), more simply known as 1 WTC and formerly known (and still coentially known) as the Freedom Tower, is the lead building of the new World Trade Center complex in Lower Manhattan in New York City. The tower will be located in the northwest corner of the World Trade Center site, and will occupy the location where the original 8-story 6 World Trade Center once stood. The north side of the tower runs between the intersection of Vesey and West streets on the northwest and the intersection of Vesey and Washington streets on the northeast, with the site of the original North Tower/1 WTC offset to the southeast. Construction on below-ground utility relocations, footings, and foundations for the building began on April 27, 2006. On March 30, 2009, the Port Authority confirmed that the building will be known by its legal name of 'One World Trade Center', rather than the colloquial name 'Freedom Tower'. Upon completion, One World Trade Center will be the tallest building in the United States, standing at a symbolic height of 1776 ft, and among the tallest buildings in the world. It will be completed by January of 2013.

Along with One World Trade Center, the new World Trade Center site will feature three other high-rise office buildings along Greenwich Street and the National September 11 Memorial & Museum. The construction is part of an effort to memorialize and rebuild after the original World Trade Center complex was destroyed during the terrorist attacks of September 11, 2001. Upon completion, One World Trade Center will become the tallest all-office building in the world.

History
Following the destruction of the World Trade Center of September 11, 2001, there was much debate regarding the future of the World Trade Center site. Proposals began almost immediately, and by 2003, the Lower Manhattan Development Corporation organized a competition to determine how to use the land. Public rejection of the first round of designs, the "Preliminary Design Concepts", led to a second, more open competition in December 2002, the "Innovative Design Study", in which a design by Daniel Libeskind was selected. This design went through many revisions, largely because of disagreements with developer Larry Silverstein, who held the lease to the World Trade Center site on September 11, 2001.

A final design for the "Freedom Tower" was formally unveiled on June 28, 2005. To satisfy security issues raised by the New York City Police Department, a 187 ft concrete base was added in April of that year. The final design included plans to clad the base in glass prisms to address criticism that the base looked like a "concrete bunker" (though these proved unworkable and a simpler facing is planned). Contrasting with Libeskind's plan, the final design tapers octagonally as it rises. Its designers stated that the tower will be a "monolithic glass structure reflecting the sky and topped by a sculpted antenna." Commenting on a completion date, Larry Silverstein stated in 2006: "By 2012 we should have a completely rebuilt World Trade Center more magnificent, more spectacular than it ever was." On April 26, 2006, the Port Authority of New York and New Jersey approved a conceptual framework that enabled foundation construction to begin, and a formal agreement was drafted on the following day, the 75th anniversary of the opening of the Empire State Building. Construction began in May with a formal ceremony that took place when the construction team arrived. The building's topping out has been pushed back to at least late 2011, and it is projected to be ready for occupancy in 2013.

In 2009, the Port Authority changed the name of the building from "Freedom Tower" to "One World Trade Center", stating that this name is the "easiest for people to identify with".

Architecture
Many remaining vestiges of the concepts drawn from the 2002 competition have since been discarded. One World Trade Center will now consist of simple symmetries and a more traditional design intended to bear comparison with selected elements of the existing New York skyline. There will now be a central spire drawing from precedents such as the Empire State Building and the Chrysler Building (and also visually reminiscent of Tower 1 of the old World Trade Center) rather than an off-center spire intended to echo the Statue of Liberty.

According to David Childs of Skidmore, Owings and Merrill, the project architect of the new 1 World Trade Center, the tower:

Design
One World Trade Center's design includes 2600000 sqft of office space, as well as an observation deck, parking and broadcast and antenna facilities, all supported by both above and below-ground mechanical infrastructure for the building and its adjacent public spaces. Below-ground tenant parking and storage, shopping and access to the PATH and subway trains and the World Financial Center are also provided.

A 65 ft high public lobby, topped by a series of mechanical floors, form a 200 ft-per-side visual cubic base to the tower. The next 69 floors, providing tenant office space, rise above the base to an elevation of 1150 ft. Mechanical and observation floors culminate in a rooftop observation deck at 1362 ft with a glass parapet extending to 1368 ft — the heights of the original Twin Towers. A shrouded antenna structure supported by cables, engineered by Schlaich Bergermann & Partner, rises to a total height of 1776 ft, which is a tribute to the year the United States Declaration of Independence was signed. A plan to build a restaurant near the top of the tower was abandoned as logistically too difficult.

The 200 ft sides at the square footprint of the base are almost as wide as the 208 ft square of the original Twin Towers. The 185 ft window-less concrete base was added to the design in 2005 to increase strength to withstand a truck bomb, and the building was moved further from the West Side Highway. The design was criticized as uninviting and fortress-like. To address this, the base was to be clad in more than 2,000 pieces of prismatic glass designed to draw upon the themes of motion and light. This proved unworkable, however, and a simpler glass facade is planned for the base. Cable-net glass facades on all four sides of the building for the higher floors, designed by Schlaich Bergermann, will be consistent with the other buildings in the complex. They measure 60 ft high and range in width from 30 ft on the east and west sides (for access to the observation deck) to 50 ft on the north side and 70 ft on the south for primary tenant access. The curtain wall is being manufactured and assembled in Portland, Oregon by Benson Industries using glass made in Minnesota by Viracon.

As the tower rises from this cubic base, its square edges are chamfered back, transforming the square into eight tall isosceles triangles in elevation, or an elongated square antiprism. At its middle, the tower forms a perfect octagon in plan and then culminates in a glass parapet (elevation 1362 ft and 1368 ft) whose plan is a square, rotated 45 degrees from the base. A mast containing the antenna for television broadcasters – designed by a collaboration among SOM, artist Kenneth Snelson (who invented the tensegrity structure), lighting designers and engineers – is secured by a system of cables, and rises from a circular support ring, similar to the Statue of Liberty's torch, to a height of 1776 ft. Above the mast will be an intense beam of light that will be lit at night and will likely be visible over 1000 ft into the air above the tower.

New safety features will include 3 ft thick reinforced concrete walls for all stairwells, elevator shafts, risers, and sprinkler systems; extremely wide "emergency stairs"; a dedicated set of stairwells exclusively for the use of firefighters; and biological and chemical filters throughout its ventilation system. The building will no longer be 25 ft away from West Street, as the Twin Towers were. At its closest point, West Street will be 65 ft away. The windows on the side of the building facing in this direction will be equipped with specially tempered blast-resistant plastic, which will look nearly the same as the glass used in the other sides of the building. The seventy elevators and 9 escalators for 1 World Trade Center will be provided by ThyssenKrupp, with steel counterweights supplied by Concord Steel. The Port Authority has stated: "Its structure is designed around a strong, redundant 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."

1 World Trade Center will be green in several ways. Although the roof area of any tower is comparatively limited, the building will implement a rainwater collection and recycling scheme for its cooling systems. The building's fuel cell will generate 4.8 million watts (MW), and waste steam will help generate electricity. One World Trade Center is expected to receive a Gold Certification by Leadership in Energy and Environmental Design. Like all of the new facilities at the World Trade Center site, One World Trade Center will be heated by steam, with limited oil or natural gas utilities located on site.

Close to the building are the below-ground memorials featuring two glass reflecting pools. These pools are approximately 30 ft below the surface, and are located on the exact locations of the former Twin Towers. The pools are intended to fill out the "footprint" of the towers, each being equal to the exact perimeter of the North and South Tower. Trees surround the area containing the pools, and the area is intended to be a contemplative and quiet area separated from the city. The names of the nearly 3,000 victims of the attacks on September 11, 2001 and 1993 World Trade Center Bombing will be inscribed in bronze and placed around each pool. Under the pools, there will be a museum of the World Trade Center attacks, called the National September 11 Memorial & Museum. The memorial is scheduled to be completed by September 11, 2011, the tenth anniversary of the attacks on the World Trade Center.

Height
The roof (including a 33ft 4in parapet) of the top floor of One World Trade Center will be 1368 ft, the same as the original One World Trade Center. With its spire height (the criteria of two categories of the Council on Tall Buildings and Urban Habitat), One World Trade Center will stand at 1776 ft, a figure symbolic of the year of the United States Declaration of Independence.

With a structural height of 1776 ft, One World Trade Center will surpass the 1671 ft height of Taipei 101 to become the world's tallest all-office building and the tallest building in the Americas, surpassing the Willis Tower (formerly known as the Sears Tower) in Chicago. However, its roof height will still be 83 ft shorter than the Willis Tower. When completed, One World Trade Center will be the third tallest building in the world, behind the Burj Khalifa and the Mecca Royal Hotel Clock Tower.

The Chicago Spire (with a planned height of 2000 ft) was expected to exceed the height of One World Trade Center, but its construction was cancelled in 2009 due to financial difficulties. A new 2000ft+ tower is currently planned in Chicago's Old Post Office Redevelopment project.

The World Trade Center's South Tower had an outdoor rooftop observation deck at 1380 ft and another indoor observation deck at 1310 ft. One World Trade Center's indoor observation deck will be at a height of approx 1313 ft.

Space allotment and security
One World Trade Center will have a top floor denoted as 82. The first office floor of the building atop the 200 ft square base will be designated as Floor 20, and the building will have 74 usable above-ground floors. Sixty-nine floors will be designated as office floors. Additionally, roughly 55000 sqft of retail space will exist below-grade, part of an overall 500000 sqft of retail space to be spread throughout the site both in the below-grade concourses and on the lower floors of Towers 2, 3, and 4.

In addition to the protection offered by the reinforced, window-less base, a number of other design and security features are planned for the building. For example, all vehicles will be screened before they enter the site via the underground roadway, including for radioactive materials. Visitors to the September 11 memorial will undergo an airport-style screening. 400 closed-circuit surveillance cameras will be placed in and around the trade center site. Live feeds will be monitored around the clock by the NYPD, and a computer system will use "video analytic" computer software designed to detect potential threats like unattended bags and retrieve images based on descriptions of terror or other criminal suspects. New York City and Port Authority police will patrol the site.

Owners and Tenants
The building is owned principally by the Port Authority of New York and New Jersey. Around 5% equity of the building was sold to the Durst Organization in exchange for an investment of at least US$100 million. Durst Organization assists in supervising the building construction, manages the building for the Port Authority and is responsible for leasing, property management and tenant installations.

The State of New York has agreed to a 15-year lease of 415000 sqft of space inside 1 WTC, with an option to extend the term of the lease and occupy up to 1000000 sqft. The General Services Administration (GSA) has agreed to lease approximately 645000 sqft of space, New York State's Office of General Services (OGS) plans to lease approximately 412000 sqft of space. In April 2008, the Port Authority announced that it was seeking a bidder to operate an 18000 sqft observation deck on the tower's 102nd floor.

The building's first lease was announced on March 28, 2009, as a joint project between the Port Authority of New York and New Jersey and Vantone Industrial Co. based in Beijing, that will create a 190810 sqft "China Center", a business and cultural facility located between floors 64 and 69, that is said will represent business and cultural communities in China and serve as a hub for Chinese firms developing United States operations, as well as for US companies that wish to conduct business in China. The lease is for 20 years and 9 months.

On August 3, 2010, Condé Nast signed a tentative agreement to move the headquarters and offices of its 18 magazines into up to 1000000 sqft of the building. Nine months later, on May 17, 2011, Condé Nast reached a final agreement with the Port Authority to lease the space, a deal estimated to be valued at $2 billion over 25 years.

On May 25, 2011, Conde Nast finalized its lease agreement with the Port Authority. The lease is for 1,008,012 sqft of office space, occupying floors 20-41. The lease also covers an additional 30,000 sqft of usable space in the podium and below grade floors for mail, messenger services, and storage use.

2004–2007
The symbolic cornerstone of One World Trade Center was laid down in a ceremony on July 4, 2004, but further construction of the tower was stalled until 2006. The cornerstone was temporarily removed from the site on June 23, 2006. The project was delayed due to acrimonious disputes over money, security and design but the last major issues were resolved on April 26, 2006 with a deal between developer Larry Silverstein and the Port Authority of New York and New Jersey. For two months during the summer of 2006, explosives were detonated at the World Trade Center construction site, testing the use of charges to clear bedrock for the building's foundation.

On November 18, 2006, 400 cuyd of concrete were poured onto the foundation of the One World Trade Center, carried by as many as 40 trucks. On December 17, 2006, a ceremony was held in Battery Park City, with the public invited to sign a 30 ft steel beam. This beam, the first to be installed, was welded on to the building's base on December 19, 2006.

On January 9, 2007, a second set of beams was welded to the top of the first set. February 2007 estimates put the cost for construction of 1 WTC at $3 billion, or $1,150 per square foot ($12,380 per square meter). Approximately $1 billion of insurance money recouped by Silverstein in connection with the September 11 attacks is being used for construction of the new One World Trade Center. The State of New York is expected to provide $250 million toward construction costs, and the Port Authority agreed to finance another $1 billion through bonds. In 2007, Tishman Construction Corporation of New York completed a row of steel columns at the perimeter of the construction site. Two tower crane bases were erected, each base containing a functioning luffing-jib tower crane. By the end of 2007, the tower’s footings and foundations were nearly complete.

2008–2009
In January 2008, two construction cranes were moved into the construction site. The tower's concrete core began rising in the first months of 2008. By February 22, 2008, 9,400 of the nearly 50000 ST of steel necessary had been ordered. By March 13, 2008, the steel for the tower had reached 70 ft high, 10 ft below street level. From late March through early April, a 40 ft tall mockup of a section of the tower's wall with twenty-four windows was tested by Construction Consulting Laboratory West in Ontario, California. Testing also took place on another full-scale mockup south of Albuquerque, New Mexico. Both mockups passed the tests. In mid-April, a batch of concrete had to be replaced after it failed a stress test.

On May 17, 2008, the tower's steel breached street level when new sections were bolted to two of the twenty-four jumbo steel columns marking the building's footprint. The new column sections brought the height of the structure up to 15 ft above street level. In June, the chamfered steel skeleton of the tower's concrete base had begun to take shape. By the end of the month, the concrete had been poured for the floor of the tower's basement level B3. In his June 30, 2008 World Trade Center Rebuilding Assessment to New York Governor David Paterson, Port Authority executive director Chris Ward noted that roughly 90 percent of the construction contracts had been bid.

By August, 1 WTC had reached 25 ft above street level. During its September 16 meeting, the Port Authority board approved contracts for security and building management systems, and 95% of the contracts needed to complete the tower had been signed. On October 10, Collavino Construction poured an additional 520 cuyd of concrete for the tower's concrete core, raising it to just above street level.

By February 11, 2009, the tower was 105 ft above street level. On July 2, 2009, over 1200 cuyd of concrete were poured to form parts of the street-level plaza. On August 13, the builders of 1 WTC set a 70 ST piece of steel into place—the largest column installed yet at the building. Each steel column—made at a factory in Luxembourg—was about 60 ft long. The columns at the bottom of the tower's foundation were about 35 ft long.

By November 1, 2009, the twenty-four perimeter columns of 1 WTC were all erected, and construction of the second floor (the first floor above ground level) was nearly complete. In addition, The Port Authority of New York and New Jersey reported in their 2009 Q3 Annual Report that steel erection should commence by January 2010, and that the typical floor construction could begin.

2010–2011
Steel and concrete installation continued in 2010, where two cranes were on site. The fifth floor was finished on January 16. In February, construction began on the sixth floor, the last floor of 1 WTC's base, and the Port Authority announced that the tower's steel superstructure had reached 200 ft above street level. By the end of March 2010, steel beams began to be erected for the second office floor. In April, the 45-degree octagon was installed, the building's steel frame had reached 26 floors, with concrete completed on the base structure in the latter part of the month.

In May 2010, the Port Authority stated they were building close to one floor per week, and it was projected that 1 WTC would reach 55 stories by the end of 2010. A cocoon system for the tower was also installed, marking the first time that such a safety system had been installed on a steel structure in the city.

On July 13, 2010, workers found remains of an 18th century sailing ship at the World Trade Center site while excavating for the underground vehicle security center for the tower.

By October 2010, the tower's steel superstructure had reached 44 stories, and by November, stainless steel and glass facade panels were being prepared for later installation, with the panels scheduled to be assembled between the 20th and 24th floors. Steven Coleman, spokesman for the Port Authority, stated, "Once they get rolling, they'll be able to install glass panels at a rate of one floor per week." By mid-November, the tower's steel had reached 48 stories.

The Port Authority announced on December 16, 2010 that the tower had reached the 52nd floor, and had risen to over 600 ft, marking the halfway point for the tower's steel frame. By February 2011, the tower had reached the 56th floor, 667 ft above grade, with glass panels reaching the 27th floor. On May 12, 2011, plans were cancelled to install prismatic glass on the tower's base due to technical problems. By June 2011, the tower had reached the 70th floor, with glass paneling and concrete flooring reaching the 45th and 63rd floors, respectively. By late-August, the tower had reached the 80th floor, with glass paneling and concrete flooring reaching the 53rd and 72nd floors, respectively.

Estimated completion and cost
One WTC was originally expected to be completed and opened by 2011, but an October 2008 report by the PANYNJ pushed back the estimated completion of the tower to the second  quarter of 2012, with the total estimated budget growing slightly from the 2007 estimate to $3.1 billion. As of July 2011, the building remains scheduled to be completed by the end of 2013, according to the Port Authority.

Controversies
The design of 1 WTC generated controversy due to the limited number of floors in the previous design (82) that were designated for office space and other amenities. The overall office space of the entire rebuilt World Trade Center will be reduced by more than 3000000 sqft as compared with the original complex. The floor limit was imposed by Silverstein, who expressed concern that higher floors would be a liability in another major accident or terrorist attack. In a subsequent design, the highest space that could be occupied became comparable to the original World Trade Center.

An unofficial movement to rebuild the lost towers instead of building a single tower, called The Twin Towers Alliance, collected more than seven thousand signatures supporting the rebuilding of the Twin Towers. Developer Donald Trump proposed a twin building design called World Trade Center Phoenix (Twin Towers II). The twin design would look similar to the original twin towers, but the buildings would be considerably taller with improved safety measures and would feature much larger windows.

Former New York Governor George Pataki faced accusations of cronyism for supposedly using his influence to get the winning architect's bid picked as a personal favor for a close friend.

The base of the tower (fortified because of security concerns) has also been a source of controversy. A number of critics (notably Deroy Murdock of the National Review) have suggested that it is alienating and dull, and reflects a sense of fear rather than freedom, leading them to dub the project "the Fear Tower".

In May 2011, detailed floor plans of the tower were displayed on New York City's Department of Finance website resulting in an uproar from the media and citizens of the surrounding area who questioned the potential use of the plans for a future terrorist attack. New York Police Department Chief Ray Kelly described One World Trade Center as "the nation's number one terrorist target".

Larry Silverstein
Larry Silverstein of Silverstein Properties, the leaseholder and developer of the complex, will retain 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. Silverstein has pledged to support the reconstruction and remains actively involved in most aspects of the redevelopment process.



David Childs
David Childs, one of Silverstein's favorite architects, initially joined the project at the urging of Silverstein and developed a proposal for 1 WTC in collaboration with Daniel Libeskind. The design was revised in May 2005 to address security concerns. He is the project architect of the tower, and is responsible for overseeing the day-to-day design development from rough inception to final completion.

Daniel Libeskind
Architect Daniel Libeskind won the invitational competition to develop a master plan for the World Trade Center's redevelopment in 2002. He included an initial proposal for the design of 1 WTC, a building with aerial gardens and windmills with an off-center spire. It was also Libeskind who denied a request to place the tower in a more rentable location next to the PATH station and instead placed it a block west because in profile it would line up with and resemble the Statue of Liberty. Although these designs have since been changed, his contributions continue to shape the design and development at the World Trade Center site.

Dan Tishman
Dan Tishman, along with his father John Tishman, builder of the original World Trade Center, is leading the construction management effort for Tishman Realty & Construction, the selected builder for 1 WTC.

Douglas and Jody Durst
The co-presidents of the real estate development company The Durst Organization won the right to invest at least $100 million (but could reach as high as $300 million) in the project on July 7, 2010. They are a family-owned company that specializes in the development, managing, leasing, and operations of sustainable commercial construction space. Conde Nast, a long-time Durst tenant, also confirmed a tentative deal to move into 1 World Trade Center in August 2010, and finalized the deal on May 26, 2011.

Port Authority Construction Workers
A WoodSearch Films short-subject documentary was uploaded to YouTube on August 31, 2010, titled "How does it feel to work on One World Trade Center?". Nearly all of the construction workers interviewed spoke with praise of the unity and expert work ethic of the new World Trade Center's construction team. Others spoke of the importance they believed the construction of the tower had to the people of the United States. A deputy foreman, George Collins, said, "All the men are working in conjunction to put this building up. They all know how important this is to the country – and to show the world what us Americans can do – and get this done, union and proud." Another deputy foreman, Scott Williams, commented, "[The] camaraderie of the crew is very good."

August 3, 2011 marked the last day concrete workers didn’t show up for work at two World Trade Center sites as a standoff between union officials and management. The job action slowed the pace of construction at the World Trade Center’s 800,000 sqft transit hub and at One World Trade Center, but it returned to normal not long afterwards.