“The tower succeeds in realizing both its functional and symbolic purposes, employing a formal play in simple prismatic geometry that builds upon New York’s long skyscraper tradition.”
Mun Summ Wong, Jury Chair, WOHA Architects
Height: 541 m 1,776 ft
Stories: 94
Area: 325,279 sq m 3,501,274 sq ft
Primary Function: Office
Owner: 1 World Trade Center LLC
Developers: Port Authority of New York and New Jersey; The Durst Organization
Architect: Skidmore, Owings Merrill LLP design
Structural Engineers: WSP Group design; Schlaich Bergermann und Partner design; Leslie E. Robertson Associates peer review
MEP Engineer: Jaros, Baum Bolles design
Project Manager: STV
Main Contractor: Tishman Construction
Other Consultants: AECOM cost; Arnold Porter LLP environmental; Benson Industries faade; Brandston Partnership, Inc. lighting; Cerami Associates acoustics; Claude Engle lighting; Code Consultants, Inc. code; Ducibella Venter Santore security; Jaros, Baum Bolles vertical transportation; Lerch Bates faade maintenance; Mathews Nielsen Landscape Architects landscape; Mueser Rutledge Consulting Engineers geotechnical; Pentagram way finding; Permasteelisa Group faade; Peter Walker Landscape Architects landscape; Philip Habib Associates civil, traffic; RWDI wind; The Hettema Group observatory; Viridian Energy Environmental, LLC sustainability
Rising from the northwest corner of the 6.5-hectares World Trade Center site, One World Trade Center recaptures the New York skyline, reasserts downtown Manhattan’s pre-eminence as a business center, and establishes a new civic icon for the United States. It is a memorable architectural landmark for the city and the nation, and will connect seamlessly to its surroundings with entrances on all four elevations and linkages to an extensive underground transportation network. Extending the long tradition of American ingenuity in high-rise construction, the design solution is an innovative mix of architecture, structure, urban design, safety, and sustainability.
The tower’s spire reaches the symbolic height of 1,776 feet 541 meters, a nod to the year that the United States declared independence, and is topped with a large revolving beacon. The height of the parapet is similarly symbolic, matching the exact height of the original One World Trade Center. Sited north of the National September 11 Memorial, the tower rises from a cubic
base; its edges are chamfered back, resulting in a faceted form composed of eight elongated isosceles triangles. At its middle, the tower forms a perfect octagon in plan and then culminates in a glass parapet that is a 46-meter-by-46-meter square, rotated 45 degrees from the base. A luminous glass curtain wall sheaths the tower on all sides from the first office floor to the observatory. Designers worked with industry experts to develop glass of unprecedented scale that is capable of withstanding both wind loads at supertall heights and stringent security requirements. Insulated glass units span the full floor-to-floor height of each story with no intermediate mullions – a first in skyscraper construction. These glass units contribute to the tower’s crystalline appearance.
The cubic base is 57 meters tall and made entirely of reinforced concrete, providing a sturdy and secure support structure for the bottom of the building. To enhance the visual appeal of this feature, small stainless-steel panels are fixed to the exterior. Pivoted glass fins are arranged over these panels at varying angles, bouncing light in different directions and creating a corrugated texture for the faade at ground level.
“It is impossible to over-state the importance of One World Trade Center, from an architectural, urbanistic, engineering, symbolic, or emotional viewpoint. Fourteen years in the making, a void in both the physicality and psyche of a city has been repaired, to spectacular effect.”
Antony Wood, Juror, CTBUH
The tower structure is a “hybrid” system combining a robust concrete core with a perimeter ductile steel moment frame. The reinforced concrete core wall system at the center acts as the main spine, providing support for gravitational loads and resistance to wind and seismic forces. The core is compartmentalized with internal shear walls and houses the building systems and means of egress. The tower’s height and slenderness imposed stringent demands on its overall strength and stiffness. To meet those demands in an economical way, high strength 14,000 psi concrete was introduced for the first time in New York City.
The building uses new technologies to maximize efficiency, minimize waste and pollution, and reduce the impact of its development. Its seamless skin incorporates a visually subtle insulated spandrel, while allowing natural light to reach over 90 percent of the office areas, reducing the electrical lighting requirements and associated cooling loads, while improving the quality of the office space. The tower also uses 30 percent less water than the New York City Building Code requires for this type of building, in part by capturing and reusing rainwater for cooling the building and landscape irrigation. Low-energy equipment, such as variable-speed fans and pumps that are adaptable to varying occupancy levels, further maximize efficiency. Many of these systems are controlled using a high-tech building management system BMS, which optimizes energy use and indoor air quality based on data collected by thousands of sensors located throughout the building.
Along with energy savings, the building will capture energy through elevators with Variable Voltage Variable Frequency VVVF drives and hoist motors that produce energy through regenerative braking. Under certain conditions, the elevator motors turn into small generators that supplement power in the building’s power distribution grid, thus reducing demand for electrical utility power. Elevators also play an important role in the building’s evacuation scenarios, as five elevators are equipped to manage occupant egress in case of an emergency.
A significant amount of the materials used in the construction of the tower were made from post-industrial recycled content, including gypsum boards, ceiling tiles, and glass. The structural steel was produced from 95 percent recycled materials, and the building features “green concrete,” made from waste fly ash collected from coal plants, and slag, a by-product of the processing and refinement of various ores.
Jury Statement
The completion of One World Trade Center marks a definitive moment in skyscraper history. Far more than just a symbol of progress, wealth, or success, the tower embodies the resilience of a city, the trajectory of a nation, and the unity of a globalizing world that tracked its progress with bated breath. As such, the desi