7 World Trade Center
The new 7 World Trade Center has 52 stories and is 741 ft (226 m) tall. The building has 42 floors of leasable space, starting at the 11th floor, and a total of 1,700,000 sq ft (158,000 m²) of office space. The first ten floors house an electrical substation, which provides power to much of Lower Manhattan. The office tower has a narrower footprint at ground level than its predecessor so the course of Greenwich Street could be restored to reunite TriBeCa and the Financial District.
David Childs of Skidmore, Owings and Merrill worked in conjunction with glass artist and designer James Carpenter to create a design that uses ultra-clear, low-iron glass to provide reflectivity and light, with stainless-steel spandrels behind the glass to help reflect sunlight. Stainless steel used in the building façade is molybdenum-containing Type 316, which provides improved resistance to corrosion. To enclose the power substation and improve its aesthetics, the base of the building has a curtain wall with stainless steel louvers that provide ventilation for the machinery. During the day, the curtain wall reflects light, while at night it is illuminated with blue LED lights. The curtain wall around the lobby uses heavily laminated, heat-strengthened glass that meets high standards for blast resistance. At night, a large cube of light above the lobby also emanates blue light, while during the day it provides white light to the lobby, and at dusk it transitions to violet and back to blue. Inside the main lobby, artist Jenny Holzer created a large light installation with glowing text moving across wide plastic panels. The entire wall, which is 65 ft (20 m) wide and 14 ft (4 m) tall, changes color according to the time of day. Holzer worked with Klara Silverstein, the wife of Larry Silverstein, to select poetry for the art installation. The wall is structurally fortified as a security measure.
The building is being promoted as the safest skyscraper in the U.S. According to Silverstein Properties, the owner of the building, it "will incorporate a host of life-safety enhancements that will become the prototype for new high-rise construction". The building has 2 ft (60 cm) thick reinforced-concrete and fireproofed elevator and stairway access shafts. The original building used only drywall to line these shafts. The stairways are wider than in the original building to permit faster egress.
7 World Trade Center is equipped with Otis destination elevators. After pressing a destination floor number on a lobby keypad, passengers are grouped and directed to specific elevators that will stop at the selected floor (there are no buttons to press inside the elevators). This system is designed to reduce elevator waiting and travel times. The elevator system is integrated with the lobby turnstile and card reader system that identifies the floor on which a person works as he or she enters and can automatically call the elevator for that floor.
Nearly 30 percent of structural steel used in the building consists of recycled steel. Rainwater is collected and used for irrigation of the park and to cool the building. Along with other sustainable design features, the building is designed to allow in plenty of natural light, power is metered to tenants to encourage them to conserve energy, the heating steam is reused to generate some power for the building, and recycled materials are used for insulation and interior materials.
7 World Trade Center construction in October 2004. Construction of the new 7 World Trade Center began on May 7, 2002 with the installation of a fence around the construction site. Tishman Construction Corporation of New York began work at the new 7 World Trade Center in 2002, soon after the site was cleared of debris. Restoring the Con Ed electrical substation was an urgent priority to meet power demands of Lower Manhattan. Because 7 World Trade Center is separate from the main 16 acre (6.5 ha) World Trade Center site, Larry Silverstein required approval only from the Port Authority and rebuilding was able to proceed quickly. Building Seven was not included in the original World Trade Center master plan by Daniel Libeskind, but was designed by Skidmore, Owings & Merrill under the leadership of David Childs, who largely redesigned the One World Trade Center.
Once construction of the power substation was complete in October 2003, work proceeded on building the office tower. An unusual approach was used in constructing the building; erecting the steel frame before adding the concrete core. This approach allowed the construction schedule to be shortened by a few months. Construction was completed in 2006 at a cost of $700 million. Though Silverstein received $861 million from insurance on the old building, he had $400 million remaining in mortgage to pay off. Costs to rebuild were covered by $475 million in Liberty Bonds, which provide tax-exempt financing to help stimulate rebuilding in Lower Manhattan and insurance money that remained after other expenses.
A 15,000 sq ft (1,400 m²) triangular park was created between the extended Greenwich Street and West Broadway by David Childs with Ken Smith and his colleague, Annie Weinmayr, of Ken Smith Landscape Architect. The park comprises an open central plaza with a fountain and flanking groves of sweetgum trees and boxwood shrubs. As the seasons change, so will the colors in the park, providing a natural complement to the tower. At the center of the fountain, sculptor Jeff Koons created Balloon Flower (Red), whose mirror-polished stainless steel represents a twisted balloon in the shape of a flower.