Willis Tower
The Willis Tower, formerly and still commonly referred to as the Sears Tower, is a 110-story, skyscraper in the Loop community area of Chicago in Illinois, United States. Designed by architect Bruce Graham and engineer Fazlur Rahman Khan of Skidmore, Owings & Merrill, it opened in 1973 as the world's tallest building, a title that it held for nearly 25 years. It is the third-tallest building in the Western Hemisphere, as well as the 26th-tallest in the world. Each year, more than 1.7 million people visit the Skydeck, the highest observation deck in the United States, making it one of Chicago's most popular tourist destinations. Due to its height and location, the tower is visible from a great distance. The building has appeared in numerous films and television shows set in Chicago.
The building occupies a site bound by Franklin Street, Jackson Boulevard, Wacker Drive, and Adams Street. Graham and Khan designed the building as nine square "tubes", clustered in a 3×3 matrix; seven of the tubes set back at upper floors. The tower has 108 stories as counted by standard methods, though the building's owners count the main roof as 109 and the mechanical penthouse roof as 110. The facade is made of anodized aluminum and black glass. The base of the building contains a retail complex known as the Catalog. The lower half of the tower was originally occupied by retail company Sears, which had its headquarters there until 1994, while the upper stories were rented out.
The structure was known as the Sears Tower from its construction until the naming rights were included in a 2009 lease with the Willis Group. Local area residents still refer to the building by its old name., the building's largest tenant is United Airlines, which occupies around 20 floors. Other major tenants include the building's namesake Willis Towers Watson, and law firms ArentFox Schiff and Seyfarth Shaw. Morgan Stanley became the building's fourth-largest tenant in 2017.
History
Planning
Site selection
had occupied an office complex on Chicago's west side since 1906. The existing offices were inadequate by 1966, prompting Sears executives to begin searching for a new site. By 1969, Sears was the largest retailer in the world, with about 350,000 employees. Sears executives quickly determined that a new headquarters complex in the suburbs was infeasible, since it would require relocating about 7,000 employees. Instead, Sears executives decided to consolidate the thousands of employees in offices distributed throughout the Chicago area into one building on the western edge of Chicago's Loop.Sears asked its outside counsel, Arnstein, Gluck, Weitzenfeld & Minow to suggest a location. The firm consulted with local and federal authorities and the applicable law, then offered Sears two options. The first option was the Goose Island area northwest of the Loop, but Sears's vice president of real estate, Matthew J. Stacom, rejected this proposal. The other was a two-block area in the Loop, bounded by Franklin Street on the east, Jackson Boulevard on the south, Wacker Drive on the west, and Adams Street on the north. Though the site was more centrally located, it was also relatively small, with about. Bernard Feinberg, Albert I. Rubenstein, and Philip Teinowitz had assembled that site over the previous five years, but they had failed to acquire a neighboring lot from bus company Greyhound Lines.
Feinberg, Rubenstein, and Teinowitz then bought options for three adjacent lots. Under the terms of each option, unless the three men were able to acquire at least one of the lots within 90 days, all three options would be forfeited. Ultimately, Sears acquired the Loop site in 1970. Sears then obtained permits to close down one block of Quincy Street, which bisected the site from east to west. Attorneys from the Arnstein firm, headed by Andrew Adsit, began buying the properties parcel by parcel. Sears purchased 15 buildings from 100 owners and paid the government of Chicago $2.7 million for the block of Quincy Street that was to be closed down.
Design process
Sears executives estimated that their new building would need about, split into 70 stories with each or 60 stories with each. Sears commissioned architecture firm Skidmore, Owings & Merrill to design the tower. SOM was also the lead structural engineer, and Jaros, Baum & Bolles provided MEP engineering.Sears planned to move its merchandise group into the building initially, renting out the remaining space to other tenants until needed. Sears executives were accustomed to large floor areas of at least, but SOM architects raised concerns that the large floors would be unattractive to smaller tenants. A subsequent proposal called for two buildings connected by a footbridge, which would respectively contain and on each floor, but this was also infeasible.
Some floors were designed with smaller footprints to attract prospective lessees, so the building's height was increased to meet Sears's floor-area requirements. Architect Bruce Graham and structural engineer Fazlur Rahman Khan, both of whom were partners with SOM, proposed a tower with floors in the lower part of the building, as well as a series of setbacks with gradually tapering floor plates, giving the tower its distinctive look. During the design process, one of the architects reportedly pulled out nine cigars and staggered them vertically until the pair both agreed to the arrangement. This allowed Sears to occupy the large lower stories, while providing more conventional office space that could be rented out on the upper stories. The firm of Saphier, Lerner, Schindler was responsible for determining Sears's space requirements and designing furniture for the company. It conducted a year-long study to determine how 16 of the company's departments should be laid out within the building.
As Sears continued to offer optimistic growth projections, the height of the proposed tower also increased. Under Chicago's relatively lax zoning laws, the site could theoretically accommodate a 300-story building with. In practice, most potential tenants did not want excessively high offices. Additionally, the Federal Aviation Administration restricted the height of structures in the area to protect air traffic. FAA officials publicly denied that they had imposed a height limit; however, the area's minimum safe altitude would need to be raised by if the building was just taller. Plans for the tower were announced on July 27, 1970. The building would contain 109 stories as measured from Wacker Drive and 110 stories as measured from Franklin Street. This would make Sears's new tower the tallest in the world, as measured by roof height, although New York City's under-construction World Trade Center Twin Towers would have a taller antenna. Although the Sears Tower would contain of space, only about would be used as offices.
Construction
Early construction
Work on the building's foundation commenced in August 1970. Contractors excavated the lot to a depth of, and they removed of dirt from the site. By that November, Spencer, White & Prentis Inc. was excavating a trench around the site, measuring deep and across. The contractors then built a slurry wall within the trench, made of concrete and reinforced steel. Workers used steel bracing to prevent the slurry wall from collapsing inward, then used caissons to drill 201 holes into the ground. They also rerouted a sewer that had run underneath Quincy Street, which was to be closed permanently as part of the tower's construction.The Diesel Construction Company was hired as the Sears Tower's general contractor. Sears, Roebuck & Co. chairman Gordon M. Metcalf installed the building's first steel beam at a ceremony on June 7, 1971. The project employed 2,000 workers. To accelerate the building's construction, a concrete plant was built in the building's basement, allowing workers to pour one-third of a concrete floor every day. Contractors built two temporary kitchens on the site for workers, and telephone and loudspeaker systems were installed on every floor to allow workers to communicate. In addition, contractors installed temporary generators that could supply up to simultaneously; during the winter, most of this electricity was used to heat the exposed steel beams on the lowest five floors.
Broadcast-signal controversy
By late 1971, Chicagoland residents and broadcasters had raised concerns that the new Sears Tower would disrupt television broadcasts. According to one estimate, the building would obstruct television signals for 15 percent of Chicagoans and cause "double images" for another 20 percent, primarily affecting communities to the northwest and southeast. The same year, officials of the village of Skokie, northwest of Chicago, threatened to request an injunction to prevent further construction. In response to these concerns, Sears started researching methods to reduce the tower's effect on broadcast signals. Variety magazine stated that the Sears Tower did not interfere with broadcasts on its own, since several shorter towers in the Loop also interfered with broadcast signals. Nonetheless, the Illinois Citizens' Committee for Broadcasting filed a formal complaint with the Federal Communications Commission in February 1972.The first lawsuit against the building was filed by the state attorney in neighboring Lake County on March 17, 1972. A second suit was filed on March 28 in Cook County Circuit Court by the villages of Skokie, Northbrook, and Deerfield, Illinois. Sears filed motions to dismiss the Lake and Cook County lawsuits, which both sought to cap the building at 67 stories. Sears studied the possibility of erecting antennas atop its tower in April 1972, and the tower's construction continued, even as decisions on both lawsuits were delayed. At the end of the month, the company applied for permission to increase the building's height limit by and install a new antenna, although eight of Chicago's ten television stations criticized the plan. On May 17, 1972, Judge LaVerne Dickson, Chief of the Lake County Circuit Court, dismissed the suit, saying, "I find nothing that gives television viewers the right to reception without interference." By then, the building had reached the 58th story. The Lake County attorney appealed to the Illinois Supreme Court. In his decision on June 12, Judge Charles R. Barrett contended the plaintiffs did not have a right to undistorted television reception.
Meanwhile, the FCC declined to act on the height dispute on the grounds it did not have jurisdiction. The FAA approved the antennas atop the tower in June 1972, and the Illinois Supreme Court affirmed the previous rulings by Lake and Cook County circuit courts at the end of the month. Work was temporarily paused that July due to a labor strike. The next month, Sears formally announced plans for broadcast antennas on the tower's roof, and the company offered to spend $5 million to help relocate broadcast stations to the Sears Tower. The United States Court of Appeals for the Seventh Circuit upheld the FCC's decision in September, and the United States Supreme Court refused to hear an appeal of the Seventh Circuit's decision that November.