Willis Tower was $50 million. Since 2007, the building owners considered building a hotel on the north side of Jackson, between Wacker and Franklin, at the plaza that is the entrance to the tower's observation deck. The tower's parking garage is beneath the plaza. Building owners say the second building was considered in the original design. The plan was eventually cancelled as city zoning does not permit construction of such a tall tower there. Although Sears' naming rights expired in 2003, the building continued to be called the Sears Tower for several years. In March 2009, London-based insurance broker Willis Group Holdings
Willis Tower unfinished World Trade Center to become the world's tallest building. The height was restricted by a limit imposed by the Federal Aviation Administration (FAA) to protect air traffic. The financing of the tower was provided by the Sears company. It was topped with two antennas to permit local television and radio broadcasts. Sears and the City of Chicago approved the design, and the first steel was put in place in April 1971. The structure was completed in May 1973. The construction cost about US$150 million at the time, equivalent to $ million in 2019. By comparison, Taipei 101, built in