As Sears continued to offer optimistic projections for growth, the tower 's proposed floor count rapidly increased into the low hundreds, surpassing the height of New York 's 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 $830 million in 2018. By comparison, Taipei 101, built in 2004 in Taiwan, cost around the equivalent of US $2.21 billion in 2018 dollars.
how much did it cost to build the sears tower
about US $150 million at the time, equivalent to $830 million in 2018