Completed in
1973 after a little less than two and a half years under construction, this building became
The Tallest Building in the World, until
1996. In
1997, however, the
Council on Tall Buildings and Urban Habitat met in
Chicago to announce
new standards
w/r/t buildings. There are 4 categories, now:
1: structural or architectural top.
2: highest occupied floor.
3: top of the roof.
4: top of antenna.
The Tower now leads in the 2nd and 3rd. The Petronas Towers in Malaysia wins category 1, due to it's simply decorative spires. The World Trade Center buildings won the last one. This is obviously no longer the case.
The Sears Tower's roof is about 1,450 ft. in the air. The highest occupied floor is 1,431. (For reference, a quarter mile is 1454 ft.) It's 110 stories high, and takes up two blocks of street real estate, though there are 4.5 million gross square feet of office and commercial space. All told, antenna and all, it's 1,700 ft. tall.
The architectural firm that designed it was Skidmore, Owings, and Merrill.
The new antennas put in place March 8, 2000, weigh over a ton each, and will let Chicago be HDTV capable.
(Editor’s note: Sears Tower was renamed “Willis Tower “ in 2009, but only a tourist would call it by that name.)