Fazlur Khan Converged Engineering and Architecture at the Top of the World

Fazlur Khan’s achievements as a structural engineer will forever be tied to Chicago’s Sears Tower (now called the Willis Tower), the tallest building in the world for a quarter century. But that long reign wasn’t stunt-architecture: The building, completed in 1973, represented a synthesis among structural possibilities, aesthetic exploration, and structural economy.

Working with modernity-defining architecture firm SOM, Khan’s early meetings with the Sears corporation in the late ’60s established that he wanted the building’s highest floors to have maximal space along the perimeter, accessing windows where the rents would be highest.