THE INSURANCE EXCHANGE. Tripartite Design

Chicago Skyscrapers ranging from the Chicago School "Rookery" and the "Auditorium" to the to the Classic Sky-scrapers of the early teens and twenties were usually of Tripartite Design. Simply said, they had a bottom, a middle and a top. In the earliest buildings (load bearing) the "bottom" tended to heavy stone or masonry. Later (with steel frame) a building's base could be more delicate, and a colonnade was often employed. In both cases, the "Skyscraper" had a flat roof.

The Insurance Exchange is an example of later Tripartite Design, an elegant interpretation of Classicism designed by Peirce Anderson after he became Daniel Burnham's chief designer. .

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The Skyscraper's ''CAP" (above) consists of a Loggia and a Cornice. The 'SHAFT' (below) makes up the carefully simplified middle. The "BASE" (bottom) is defined by the delicate colonnade.

Tripartite design was largely abandoned with the Zoning Ordinance of 1924 and the nearly simultaneous application of Art Deco concepts to Skyscraper design. (Not, however, without a long and successful "run") There are some notable transitional exceptions where "Towers" sit on a tripartite base. The Pittsfield Building, The Straus Bank, and the Wrigley Building are all important Chicago landmarks.

Incidentally, Charles Beersman's design for the Insurance Exchange's south addition includes foundations for one of those "Towers." A change in the weather, just after 1929 derailed that plan.