Steel, Clay, and Glass: The Expressed Frame, 1897–1910

This chapter describes major structures built from 1897 to 1910, many of which used heavier fireproof jackets around steel frames, mandated by new codes. The 1893 Chicago Building Ordinance ended the laissez-faire attitude that had dominated the city's approach to building in the 1870s and 1880s. It featured an intensive focus on building safety, producing regulations that were progressive in their prescriptions for building envelopes but onerous in their limits on height. Collectively, these rules discouraged further experimentation with bay windows like those of the Reliance, instead favoring large, flat windows set into brick-jacketed steel frames. Curtain walls were further limited by Section 135, which stipulated walls of increasing thickness for higher buildings whether load-bearing or not. By 1903, window frames were also required to be of incombustible construction, eliminating wood in favor of cast iron or steel.