In addition to looking at building structures and enclosures, the project I’m working on also looks at building planning, in particular the extents to which architects and clients went to ensure access to outside light and air.
John Wellborn Root’s essay, “A Great Architectural Problem,” written in 1890, said that skyscraper design was, at its most basic, the provision of adequate daylight to as many areas of the building volume as possible. Any areas without daylight, experience proved, would be otherwise unlettable. Several basic plan types emerged from this. Long, narrow lots produced slabs of offices, usually organized around a single double-loaded corridor. The Monadnock is a good example of this. Corner lots often produced L-shaped plans with the internal corner left open, sometimes with a skylit lobby or small banking hall below.
If the lot was large enough, though, architects tended toward a donut-shaped plan, wrapping two layers of offices and a double-loaded corridor around a hole in the middle that allowed interior offices access to light and air. The walls of these courts were typically clad in enameled brick, which reflected light and helped illuminate offices on lower floors. Burnham and Root used this type of plan most extensively, beginning with the Rookery in 1888 and continuing through the electrification period of 1908-1912. People’s Gas, shown here, is a good example of the type.
Light courts remained, however, even after electricity became a viable, economical alternative to daylight after 1912. In addition to illumination, light courts provided cross-ventilation. Office doors typically included transom panels at their tops that could be opened, permitting air to flow through relatively narrow floor plates. While mechanical ventilation was used in theaters and stores by the turn of the century, air conditioning did not arrive in Chicago until the early 1930s. Light courts, with their heavy penalties in loss of rental area, disappeared quickly and buildings like the Merchandise Mart ushered in an era of vast, electrically illuminated and mechanically ventilated floor plates.