The urban concept of inserting a high-rise building and an adjacent plaza into dense urban surroundings, as used previously for the Seagram Building, is extended here to fill a larger site.
Two high-rise slabs in the heart of Chicago’s inner city are grouped around a single-storey square “pavilion” to create an extensive outdoor area. In contrast to the deep canyon-like streets of the surroundings, the buildings are perceived as freestanding elements in urban space. The large scale of the complex is apparent throughout, for example in the over eight-metre-high room height of the post office building.
Mies is known only to have commented on the project as follows: “We put the buildings so that each one gets the best situation and that the space between them is about the best we can achieve.”1 For him this was a question of proportions. Several different variants of the urban massing were developed. In addition to the asymmetrical arrangement that was eventually realised, a variant with a single tower and one with two identical building slabs arranged parallel to one another were presented. A fourth smaller building was eventually created to house the technical services. The resulting complex represents not only an architectural composition of abstract clarity but also a new urban concept in the city.
Although the façade articulation of the two towers is identical, they contain different functions. The 42-storey Kluczynski Building to the south contains offices for various federal authorities, while the slab-like 30-storey Dirksen Building contains courtrooms. The courtrooms, each two storeys high, are arranged above one another in the core of the building and are clad internally with stained walnut panelling. Lacking windows, they are lit by continuous illuminated ceilings made of a suspended aluminium grid of square panels. Offices are arranged next to the windows. Despite the uniform appearance of the exterior, the internal organisation of the building is very complex, with public and private areas kept strictly separate from one another: “The judges’ private elevators connect to underground parking; four special elevators carry prisoners to cells adjoining the courtrooms; jurors use the private corridor, as do judges, lawyers and staff; the public is restricted to the wide corridor serving the courtrooms.