In 1925 Mies van der Rohe was appointed by the Deutsche Werkbund as the director of a housing exhibition in Stuttgart, the Weissenhof Siedlung. Even if the site--a hilly plot of land on the northern outskirts of the city--was not particularly urban and the program of the exhibition focused on the individual dwelling, the project gave Mies the opportunity to develop a sort of a proto-urban site plan.
The scheme had to accommodate housing prototypes to be designed by almost twenty different architects, an international cast of characters that included emerging figures such as Le Corbusier, Hans Scharoun and Mart Stam, as well as members of the older generation like Peter Behrens and Hans Poelzig. In the site plan Mies articulates a series of terraced bands that absorb the particularities of the individual projects, most of them one or two stories. At the top, he places a much longer four-story block that serves as a backdrop for the overall project.
Needless to say that Mies reserves the design of the larger block for himself. But against the formal inflections of the other prototypes, his is the most restrained, a series of horizontal ribbons running the length of the uninflected volume. When you see it in the context of the nearby buildings of steep pitched roofs and punched windows, it appears as if Mies were drawing a line of reference, a datum, a "degree zero" for the project.