The 1929 competition for the redesign of Alexanderplatz in Berlin finally gave Mies the chance to bring together at a truly urban scale the ideas about city and architecture that he had developed for most of the decade.
Unlike Pariser Platz or Leipziger Platz that were conceived as figural spaces, Alexanderplatz evolved as a large void in the city. And since the later part of the 19th century it had become a major traffic hub, with layers of transportation piling up at different levels. As planning director of Berlin, Martin Wagner developed a traffic scheme based on 100-meter circle that entrants to the 1929 competition had to incorporate in their proposals.
While the massing in all the other entries followed one way or another the geometry of the circle, Mies chose to deploy a series of discrete buildings that are deliberately independent, if not indifferent to the circle. Instead, the volumes align with the neighboring streets and present frontal elevations to main space of the square. In the renderings, all the volumes appear as glass buildings similar to the ones in the proposals for the Adam Department Store in Berlin and the Stuttgart bank of the previous year. Most of them are eight stories, except for a slender 17-story rectangular block that establishes something like a focus for the square (this taller block would have been located roughly where Behrens's Alexanderhaus is.) Some of the volumes are irregular in shape to complete the urban fabric while others--like the seven almost identical blocks to the south--are shaped with precise regularity.
It has been said that Mies's project anticipated the Plattenbau schemes of the DDR, but I think it's exactly the opposite, as the urbanism of Mies's Alexanderplatz is not denying but building upon the scale and structure of the existing city.
(By the way, this is the last of the "Mies and the City" series, at least for now.)