The project dealt with the complex building task of the corner building. In the bourgeois architecture of the Gründerzeit, the corners of the urban block structures were often architecturally embellished by partly fantastic turrets; however, the corner solutions of the modern age - especially those of the 1960s to the beginning of the 1980s - frequently showed themselves as undifferentiated volumes, often not adequately designed regarding their prominent urban positioning, seeking the normative of the rows by continuing it again and again. As part of the B4 project, various corners between the Aachen Frankenberger Viertel and Elisenbrunnen were rethought. Depending on the location, residential and commercial buildings, small hotels with cafés, etc. were to be designed.