The historical former Police HQ building is the key point of identification in the new ensemble and defines the overall design. The integrating element is the theme of the black shimmering slate roof which is emulated in modified form in all the new buildings. The high-rise extends this theme skywards and establishes itself as the symbol of the ensemble in downtown Frankfurt. The superimposition of a contextual polygonal underlying figure and the transformation of an archetypal tower and/or roof shape gives rise to a highly varied volume.