In cartographic presentations, spatial objects undergo a generalization process to adjust their graphical description to the respective scale and projection. One aspect is the geometric simplification, which, when performed autonomously on single objects, can lead to spatial conflicts with the entity’s neighbourhood. If a displacement is not desired or perhaps even prohibited, it is inevitable, that the generalized objects remain inside their original outlines as best as possible. In this paper, we present a generalization algorithm for 3D building models, an extension that adjusts the generalized shapes to better fit their original 2D ground plan and quality metrics that evaluate the generalization results with regard to the aforementioned requirements.