Several methods have been proposed to reconstruct houses from aerial images, most of them using rather specific models. These methods can not be applied when dealing with european-style houses and when a high level of detail is required. We present a system that works with rules instead of parameterizable shape models. This allows a larger variability of the objects to be extracted but also results in a more complex structure of the knowledge base and in a more sophisticated reasoning control. In the application section we demonstrate the use of such a system for reconstructing an object made up of planar surfaces from an aerial image. We will also explain how additional domain specific knowledge could speed up the extraction process and increase robustness.