In this report, we present an automatic building extraction method from Digital Elevation Models (DEMs). The DEMs are generated using an algorithm based on a maximum-flow formulation using three-view images. First, the building footprints are extracted from the DEMs through an automatic method based on marked point processes : they are represented by an association of rectangles. Then, these rectangular building footprints are regularized by improving both the connection of the neighboring rectangles and the facade discontinuity detection. We obtain structured footprints. These footprints are used for the 3D-city modeling by considering a parametric approach based on a skeleton process which allows to model the rooftops.