Machine perception can benefit from the use of features extracted from data provided by a variety of sensor modalities. Recent advances in sensor design makes it possible to incorporate multiple sensors into vision systems for increased capability. Two important issues must be considered for the integration task. The sensors must be spatially coregistered and the phenomenologies must be compatible. In this paper we address these issues as they apply to the problem of automatic modeling of building structures from aerial views. We present a methodology to incorporate cues extracted from IFSAR (Interferometric Synthetic Aperture Radar) to significantly improve the performance and the quality of the results of an existing system that relies on electro-optical panchromatic images, while reducing processing time. Quantitative evaluations are given.