Using remote image acquisition, image processing, and computational systems and methods, it has become possible to obtain actual building dimensions that can be used to generate construction estimates for repairing or maintaining buildings. For example, actual roof dimensions can be used to provide a computer-based estimate of materials and/or materials overage needed. Instead of simply applying a generic overage percentage based on roof shape, a computer-based approach can take into account cut lines as a percentage of total roof area. The resulting computer-generated estimate is shown to be more accurate, less expensive, and faster than using a human on-site estimator.