The exact rebuilding of the church makes it necessary to employ state-of-the-art computer technology. CATIA, a software from French Dassault Systems, is suited for designing complicated 3-D geometries and multi-arched surfaces and includes all relevant features. In contrast to other programs, CATIA immediately works with a three-dimensional volume and full solidium model at scale 1:1 and facilitates the retrieval of all desired data, such as volumes, surfaces, weights and coordinates.