The paper presents an innovative semantic and parametric method to build 3D models to be used in cognitive-information systems. We integrated structured geometrical and documentary information resulting from multiple sources with the aim to enhance the knowledge of those sites within the frame of their historical evolution and their institutional management in a 3D GIS/DB. The developed applications were designed for different types of users, with a largely scalable interface, able to support different output devices and to work at different levels of iconicity. The system allows a full comprehension of the buildings in their own context, permitting to discover unknown relationships, to evaluate their architectural occupancy and to quickly access a complex system of information.