The system will be constituted by a central core (a “super expert”) which co-ordinates a data-base, a thermal building behaviour simulating software and the “single expert system” that evaluate the damages of the buildings. One of these “single expert system” is worked out at the University “La Sapienza” of Rome. Its knowledge domains applied to enquiring into the causes of dampnes in building structures. Such a system will be able to simulate the knowledge required in the various stages of the building process, aiding the design process of building retrofitting.