The Sassi of Matera are a very interesting example of a rocky settlement. The limestone walls often present high moisture content which negatively influences the room microclimate. In the first part of this paper, rooms without evident problems of moisture were analyzed for the purpose of carrying out a statistical analysis, to be repeated in analogous situations and to identify the distribution of what we can define as background moisture of the rocky installation. The knowledge of moisture, however, greatly influences the evaluation of heat loss since thermal conductivity of a material increases with an increase in the percentage of water that is contained within it. Consequently, the second part of the paper deals with thermal conductivi...