Knowledge of building techniques, materials and their decay is nowadays quite vast, as well as on the solutions and methodologies of a restoration project, which depends on the goal of the restoration itself. Even the choices on the new usage of historic buildings are often well considered. In the last few years, we have conducted some monitoring campaigns to obtain data related to four distinct buildings, differing in construction times, typology, location, current and historical uses. What has been discovered is that these buildings appear to be able to guarantee historical microclimates surprisingly overlapping to the parameters nowadays considered appropriate to conserve them and the historical patrimony they contain. In this article we show some explanatory results of four case studies from our research. The monitoring control, moreover, allowed us to develop the analysis further, from survey to virtual simulation. In this way it was possible to verify the effects of minimal variations in the architectural characteristics, such as opening or closing a window, covering an open yard, or else removing a cover, reducing the source of light etc. All of these managerial and architectural interventions have a significant effect on the indoor environment of buildings and can improve the conservation status of architecture, sometimes to such an extent that more costly and invasive restorations become unnecessary.