To meet the national regulation on building energy needs while preserving the architectural heritage, the renovation of protected historic buildings implies to insulate internally their facades. However, it is a technically risky solution. This work is part of the European project RIBuild that develops guidelines to ensure moisture-safe solutions. For that purpose, historical buildings were monitored to confront the current state-of-the-art of hygrothermal simulations with in-situ measurements. To enforce these calculations, stones used in Swiss traditional construction were characterised, and materials' modelling were investigated. The results of the study will be integrated into a probabilistic web-tool.