Integrating hygrothermal simulations with monitored data in extreme climatic conditions

Hygrothermal simulations for high-altitude heritage buildings are scarce and rarely validated. This study calibrates a Delphin model of mountain-refuge, a 1905 stone hut at 2871 m in the Dolomites, to support its internal insulation retrofit. Assumed boundary conditions were replaced with more than two years of monitored data, encompassing indoor and outdoor conditions and in-wall values across the cross-section. Three sequential steps were undertaken: inserting measured boundary conditions, clustering materials, and optimising critical properties, which reduced RMSE_RH from 11–35 % to under 4 % and RMSE_T from 5–6 °C to below 1.8 °C, demonstrating excellent agreement with monitoring. The well-calibrated model further enabled investigation of other orientations, assessing whether north-facing walls were exposed to high humidity risk. This validated workflow, linking targeted monitoring, precipitation correction, and material optimisation, offers both a structured guide and a practical precedent for future hygrothermal analyses and simulations of high-altitude masonry buildings facing retrofit decisions.