Thermal transmittance of historical stone masonries: A comparison among standard, calculated and measured data

- On-site campaign on several historic stone masonries.
- Comparison among standard and experimental thermal performance of stone walls.
- Standard calculations tend to overestimate the thermal performance of the traditional stone walls.
- Correspondences among geology of the territory, historical ages, thermal performances and heritage values.

The paper presents the results of an on-site campaign on several historic stone masonries, characterized by different heritage values, historical ages and intended use. Experimental data has been compared with the standard procedures normally used in the Italian legislation framework for assessing the thermal performance of existing masonries. Normally, the standard procedures tend to overestimate their thermal performance for security reasons. Similarly, wrong estimations or excessive simplifications have serious impact on the thermal assessment. For this reason, the paper presents an interdisciplinary assessment methodology for the thermal performance evaluation of the traditional stone walls located in Lombardy Region. The most important challenges are related to the correct definition of the wall morphology and thickness, the thermal properties of stone and the material proportions. The study shows a correspondence between the geology of the territory, the historical ages, the thermal performances and the heritage values of stone masonries. Furthermore, the proportion of materials, as well as the presence of internal air affect greatly the thermal performances.