Dynamic hygrothermal assessment of a stone wall for the installation of a novel bio-based multi-purpose insulation material

A new era of sustainable construction products centered on human comfort improvement and energy and environmental impact reduction is under development. In this context, biomaterials have an important role as they can reduce energy consumption and resource depletion from the perspective of a cir-cular economy. In this work, an external stone wall was analysed through WUFI Pro software in different configurations to assess its hygrothermal properties and evaluate the possibility of integrating a newly developed bio-based lignin-polyu-rethane foam panel from lignocellulosic sources. First, the stone wall was mod-elled varying the thickness, and the less performing thickness was studied by adding to the traditional stratigraphy two types of thermal insulation material with different water vapor resistance factors. The case study external wall typol-ogy was selected based on the review of representative typologies of Italian his-toric buildings. The component-scale performance was evaluated via WUFI Pro, which allows realistic calculation of the transient one-dimensional heat and mois-ture transport in building components. In this study, the analyses were carried out in the Italian climate zone D (Florence). Results pertain to the modelling of all the mentioned stone wall configurations and highlight the influence of the use of thermal insulation materials in historic building refurbishment for the improve-ment of the hygrothermal performance of building opaque envelope components.