Biogenic Local Waste for the Refurbishment of Rural Heritage: the Gualtieri Case Study (Lombardy, Italy).

Can rural buildings be refurbished by exploiting natural waste from local productions? This research aims to achieve implementation and sufficiency objectives by focusing on existing building refurbishment, efficiency improvement, and local natural resources exploitation. The solution being explored is the use of bio-based building materials, which, if well-designed, can offer low or even positive environmental impacts. To avoid land use and ensure not to compete with the food and biofuel sectors, the research focuses on organic waste in a circular approach. The research investigates a replicable workflow for using local bio-based waste in rural refurbishment, from the quantification of waste to the evaluation as building components, to finally assess the impact of their application. The contribution analyzes the state of the art, highlighting the lack of an established methodology for using natural waste in construction. The final goal is to facilitate the integration of these materials into the local construction sector. A case study has been presented to consider a specific geography and government system, starting with examining the Valmalenco Mountain Valley in northern Italy and hypothesizing the refurbishment of the Gualtieri village as a pilot project. The research employed Life Cycle Assessment to investigate the sustainability of different refurbishment scenarios for the case study, employing the semi-static method to determine GWP. Two tiers of study ensued: a primary comparison of biogenic insulation materials based on performance, impact, and cost, and a secondary analysis of three technologies, both conventional and innovative. Finally, a comprehensive examination of impacts was conducted and contrasted with the CasaClima protocol’s national performance scale, yielding positive verification.