This chapter explores the role of rural areas in advancing the European Green Transition by leveraging local resources for sustainable construction. It examines how bio-based materials derived from agricultural and forestry waste can be a valuable opportunity to decarbonize the building industry while fostering circular economies and resilient rural communities. The research adopts a multiscale, multidisciplinary approach to identify strategies for selecting potential local bio-based resources for adapting rural buildings to climate change, preserving cultural heritage, and improving energy efficiency. Methods include the classification and quantification of biomass, GIS-based material flow analysis, and environmental, and socio-economic assessments, such as Life Cycle Assessment and Multi-Criteria Decision-Making. The chapter highlights frameworks for integrating bio-based materials into rural construction, emphasizing their regenerative potential and alignment with circular economy principles. Case studies, including Valmalenco in northern Italy, demonstrate replicable workflows for transforming organic waste into construction materials, from waste quantification to sustainability evaluation. The research underscores rural regions' pivotal role in creating low-carbon, resilient built environments and ecosystems.