Characterization of biomass-based materials for building applications: The case of straw and olive tree waste

•Biomass-based samples, containing olive and straw fibers, were tested; hygrothermal and physical properties were characterised.•Sorption curves, moisture effusivity and the ideal Moisture Buffering Value (MBVideal) were investigated.•The results show that the presence of the straw and the olive fibers enhances the hygrothermal properties of the materials.•Panels showed good sound absorbing properties depending on sample thickness.•The hygrothermal simulation of a flat demonstrates that, during winter, a significant reduction of yearly energy demand can be appreciated.