Climate changes are altering patterns of energy supply and demand, which directly impact the need for adequate building insulation. This presents an opportunity for the development of new biomass-based materials as a renewable source aimed at reducing energy consumption and protecting the environment. The goal of this research is the application of wood sawdust, a waste biomass, as an aggregate for producing a new thermal insulation material. This experimental investigation represents an opportunity for the development of new biomass-based materials with the aim of reducing energy consumption and improving environmental protection. The biocomposite was tested in terms of thermal conductivity, and the obtained results were compared with the characteristics of commercially available thermal insulation materials. The performed analysis suggested that sawdust can be transformed into a valuable biocomposite for insulation purposes as an alternative solution.