The goal of this project is the formulation a rigid, insulating, low-density wood composite, with physical and thermal properties comparable to fossil fuel derived foams. _x000D_ _x000D_ To achieve energy conservation standards mandated by certification agencies such as Passive House and LEED, high performance buildings require multiple shells of insulation â an inner shell that contains electrical and plumbing systems and an exterior, structural insulation located directly below outer facing of the building. In the United States this insulation shell is generally achieved using either rigid, low-density boards made from polystyrene foam â a $4B annual market. Low-density wood fiber (LDF) insulation boards are an environmentally sustainable product and could be manufactured cost competitively in the US. _x000D_ _x000D_ The technical hurdles that need to be addressed in this SBIR project to make that a reality are 1) Develop a fundamental understanding of the material variables that most impact the mechanical strength and thermal properties of low-density wood composites and 2) investigate the feasibility of replacing polyurethane binding agents with entirely renewable materials. The renewable binding agents we intend to investigate are nanocellulose and SynerXiD-WCB, which have been successfully used in other wood composites and can be derived from marginal wood and agricultural feedstoc