Thermal energy storage is an effective means to enhance energy efficiency in buildings, reducing energy consumption and decreasing greenhouse gas emissions. Phase change materials (PCMs) absorb or release large amounts of heat at a constant temperature while changing phases. When PCMs are at their phase-transitioning temperature, adding or removing heat results in no temperature change. This project will convert biomass wastes into specialty fatty acids and embed these into construction materials. Incorporating PCMs with a carefully selected melting point in buildings allows providing thermal comfort while reducing energy bills and environmental impacts. Biomass-derived PCMs will be embedded into medium density fibreboards (MDF) and particle boards produced from straw. This technology valorizes currently underutilized biomass residues, opens new opportunities for employment in the bioindustrial sector and green construction, and directly enhances the energy efficiency of buildings.