It has been demonstrated that by adding wood particles or wood fibres to a thermoplastic matrix, the stiffness, insulating properties and thermal stability of the resulting composite (wood-plastic or wood-polymer-composite, WPC) may be significantly improved. Simultaneously, production costs can be decreased due to the replacement of synthetic polymers with a renewable feedstock, i.e., wood. Assuming that in approximately 50-60 years, oil and fossil-fuel based products will no longer be available, the availability of the plastic window on the market can be significantly extended by adding at least 50% wood particles or fibres to a thermoplastic polymer matrix. The objective of this research project is to develop and manufacture a wood-plastic composite window profile for the European market. Our consortium will systematically investigate all steps required to produce a WPC window profile prototype, including identification of suitable raw materials for formulations (natural fillers or fibres, thermoplastics (PP, PE, PVC), coupling agents, UV protection agents, etc.), compounding, extrusion, die manufacturing, profile bonding, and development of suitable coatings. This project will contribute to the knowledge on WPC material properties and create novel applications for WPC. As significant growth potential for the European window industry has been identified, opportunities for sales of WPC windows as a substitute for PVC windows exist, especially in Eastern Europe. In the long term, theoretically, WPC windows could replace the total market share of PVC windows in Europe (over 40 %).