This thesis explores recycling wood-wool cement panel (WWCP) waste into innovative building materials, addressing the construction sector's sustainability challenges within the European Green Deal and the EU's 2050 climate neutrality goals. The study analyses waste management, develops sustainable cementitious binders from by-products, creates and characterises bio-composites, and performs a life cycle assessment (LCA) to validate material benefits. This approach provides a pathway for transforming WWCP waste into a valuable resource, promoting circular economy principles. Much of the research is dedicated to developing a method for effectively separating and reactivating hardened cement paste from WWCP waste. The study investigates various mechanical and thermal treatment methods to optimise the recovery of cementitious binders. Mechanical activation is explored through different milling techniques, including collision milling (at 25 and 50 Hz), planetary ball milling (at 300 RPM for 1-30 minutes), and vibration milling (for 5-20 minutes). These methods aim to fragment the hydrated cement conglomerates and release unhydrated cement minerals. For example, vibration milling for 20 minutes achieved a compressive strength of 1.6 MPa at 28 days. Thermal treatment methods are analysed to assess their impact on binder reactivation using a muffle furnace (from 300 to 1200 ℃) and a rotary kiln (at 450 ℃ and 900 ℃). The research evaluates the influence of processing parameters, such as milling duration and heat treatment temperature, on the properties of the reactivated binders, with muffle furnace treatment at 900 °C yielding the highest compressive strength of 19.6 MPa on the 28th day. The reactivated binders and recovered wood-wool are then utilised to develop and characterise bio-based composites for potential application in multilayered building panels. The research explores the relationship between material composition, mechanical properties, and thermal performance of the composites. Different formulations, incorporating alternative fillers like hemp shives (up to 75 %) and production line waste (PLW), are investigated to optimise the composites' properties for specific building applications. For instance, biocomposites with hemp shives demonstrated thermal conductivity as low as 0.052 W/(m·K) and densities from 170 to 780 kg/m³. The feasibility of producing self-bearing multilayered panels with enhanced hydrothermal performance is demonstrated, achieving compressive strengths up to 1.4 MPa. A comprehensive life cycle assessment (LCA) is conducted using the SimaPro platform and the NE 15804 + A2 V1.03 method to evaluate the environmental viability of the developed binders and the produced biocomposites. The LCA compares the environmental impact of the recycled materials with that of commercially available alternatives, such as rock wool and EPS, based on a functional unit of 1 m³ and a U-value of 0.18 W/(m²K). The analysis revealed that incorporating PLW can reduce the overall emission of 1 m³ of biocomposite by 26-58 % compared to cement-based alternatives. Overall, this research provides valuable insights into the effective recycling of WWCP waste and its transformation into sustainable building materials. The findings demonstrate the potential of reactivated binders, achieving compressive strengths from 0.5 to 19.6 MPa, and biocomposites with thermal conductivities ranging from 0.052 to 0.139 W/(m·K) to contribute to a more circular and environmentally responsible construction industry. By optimising waste separation and binder reactivation methods and carefully characterising the properties of the developed materials, this study offers a foundation for future research and practical applications, potentially transforming approximately 450 000 m³ of waste annually into raw materials for sustainable construction.