Experimental thermal performance of plastic 3D-printed insulation panel for building renovation

The built environment accounts for a substantial portion of global resource consumption, and the drive to renovate existing buildings for zeroemission performance is expected to further increase material demand. Simultaneously, plastic pollution remains a critical ecological challenge. Integrating plastic waste into construction materials offers a promising strategy to mitigate environmental impacts, promote recycling, and advance material circularity. This study investigates the development and thermal performance of a 3D-printed insulation panel fabricated from PET plastic with a design compatible with recycled materials. The panel features a 3D-printed PET structure with internal cavities that can be filled with recycled HDPE, leveraging both the design flexibility of additive manufacturing and air and plastic infill insulating properties. Thermal performance was evaluated using the standardised hotbox method, and results demonstrate that the panel achieves competitive U-values of 0.46 W/(m 2 K) and 0.35 W/(m 2 K) for the empty and plastic waste-filled samples, respectively. Overall, the findings highlight the potential for 3D-printed plastic panels to enhance building energy efficiency while diverting plastic waste from the environment and contributing to sustainable building renovation.