Life cycle assessment of a wood-aluminium window according to European norms

Wood-aluminium windows are increasingly valued for durability and energy performance, yet their overall environmental profile is strongly shaped by material choices, transportation, operational heat-losses, and end-of-life management. This study presents a comprehensive life cycle assessment of a wood-aluminium window manufactured in Slovakia, covering raw material extraction, manufacturing, distribution, use-related heat losses, end-of-life treatment, and benefits beyond the system boundary. Two scenarios were assessed: domestic delivery within Slovakia and overseas delivery to the United States. The assessment was carried out in accordance with the requirements of ISO 14040/14044 standards and was modelled and structured according to EN 15804 + A2 standard for environmental product declarations with modules A1-A5, B1, C1-C4 and D. The results indicate that upstream material production and manufacturing processes represent the dominant sources of environmental impacts. Transport-related impacts were comparatively small for domestic distribution but became substantially more influential in the overseas scenario, affecting multiple indicators beyond climate change, including acidification and eutrophication. Heat losses in the use phase contributed significantly to the overall impacts, highlighting the relevance of operational performance in addition to impacts associated with material production. End-of-life processing also played an important role, while recycling and energy recovery provided credits beyond the system boundary, underlining the mitigation potential of well-managed circular end-of-life routes. Overall, the study shows that the environmental performance of wood-aluminium windows is primarily driven by production, logistics, operational energy-related effects, and end-of-life infrastructure, identifying key leverage points for improving sustainability in building component design and supply chains.