Influence of Design Complexity on Energy Demand in Window Assembly

Lifecycle impact assessment of façade systems is challenging due to uncertainties in fabrication processes, assembly energy requirements, and modeling assumptions. Conventional lifecycle assessment (LCA) methods frequently estimate fabrication energy based solely on material mass, neglecting the effects of system configuration and manufacturing complexity. Although these simplifications facilitate standardization, they may introduce substantial inaccuracies when applied to complex façade systems.

This research examines the influence of design complexity on fabrication energy demand and associated Global Warming Potential (GWP) in aluminum façade products. A process-based modeling approach was developed, utilizing data from Sphera LCA for Experts and on-site observations at a Skyline Windows manufacturing facility. Comparative analysis of façade systems with varying complexity indicates that fabrication energy is more significantly affected by the number of discrete components and machining operations than by material mass alone. The findings reveal that simplified mass-based methods can both overestimate and underestimate fabrication impacts depending on system configuration, with the greatest discrepancies observed in more complex assemblies. These results underscore limitations in current Environmental Product Declaration (EPD) methodologies and demonstrate the necessity of incorporating process-level parameters into LCA models. This framework offers a more accurate method for evaluating fabrication impacts in façade systems and enhances the reliability of lifecycle assessments for complex building components.