In recent years, the growing emphasis on sustainable construction has led to an increasing body of research on the life cycle assessment (LCA) of buildings. While many studies have analyzed the environmental, economic, and social impacts of buildings throughout their life cycles, limited attention has been given to the sustainability implications of earthquake-induced repair activities. These repair activities significantly influence all three pillars of sustainability by causing economic losses due to repair costs and downtime, environmental damage through resource consumption and waste generation, and social impacts such as injuries and fatalities. Assessing the expected seismic damage of buildings requires understanding their structural behavior under seismic events, as insufficient resilience can lead to substantial damage and high repair demands. To minimize these impacts, researchers have examined various structural systems, often conducting comparative studies to identify those with lower economic and environmental costs and greater structural resilience. In the Iranian construction industry, a shift from steel structures to concrete structures has been observed in recent years due to factors such as material availability, cost, and advances in construction techniques. This transition underscores the importance of assessing the sustainability of these systems. This study aims to perform a comparative analysis of steel moment frames (SMF) and concrete moment frames (CMF) under seismic conditions, focusing on their environmental and structural performance. The findings will contribute to understanding which structural system offers superior sustainability, providing insights for future construction practices in earthquake-prone regions.
