The imperative shift toward sustainable construction practices drives the exploration of alternative building materials, among which autoclaved aerated concrete (AAC) is emerging as a promising option. This research focuses on assessing embodied energy throughout the life cycle of residential buildings using a comprehensive life cycle assessment (LCA) methodology. The study specifically investigates AAC masonry as an infill material in reinforced concrete (RC) frame structures, highlighting its eco-friendly attributes. The present study conducts a detailed comparative analysis between RC frame buildings infilled with AAC block masonry and their counterparts using traditional clay brick infill. The assessment covers different life cycle phases, including extraction of raw materials, production, transport, construction, maintenance, and eventual demolition. By using LCA techniques, the embodied energy of both building types is quantified and compared, providing valuable insight into the environmental impact and sustainability of these construction materials.