As one of the key sources of global carbon emissions, the low-carbon sustainable research of building systems is of great importance. This study, through life cycle ecological emergy and carbon footprint analysis, has confirmed the sustainability of building systems. It was found that the stages of building material production and operation have a significant impact on the system, with opposite trends. The increase in losses and consumption during system operation leads to a rise in the environmental load rate and a decrease in the sustainability parameter. The integration of energy storage modules effectively enhances the sustainability of the building system. In the initial 5 years, the emergy proportion of the building materials stage accounted for 63% of the building system, while the operation stage accounted for only 15%; however, as the years of use increase, these proportions change to 3.7% for the building materials stage and 96.3% for the operation stage, indicating that the contribution of the operation stage to the emergy of the building system gradually becomes dominant in the long term. The research results provide important insights for optimizing building design, highlighting the energy efficiency and environmental effects throughout the entire lifecycle of the building.