A Study on Ecological Emergy and Carbon-Emissions-Coupling Sustainability of Building Systems

In the face of the increasingly deteriorating global environment, the sustainability of building systems has become a major research topic. This paper presents sustainability research on large-scale building cases from the perspectives of ecological emergy value and carbon emissions. Specifically, by calculating the emergy value and carbon emissions throughout the entire life cycle of the building system, a quantitative analysis of sustainability based on the LCA–emergy–carbon-emissions framework is completed. The results indicate that from the perspectives of both emergy value (over 80%) and carbon emissions (over 90%), the operational stage and the building-material-production stage are the controlling factors. Retrofit design strategies help enhance the sustainability performance of the building system, but different types of design strategies have different effects. The landscape-transformation-design strategy (strategy A) significantly improves the ecological sustainability of the building system, the equipment-improvement strategy (strategy B) helps reduce the carbon emissions of the building system, while the infrastructure-renewal strategy not only has a weaker impact on sustainability improvement but also generates the highest carbon emissions. Additionally, with the aim of controlling carbon emissions, the integration of solar clean energy sources contributes to the overall sustainability of the building system, providing references for architects and building managers.