A Sustainability Analysis Based on the LCA–Emergy–Carbon Emission Approach in the Building System

Ecologically sustainable buildings and their carbon emissions are two popular ideas for building life cycle systems. It is a challenge to comprehensively assess the sustainability of building cases using two different methods. Based on over a decade of research, this paper attempts to explore the possibility of quantitatively integrating both approaches. In this study, we adopted the emergy method and carbon emission approach to assess and analyze a building system. In particular, similarities and differences have been identified through emergy and carbon emissions at each stage of the building’s whole life cycle. The results demonstrate that the building operation phase is the critical contributor (Approximately 79.6% of the total emergy and 97.9% of the entire carbon emission), which occupies the most emergy and carbon emission amounts of the whole building system. In order to improve the ecological sustainability of the building system, renewable energy subsystems are considered and explored. While the overall sustainability of the building system is enhanced, the new systems will aggrandize the carbon emissions. Therefore, the ecological sustainability of building systems and carbon emissions should be considered comprehensively, and the relationship between the two views needs to be balanced.