Embodied energy analysis of higher education buildings using an input-output-based hybrid method

During construction and operation, buildings consistently consume nearly half of the global energy supply, indicating a huge potential for reducing annual carbon emissions. This energy use includes operating energy and the three key life-cycle embodied energy components: initial embodied energy (IEE), recurrent embodied energy (REE), and demolition energy (DE). Embodied energy is consumed directly through processes and indirectly through products installed in a building. Unlike operating energy, measuring embodied energy is a complex, unstandardized, and very data-intensive process. Each available embodied energy calculation method differs in its data sources, system boundary coverage, and limitations. An IO-based hybrid (IOH) method could provide more complete, reliable, and study-specific results if appropriate improvements are made to the IOH model. In this study, we developed an IOH model for the United States' economy by integrating human and capital energy and computed the IEE of five higher education buildings. The results suggest that using an aggregated construction cost for calculating IEE may underestimate results in comparison to using disaggregated construction cost components because the calculated values of IEE increased significantly after the cost disaggregation. The relative proportions of different energy sources also changed considerably because of the cost disaggregation.