Quantification of building embodied energy in China using an input–output-based hybrid LCA model

• An input–output-based hybrid LCA model is developed to quantify the building embodied energy.
• Sensitivity analysis is used to extract significant energy paths.
• A comparison of the results from different LCA models verifies the advantages of the proposed model.
• Suggestions for reducing the building embodied energy are provided.

In China, a substantial amount of building embodied energy has been consumed as a result of rapid urbanization and the corresponding enormous construction workload. However, it is difficult for conventional life cycle assessment (LCA) models to completely and precisely quantify the embodied energy of a building. To solve this problem, this study develops an input–output (I–O)-based hybrid LCA model. In the model, sensitivity analysis is used to identify the key linkages between sectors that significantly affect the building embodied energy; subsequently, the significant energy paths are extracted. In addition, more reliable process analysis data are used as a substitute for partial energy path data. Using China's 2010 I–O table and process analysis data of primary construction materials, the building embodied energy in China in 2010 was quantified to be 1.3528 × 109 t of coal equivalent using the developed I–O hybrid LCA model. Based on the identification of the most intensive energy flows, various measures are proposed to limit the building embodied energy in China. A comparison of the results from different LCA models indicates that the I–O hybrid LCA not only ensures a complete assessment boundary but also improves the reliability of the results by substituting the energy path data with more precise physical process analysis data.