Greenhouse gas accounting and emission reduction in prefabricated construction: insights from extended input-output analysis

PurposeThe purpose of this study is to comprehensively evaluate the impact of the prefabrication rate on greenhouse gas (GHG) emissions and sustainability in prefabricated construction. In addition, it aims to identify the optimal prefabrication rate threshold that can promote the transformation of the construction industry toward more environmentally friendly practices.Design/methodology/approachThis study uses an interdisciplinary methodology that combines emergy analysis with an extended input-output model to develop a GHG emission accounting model tailored for prefabricated buildings. The model assesses various construction schemes based on different rates of prefabrication and uses the emergy phase diagram from ecological economics to quantify the sustainability of these schemes.FindingsThis study indicates that within a prefabrication rate threshold of 61.27%-71.08%, a 5% increase in the prefabrication rate can significantly reduce emissions by approximately 36,800 kg CO2(e). However, emissions begin to rise when the prefabrication rate exceeds this threshold. The case analysis identifies steel, concrete and electricity as the primary sources of GHG emissions, suggesting strategies for optimizing their usage and promoting the adoption of clean energy.Originality/valueThis study represents a novel tool for assessing the environmental impact and sustainability of prefabricated buildings. It offers scientific guidance for the construction industry's environmental protection and sustainable development strategies, thereby contributing to a transition toward more environmentally friendly practices.