Carbon Emission Assessment for Steel Structure Based on Lean Construction Process

Lean principles provide improvement to the efficiency of construction by synchronizing the process of building and eliminating waste, which in turn can have a positive impact on the environment. This is generating a growing interest in linking the relationship between lean and low carbon. The authors compare the carbon emission in the truss construction process of a steel structured building in China optimized by lean principles with the original process. A partial life cycle assessment (LCA) framework is used to calculate the embodied carbon of materials, energy consumption of transportation from cradle to site, energy consumption of construction equipment and disposal of construction waste. This confirms through case study and measurement what had previously been proposed and adds the aspect of site efficiency into the current method for life cycle assessment of carbon emission. The results show that the lean process had an embodied carbon of 5532.1t CO2e delivering a reduction of 43t compared to the original process, demonstrating lean interventions can have a positive impact on the environment. This study establishes the link between the efficiency of the construction process and low carbon using empirical evidence demonstrating that contractors can use lean principles in their construction processes to improve efficiency and reduce carbon emissions as a result.