Activity-based life cycle analysis of a curtain wall supply for reducing its environmental impact

Significance Statement

The need to lower the environmental impacts of global warming gases has coerced the construction industry to endeavor to estimate and temper carbon dioxide emissions through product and process design. In this regard, several attempts have been suggested to evaluate the environmental impacts associated with construction materials and methods. The life-cycle assessment (LCA) technique has been extensively used for such purposes. This attributional LCA considers processes in a supply chain which allows users to pinpoint a process to improve so as to reduce its environmental impacts. However, the level of details adopted in traditional attributional LCA is aggregate and not appropriate for process improvement efforts in the construction project context which is mainly characterized as an intrinsic system.

Researchers led by Professor Yong-Woo Kim at University of Washington and Professor Jun-Seong Yi at Ewha Womans University in collaboration with Korea Institute of Civil Engineering and Building Technology introduced a revised attributional LCA technique that could be used in the construction supply chain where it could be employed for process control, which would in turn enable users to monitor and control the impacts of each process on the environment. The activity-based life-cycle analysis (ABLCA) method developed in their study adopts the methodology of the activity based costing system to carry out the assessment and analysis of environmental impact on the life cycle. Their research work is now published in Energy and Buildings.

The researchers undertook the task by carrying out a case study on the curtain wall supply chain. They carried out an analysis on the outcome of the inventory for each activity and an environmental impact assessment which showed that the curtain wall supply chain process made an impact on five environmental impact categories: acidification air, global warming air, HH criterial air; photochemical smog air and eutrophication air. The authors of this paper then extended the life-cycle analysis to include an environmental management tool which utilized a process map. The process map has five categories classified by emission amounts: most sensitive, sensitive, normal, less sensitive, and least sensitive.

The research team observed that from a detailed analysis on the production process, the existing technique analyzed the environmental impacts based on six life cycle stages while as the ABLCA technique included a more detailed analysis based on the process map which encompassed 28 activities. The outcome of the environmental impact assessment from the existing life-cycle analysis showed an overwhelmingly high value in ‘production and assembly’ stage in allenvironmental impact categories.The next highest value was in the ‘construction’ stage. The results from ABLCA show that transportation activity contributed higher environmental impact factorsthan aluminum sheet painting, curtain-wall assembly, shipment, and carry in on-site activities. The proposed method allows a project manager or environmental managerto work with a construction manager in charge of process management to reduce environmental impacts of activities which areclassified as critical.

Their research shows how ABLCA can be implemented and suggests how the results can be leveraged for managerial purposes assuming stakeholders involved in a supply chain are cooperative. However, it can be noted that the use of ABLCA outcomes can be challenging in managing construction supply chains where multiple entities are involved, each of which has its own commercial interests. The authors plan in future research to tackle the issue of implementation needs. The implementation issue also includes aligning interests among project stakeholders and integrating ABLCA results with traditional activity data.

About The Author

Yong-Woo Kim is a Professor and P.D. Koon Endowed Professor of Construction Management. He is a director of Lean Construction Research Lab (LCRL). His research emphasizes lean principles focusing on interdependency and uncertainty in construction supply chain networks as well as sustainable construction using lean construction principles.

About The Author

June-Seong Yi is a Professor of Architectural Engineering & Urban Systems at the Ewha Womans University of Republic of Korea. His main research interests are implementing Life Cycle Analysis in construction projects, building an intelligent system that efficiently responds to urban disaster, and providing comprehensive measures to improve safety and health in workplace.

Reference

June-Seong Yi, Yong-Woo Kim, Ji Youn Lim, Jeehee Lee. Activity-based life cycle analysis of a curtain wall supply for reducing its environmental impact. Energy and Buildings volume 138 (2017) pages 69–79.

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