Quota-based carbon tracing model for construction processes in China

Carbon emissions contribute substantially to climate change. Many researchers believe that the construction industry can contribute significantly to carbon dioxide reduction through cleaner and more sustainable building production and construction, e.g. low energy building design and the use of low carbon materials. Nonetheless, the environmental impacts associated with construction process should not be underestimated. Despite that, as construction process is complex and involves many participants, the calculation of carbon emissions during the construction process is never an easy task. Divergence and limitation are found in both the system boundary and carbon sourcing method. This research aims to resolve the problem and facilitate construction managers to identify carbon emissions so as to optimize them through better construction arrangement. In this paper, the system boundary of the construction stage is first defined and the related activities being included in the construction process are identified. A methodology of establishing the sources of carbon emissions during the construction process based on a quota-based method of China is proposed. The calculation model for carbon emissions is established according to the traditional emission factor approach with some modifications. The carbon emitted during the construction process of a case teaching building is calculated using the proposed quota-based carbon tracing (QCT) model. The QCT model not only provides a systematic framework for the tracing of carbon emissions, it could also help construction managers identify low carbon construction methods and logistics schedule in order to maximize the carbon reduction opportunity during the construction stage.