Mitigating lifecycle GHG emissions of building sector through prefabricated light-steel buildings in comparison with traditional cast-in-place buildings

Prefabricated light-steel buildings (PLB), as a typical prefabricated building, are regarded as a potential solution in the sustainable building process. However, few researches have systematically identified the GHG emissions and reduction potential of PLBs from the whole lifecycle perspective. Thus, taking two low-rise buildings with similar building scales as the research objects, this study is designed to understand the lifecycle GHG emissions and reduction potential of PLB and traditional cast-in-place building (TCB) using Life Cycle Assessment method. The results show that the life-cycle GHG emissions of PLB and TCB are 2848.58 and 3055.11 kg CO2 eq. /m2, respectively, implying a 6.76% reduction potential of PLB. The use and operation phase of PLB (85.76%) and TCB (83.57%) accounts for the majority of GHG emissions. Compared with TCB, the GHG emissions in the construction phase of PLB are reduced by 12.45%, and its environment benefit in the end-of-life (EoL) phase is 170.05% higher. Aside from the use and operation phase, the reduction potential of PLB GHG emissions, compared with TCB, is 59.58%, in the construction and EoL phases together. Overall, this study evaluates PLB and TCB' GHG emissions, and finds sustainable buildings and effective reduction emission measures, which will promote the green development of construction industry in China.