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PurposeThis research aims to propose a comparative environmental analysis of conventional and prefabricated construction techniques utilizing a building information modelling (BIM) technique.Design/methodology/approachA set of indicators are selected to assess the environmental emissions throughout the construction life cycle, based on BIM platform. An existing project involving ten apartment buildings in Shanghai is selected as a case study.FindingsThe results reveal that prefabricated construction demonstrates environment-friendly performance with some exceptions of acidification and mineral resource consumption. Environmental impacts can also be further reduced by increasing the projected area ratio and percentage of project prefabrication.Originality/valueOverall, the proposed method can be used to identify relevant environmental merits and for decision-making of appropriate construction techniques in building construction projects.

Prefabricated construction has been widely accepted as an alternative to conventional cast-in-situ construction, given its improved performance. Great efforts have also been made to develop prefabricated construction technologies in China. However, there is a lack of an appropriate pattern for evaluating its comprehensive economic merits, and reasonable mathematical models for providing a comparative analysis of conventional cast-in-situ and prefabricated building projects have yet to be developed. Therefore, the research in this paper aims to comprehensively evaluate the economic benefits of implementing prefabricated construction techniques in order to surpass the economic barrier and promote the development of prefabricated buildings in China. The comprehensive economic evaluation is formulated in terms of resource-use efficiencies, project progress, and incentive policies. An apartment building in Shanghai is selected as a case study. Construction progress is simulated on the BIM platform when the same case study is rationally transformed from the prefabricated to the conventional cast-in-situ construction technique. The results reveal that the comprehensive economic merit can reach ¥739.6/m2 when selecting the prefabricated construction process. The economic benefit brought by shortening the construction period can be regarded as the most significant contributor. Yet, the current incentive policies only contribute 7.1% of the comprehensive economic evaluation. Overall, this research contributes an assessment framework for decision-making in the technique management of building construction. The BIM-based simulation approach can greatly help investors to identify the relevant economic factors and adopt the latest incentive policies.

In order to achieve the sustainable growth of its urbanization and natural resources, China has been making great efforts to develop prefabricated construction technologies. However, the high incremental cost of prefabricated buildings (PRBs) is a fundamental obstacle to the latter. The current study mainly focuses on analyzing the incremental cost of the on-site construction stage. It is hard to comprehensively identify the incremental cost composition without considering the incremental cost caused by prefabricated components (PFCs) production. Moreover, the results of incremental cost calculation are not accurate enough by comparing the cost of two similar but different PRB and traditional buildings (TRB), and the case-based calculation results suffer from a lack of representation. To address these issues, we first establish a two-dimensional incremental cost index system from the dimension of cost items and prefabricated technologies to study the incremental cost composition of the whole construction stage. Additionally, based on China’s latest policies documents, the applicability of incremental cost composition items can also be improved. Then a building information modeling (BIM)-based calculation model is presented to avoid the calculation error caused by comparing the cost of two different PRBs and TRBs. To validate the proposed index system and calculation method, an actual prefabricated project in China is also conducted as a case study. The results suggest that: (1) Incremental cost is composed of band bearing and retaining walls and inner walls PFCs production, PFCs hoisting and grouting, post-pouring concrete, and full decoration. (2) The BIM-based incremental calculation result of a PRB case from Shanghai is within the range of the national average PRB incremental estimation results. The incremental cost composition items and BIM-based calculation approach can greatly help investors to identify the largest increase in cost and make effective cost optimization strategies.

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