Construction Waste Reduction in Buildings through Modular and Offsite Construction: Fid-Bau Portal

Construction Waste Reduction in Buildings through Modular and Offsite Construction

Zhang, Yang / Pan, Wei / Teng, Yue / Chen, Siwei

Construction waste causes severe environmental problems. Reducing construction waste generation becomes a major policy measure of governments to achieve sustainable development. Offsite construction approaches are effective for reducing onsite construction waste. Nevertheless, there is a lack of a clear understanding of the types and amounts of construction waste that different offsite construction approaches can reduce. This study aims to investigate the performance of the modular construction (MC) approach in construction waste generation and reduction and how it differs from that of the nonmodular offsite construction (NMOC) approaches by comparing 59 selected cases of building projects that adopt these offsite approaches compared with stick-built construction. Results indicated that the adoption of offsite construction contributed to significant onsite construction waste reduction. On average, adopting MC reduced 78.8% of overall construction waste, outperforming other construction approaches. The level of prefabrication influenced onsite construction waste generation and reduction the most, followed by the other properties like building typology, density, and material used. Seven knowledge gaps were identified in the area of waste identification, quantification, and assessment. The findings demonstrate the advantages of using offsite construction in waste control and management and add to the existing body of knowledge on onsite construction waste generation and on waste reduction through adopting MC. The identified knowledge gaps point directions of future research on waste reduction through offsite construction.

The results of this paper suggest that the adoption of offsite construction can contribute to significant onsite construction waste reductions compared with conventional stick-built construction. Specifically, buildings adopting the modular construction (MC) approach can reduce overall construction wastes by around 80% and outperform other nonmodular offsite construction approaches, including those that adopt one-dimensional prefabricated beams and columns, two-dimensional prefabricated panels, or three-dimensional prefabricated pods, based on the analysis of 59 building cases covering different levels of prefabrication, building typologies, building densities, and building materials. This study contributes to the investigation of onsite construction waste by proposing a systematic assessment method addressing different construction waste types and assessment criteria. It facilitates a better understanding of the advantages of offsite construction in terms of waste control and management, especially MC, which was underexplored in the literature. Seven knowledge gaps were identified in the area of construction waste identification, quantification, and assessment. Addressing these knowledge gaps will contribute to better construction waste control and management, especially in MC projects.