Methodology for upstream estimation of construction waste for new building projects

摘要

Construction waste includes waste arising from construction works such as new build, renovation, demolition and road works. Through waste sorting and separation, inert material can be used to fill in reclamation sites; however, the non-inert portion of the construction waste still goes to landfills. However, Hong Kong is running out of landfill space. When determining reduction and management strategies for construction waste, the Government's objectives are to reduce waste generation, maximize reusing and recycling and reduce the intake of mixed construction waste at landfills. In order to develop and implement the waste reduction and management strategies at project level, proper quantification of construction waste generation is a prerequisite. Our research reveals that limited information is currently available for understanding the magnitude and composition of construction waste and for preparing an appropriate construction waste management plan for a project on new or existing facilities. To bridge the gap, the aim of this research is to present a comprehensive and practical approach for estimating the construction waste for building projects once detail design is carried out for new build or major retrofitting works. The estimation of waste quantities is based on the actual design information available from tender or contract documentation for a project at the upstream stage (a full set of bills of quantities classified under standard format). The proposed methodology of aggregating wastages accruing to quantified elements for a complete building has its advantages over a ball park figure established through indexing or other methods as proposed in existing literature, in terms of ensuring accuracy and maximizing the use of available design information whilst the workflow is uninterrupted.Three representative case studies with different formwork and facade systems are depicted to high-light the significant effects on waste generation in otherwise similar construction projects. (C) 2019 Elsevier Ltd. All rights reserved.