Towards improved construction waste minimisation: a need for improved supply chain integration?

A multi-stakeholder digital platform for regional construction and demolition waste management

Little attention has been paid to the interaction or synergy among construction and demolition (C&D) waste management stakeholders. A framework allowing for interaction among the various C&D waste players is especially important in regions with mature C&D waste infrastructure, where various recycling, reuse and disposal facilities are present. In such an expanded infrastructure, these facilities differ in terms of the C&D waste materials they accept, the nature of the waste accepted (sorted/unsorted), as well as the services they provide. This makes developing the optimal C&D waste management plan (WMP) more cumbersome for contractors. To address the challenges arising from the poor dynamics associated with the overarching waste management infrastructure, this paper proposes a novel digital platform, namely the 'Construction and Demolition Waste Management Kernel' (C&D WMK). The C&D WMK has three main objectives: it allows for data exchange between the different stakeholders, provides guidance to contractors when developing C&D WMPs and allows for governmental supervision and regulation. This paper introduces the concept behind the C&D WMK, presents the optimization model embedded in the system, and demonstrates its application in a case study leveraging real-world data. Finally, a scenario analysis is conducted to show how the C&D WMK can be used by governments to identify pitfalls in the state of practice at the regional scale, and to determine effective solutions to enhance the C&D waste management performance.

Modeling of 3R (Reduce, Reuse and Recycle) for Sustainable Construction Waste Reduction: A Partial Least Squares Structural Equation Modeling (PLS-SEM)

There is a lack of awareness and knowledge among the Malaysian construction industry about waste management reduction. Numerous nations worldwide have understood and have incorporated the concept of the 3R (reduce, reuse, and recycle) in waste management, and it has worked out well. This study investigated construction waste issues and developed a model for sustainable reduction by applying 3R using a partial least squares structural equation modeling PLS-SEM in Malaysia. The research methodology adopted the quantitative and qualitative approaches by sending a survey questionnaire to the relevant stakeholders to obtain their views or perceptions and interviewing an expert in the related field about waste reduction in the Malaysian construction industry. Three hundred thirty questionnaires were collected within six months of submission. The significant factors are determined using mean ranking for the reduce, reuse and recycle elements. Based on the results, the exploratory power of the study model is considered sustainable with R2 values of 0.83%. At the same time, the results of relationships between improving factors, policy-related factors, construction waste generated, and sustainable construction waste reduction were significant. Also, the findings revealed that the top factors for waste generation on reducing, reusing, and recycling are lack of design and documentation, and lack of guidance for effective construction waste-collecting. The paper will explore different and dynamic practices, such as recycling, reuse of construction waste management cost reduction, enabling stakeholders and managers to estimate and quantify the actual size of CWM costs and benefits for sustainable development goals.

BIM-Based Tools for Managing Construction and Demolition Waste (CDW): A Scoping Review

This article provides a picture of the latest developments in providing BIM-based tools for construction and demolition waste (CDW) management. The coverage and breadth of the literature on offering BIM-based tools and technologies for dealing with CDW throughout the whole life cycle of construction are investigated, and gaps are identified. Findings reveal that, although various BIM-based technologies are closely associated with CDW, much of the existing research on this area has focused on the design and construction phase; indeed, the problem of CDW in post-construction stages has received scant attention. Besides, the now available tools and technologies are lacking in cross-phase insights into project waste aspects and are weak in theoretical rigor. This article contributes to the field by identifying the intellectual deficiencies in offering BIM-based tools and technologies when dealing with CDW. So, too, it points to major priorities for future research on the topic. For practitioners, the study provides a point of reference and raises awareness in the field about the most advanced available BIM-based technologies for dealing with CDW problems.

Waste-efficient materials procurement for construction projects: A structural equation modelling of critical success factors

Albeit the understanding that construction waste is caused by activities ranging from all stages of project delivery process, research efforts have been concentrated on design and construction stages, while the possibility of reducing waste through materials procurement process is widely neglected. This study aims at exploring and confirming strategies for achieving waste-efficient materials procurement in construction activities. The study employs sequential exploratory mixed method approach as its methodological framework, using focus group discussion, statistical analysis and structural equation modelling. The study suggests that for materials procurement to enhance waste minimisation in construction projects, the procurement process would be characterised by four features. These include suppliers' commitment to low waste measures, low waste purchase management, effective materials delivery management and waste-efficient Bill of Quantity, all of which have significant impacts on waste minimisation. This implies that commitment of materials suppliers to such measures as take back scheme and flexibility in supplying small materials quantity, among others, are expected of materials procurement. While low waste purchase management stipulates the need for such measures as reduced packaging and consideration of pre-assembled/pre-cut materials, efficient delivery management entails effective delivery and storage system as well as adequate protection of materials during the delivery process, among others. Waste-efficient specification and bill of quantity, on the other hand, requires accurate materials take-off and ordering of materials based on accurately prepared design documents and bill of quantity. Findings of this study could assist in understanding a set of measures that should be taken during materials procurement process, thereby corroborating waste management practices at other stages of project delivery process.

Critical management practices influencing on-site waste minimization in construction projects

As a result of increasing recognition of effective site management as the strategic approach for achieving the required performance in construction projects, this study seeks to identify the key site management practices that are requisite for construction waste minimization. A mixed methods approach, involving field study and survey research were used as means of data collection. After confirmation of construct validity and reliability of scale, data analysis was carried out through a combination of Kruskal-Wallis test, descriptive statistics and exploratory factor analysis. The study suggests that site management functions could significantly reduce waste generation through strict adherence to project drawings, and by ensuring fewer or no design changes during construction process. Provision of waste skips for specific materials and maximisation of on-site reuse of materials are also found to be among the key factors for engendering waste minimization. The result of factor analysis suggests four factors underlying on-site waste management practices with 96.093% of total variance. These measures include contractual provisions for waste minimization, waste segregation, maximisation of materials reuse and effective logistic management. Strategies through which each of the underlying measures could be achieved are further discussed in the paper. Findings of this study would assist construction site managers and other site operatives in reducing waste generated by construction activities.

Development and validation of a building design waste reduction model

Reduction in construction waste is a pressing need in many countries. The design of building elements is considered a pivotal process to achieve waste reduction at source, which enables an informed prediction of their wastage reduction levels. However the lack of quantitative methods linking design strategies to waste reduction hinders designing out waste practice in building projects. Therefore, this paper addresses this knowledge gap through the design and validation of a Building Design Waste Reduction Strategies (Waste ReSt) model that aims to investigate the relationships between design variables and their impact on onsite waste reduction. The Waste ReSt model was validated in a real-world case study involving 20 residential buildings in Spain. The validation process comprises three stages. Firstly, design waste causes were analyzed. Secondly, design strategies were applied leading to several alternative low waste building elements. Finally, their potential source reduction levels were quantified and discussed within the context of the literature. The Waste ReSt model could serve as an instrumental tool to simulate designing out strategies in building projects. The knowledge provided by the model could help project stakeholders to better understand the correlation between the design process and waste sources and subsequently implement design practices for low-waste buildings.

System dynamic modeling on construction waste management in Shenzhen, China

This article examines the complexity of construction waste management in Shenzhen, Mainland China. In-depth analysis of waste generation, transportation, recycling, landfill and illegal dumping of various inherent management phases is explored. A system dynamics modeling using Stella model is developed. Effects of landfill charges and also penalties from illegal dumping are also simulated. The results show that the implementation of comprehensive policy on both landfill charges and illegal dumping can effectively control the illegal dumping behavior, and achieve comprehensive construction waste minimization. This article provides important recommendations for effective policy implementation and explores new perspectives for Shenzhen policy makers.

The effectiveness of Hong Kong's Construction Waste Disposal Charging Scheme

The Hong Kong Government introduced the Construction Waste Disposal Charging Scheme in December 2005 to ensure that disposal of construction and demolition (C&D) waste is properly priced to reduce such waste. The charging scheme is not only intended to provide an economic incentive for contractors and developers to reduce waste but also to encourage reuse and recycling of waste material thereby slowing down the depletion of limited landfill and public filling capacities. This paper examines the effectiveness of the charging scheme 1 year after implementation. A survey was conducted at Tseung Kwan O Area 137 and Tuen Mun Area 38, and daily C&D waste records were collected from landfills and public filling facilities between January 2006 and December 2006. The results of the survey show that waste has been reduced by approximately 60% in landfills, by approximately 23% in public fills, and by approximately 65% in total waste between 2005 and 2006. Suggestions for improving the scheme are provided.

Architects' perspectives on construction waste reduction by design

The construction, demolition and excavation waste arising in England was estimated at 91 million tonnes in 2003. The current thinking on construction waste minimisation is heavily focussed on several issues relating to physical construction waste and recycling guides. Indeed, much had been published on ways to improve on-site waste management and recycling activities but very few attempts made to address the effect of design practices on waste generation. However, there is a consensus in the literature that the architect has a decisive role to play in helping to reduce waste by focussing on designing out waste. This paper examines previous studies on architects' approach towards construction waste minimisation; and by means of a postal questionnaire, investigates: the origins of waste; waste minimisation design practices in the UK; and responsibilities and barriers within the UK architectural profession. The findings reveal that waste management is not a priority in the design process. Additionally, the architects seemed to take the view that waste is mainly produced during site operations and rarely generated during the design stages; however, about one-third of construction waste could essentially arise from design decisions. Results also indicate that a number of constraints, namely: lack of interest from clients; attitudes towards waste minimisation; and training all act as disincentives to a proactive and sustainable implementation of waste reduction strategies during the design process.