MATERIALS WASTAGE IN CONSTRUCTION PROJECTS

The Sources And Causes For Materials Wastage In Construction Projects

ABSTRACT

Although waste minimization is identified as one of the key factors for achieving sustainability, the relative significance of construction waste sources and a comprehensive waste assessment system have yet to be developed. Implementing any successful waste minimization strategy during project execution requires the assessment of waste. Waste minimization has to be embedded as one of the project objectives for that lead to sustainability. An objective of this research study was to identify the most important sources of waste in construction and possible measures towards waste minimization in Singapore where construction is recognized as a major contributor to waste in landfill sites. The study was based on a postal questionnaire study of the larger construction firms. Design, operational, procurement and material handling attributes that lead to site waste were evaluated using statistical techniques. The study found that design changes while construction works are in progress is the most significant cause of waste generation at site. It is concluded that there is a need for the design and construction teams to interact closely to avoid unnecessary waste related to design problems. This would lend support to the country's effort towards sustainable development.

The Sources And Causes For Materials Wastage In Construction Projects

Background

The environmental implications of construction activity are now well known. The construction industry in particular and the built environment in general has been found to be among the main consumers of resources and energy. Moreover, the construction sector is reported to be generating unacceptable levels of material waste. In addition, it is well recognised that the Singapore construction industry has low productivity1 compared to the other sectors of the economy, such as manufacturing. The level of abortive work, due to a high extent of subcontracting is considered as a contributing factor to this phenomenon2. The vision outlined for the Singapore construction industry in the "Construction 21" blueprint is to become a "world class builder in the knowledge age" by, among other things, eradicating low productivity and undesirable waste generation which were reported to be prevalent in the construction industry.

This research study was undertaken to identify the factors which are responsible for the waste generated on construction sites in Singapore. This knowledge would guide waste minimization attempts at both the design and construction stages.

Construction Site Waste

Construction waste can be divided into three major categories: material, labor, and machinery waste. However, material wastage is of more concern because most of the raw materials from which construction inputs are derived come from non-renewable resources.

Although "waste" is a familiar term in the industry world-wide, it is difficult to compare construction waste figures from different construction sites due to a number of reasons, including the use of varying definitions; and the use of different estimation approaches, by different groups.

For this research study, the following definition of construction materials waste was adopted:

Ekanayake & Ofori Proceedings: Strategies for a Sustainable Built Environment, Pretoria, 23-25 August 2000 "Any material, apart from earth materials, which needs to be transported ...