ECO-COSTS PER VALUE RATIO ASSESSMENT OF CONSTRUCTION WASTE : A STUDY IN KLANG VALLEY, MALAYSIA

There is a need to quantify and assess the environmental impact of waste generated from construction activities. In terms of environmental impacts, Life Cycle Assessment (LCA) is commonly known as one of the most comprehensive and accurate tool for quantitative analysis of environmental impact over all life cycle stages of product s’ life. The latest breakthrough in LCA analysis is the eco-costing concepts. Eco-cost per value ratio (EVR) was introduced as part of LCA studies using economyecology approach, especially for consumer products. However, there are very few publications available on eco-costing and EVR applications in favor of construction waste generation. Therefore, this study shall assess eco-costs as the result or consequences of waste produced for the context of Malaysian construction industry, particularly in Klang Valley. This study focused on evaluation of eco-costs for waste generated during construction phase only, not the full life cycle. Major construction materials such as concrete, timber, reinforcement bars were taken into account. Construction projects covered in data collection process were residential, commercial, office buildings employing conventional and IBS systems within the area of Klang Valley in Malaysia. Eco-costs considered in this study include: the product unit cost, delivery cost/unit, cost of recycling/salvaging, cost of waste disposal, cost of landfilling (acquired from authority), cost of labor for waste collecting and sorting cost. Major data extracted include: Gross Floor Area (GFA); material order quantities and material workdone quantities from Bills of Quantity (BQ); construction debris disposal trip record; purchase and delivery costs and costs associated with waste generation; total project cost (contract sum). Results have shown that the wastage EVR benchmark for Malaysian construction industry shall lies at around 0.0024 – 0.0028 for typical multi-storey projects applying conventional and/or partial semi-IBS, and shall be considerably less, by up to 0.0014 for projects utilizing full IBS system or projects with exceptionally good waste management awareness and practice.