Consideration of the environmental cost in construction contracting for public works: A + C and A + B + C bidding methods

Growing concerns about sustainable development have brought about an urgent need to develop global efforts to mitigate environmental impact. Although construction projects and their related activities consume much energy and generate a significant amount of greenhouse gas (GHG) and other diesel emissions, the efforts to mitigate these emissions remain at an early stage. To address this issue, this paper explores opportunities to consider contractors' green capabilities during the bid evaluation phase. Based on reviews of the success story of the A+B bidding method, this paper suggests a modified bidding system in which contractors bid on the cost (part A) and environmental cost (part C) or on the cost (part A), time (part B), and environmental cost (part C) for public projects. An application of the proposed bidding methods is described using a bid for a highway reconstruction project. This case study reveals the potential impact of environmental cost criteria on the selection of a winning bid. The result of this case study indicates that the proposed bidding methods can offer bidding incentives to create sustainability initiatives for public works contractors.