Infrastructure projects often generate significant amounts of waste. However, research has focused so far mostly on the reactive treatment of waste, rather than its proactive prevention. Moreover, few previous studies have dealt with waste from infrastructure projects. This paper presents a method that can be used by project teams to identify both the causes of major types of waste in infrastructure projects, and the means to prevent its generation. The method is based on function modeling to support a detailed analysis of project activities that are critical in terms of their economic and environmental impact. The existing function modeling framework is expanded, to include a quantitative representation of material flows in the project’s supply chain. The proposed method was applied in a real project to verify its feasibility.