Cost and time overrun analysis for green construction projects

Green construction projects are initiated in complex and dynamic environments resulting in circumstances of high level of uncertainty with respect to cost and duration. This is attributed to the fact that construction of green buildings requires stricter norms in terms of environmental conservation, carbon emission, construction footprint, pollution, etc. which can cause an addition to ‘cost and duration’. This paper describes a systematic way to identify and quantify uncertainty in the green construction process based on the LEED rating system adopted by the Indian Green Building Council (IGBC). The system incorporates knowledge and experience acquired from many experts, projectspecific information, decision analysis techniques, and a simulation model to predict risks for different green ratings in the construction schedule at the conception stage of a project. The model provides sensitivity analysis for different outcomes wherein the effect of critical and significant risk factors can be evaluated. The study focuses on lessons learned from past projects and describes a risk assessment process involving typical inputs and expected outputs.