Impact of Project Delivery Systems on Cost Overruns of Green Building Projects: System Dynamics Approach

Cost overruns are one of the main obstacles facing the uptake of green buildings in the construction industry. A qualitative system dynamics approach was employed to understand the interrelationships of multiple factors causing such overruns based on literature collected in terms of the client and contractor and an active case study of a green building development complex in Qatar. Although studies had compared the cost performance of delivery systems, the study provides unique aspects related to the traits of delivery systems that reduce or increase such overruns. In doing so, latent factors that were not previously assessed in previous studies' approaches on delivery systems such as foreign currency collapse, corruption, and political impacts are considered. Although the model considered a green building in its work, the model can also be applied to less complex, conventional building projects, and yield important inferences on causes of cost overruns. The significance of the work enables testing different policies and scenarios in finding how cost overruns can be reduced.