Green buildings are considered more efficient than traditional buildings due to the incorporated techniques and the multidisciplinary specializations required to comply with their specifications, in addition to the advanced commissioning, which undergoes before handing over the buildings to the owners to ensure requirements conformance. As a result, the appropriate selection of a project delivery system acts as the essential factor that affects the performance of the project. This research aims at building a system that helps to select the best method to implement green buildings. Through studying the recent research approaches in project delivery systems, the factors that affect the selection of the optimal implementation method for green buildings have been identified; expert interviews have been done to study and analyze the main influential factors that affect the selection of the best method for implementing green buildings. The results of interviews indicate that the main influential factors are as follows: The occurrence of economic crises in the country, availability of financial capacity for the contractor and the owner, the lack of previous experience in similar projects, hiring an incompetent contractor, differences between design drawings among all disciplines, and providing qualified contractors, subcontractors, suppliers and craftsmen with sufficient qualifications early in the project. Depending on these main factors, a software system is built to choose the best delivery system for green building projects. This research encourages future works to focus on the quality and performance of green buildings and lays out the foundation for academic researchers to explore new techniques for evaluating the project delivery systems as well as supporting the decision-makers to choose the best.