Recent years have witnessed a wide application of green buildings in the world. Properly measuring the performance of green building projects has been the cornerstone of governmental policy-making on energy saving and carbon reduction, and it has been playing a crucial role in the formulation of business competitive strategies. In this study, multidimensional evaluation indicators are identified. A benefit-output model composed of physical and currency indicators is proposed using gray relational algorithm to make quantitative evaluation of multiple schemes for green benefit of construction projects. Through the comparison of three cases in China, the proposed model is found to be more stable, reliable, and effective than others including grey cluster evaluation and data envelope analysis,presenting a multi-dimensional concept of green buildings and offering a useful framework for application in other contexts.