Layout planning for construction projects comprises two tasks: facility layout planning (FLP) and material layout planning (MLP), which has significant impacts on project cost and time. FLP specifies where to position temporary facilities on the site, and MLP determines the position of the material in the storage yard. This study focuses on MLP and describes a simulation-based method to improve material yard layout. In this method, simulation is employed for modeling the material handling process to evaluate material handling time. Due to the broad domain of possible solutions, simulation is integrated with genetic algorithm to heuristically search for a near optimum material layout with the least haulage time. The implementation of the proposed method is demonstrated in a case study which shows the superiority of the developed method over conventional methods. This paper also discusses how the results of this research can contribute to FLP.