Site layout planning (SLP) is an essential process that has a considerable influence on the safety, cost and duration of a construction project. Due to the complexity and the factors and variables needed in the process of SLP, the models discussed in the literature vary in their definitions and approaches towards solving SLP issues. This decreases the chances for those studies to build upon each other towards achieving a comprehensive model for SLP. This paper presents a methodology for developing an integrated Building Information Modeling and Geographic Information System model for SLP to fill portion of this gap by presenting a versatile and flexible SLP model. The said model is designed in a modular format to provide users with 4D visualization, a temporary facilities library, rule-based dynamic conflicts detection in 2D and 3D, route planning and hauling, and spatio-temporal analysis all in one environment. The presented methodology has the potential to provide an alternative that can lead to a unified solution for SLP by incorporating past solutions from the literature and serving as a foundation to provide answers to many of the SLP problems via a more detailed research in that area.