Site layout planning is an important activity that involves identifying, sizing, and placing of temporary facilities within the boundaries of a construction site. The basic consideration in an effective site layout planning is the smooth and low-cost flow of materials, labor, and equipment within the site, in addition to satisfying various work constraints and safety requirements. This book presents a methodology for site layout planning. This methodology aims at supporting the three decisions related to site layout planning: identifying necessary facilities and determining their sizes; determining the inter-relationships among the facilities and optimizing the placement of the facilities on the site. The three decisions are mainly experience-based, however, each lends itself well to a different solution mechanism. Identifying the facilities and their sizes is knowledge dependent and as such a knowledge-based system is used in this process. Determining the desirability of having facilities close or apart from each other is also a problem that lends itself well to fuzzy-set applications. The optimization of facility placement on the site is done using genetic algorithms.