The purpose of this research is to develop extensions and enhancements to Systematic Layout Planning (SLP) that allow more complex problems to be addressed during new facility layout construction. Specifically, the modified SLP technique allows for departments to be separated into subdepartments that may or may not necessitate placement beside other subdepartments of the same department. This scenario was previously unable to be addressed by traditional SLP. Also, the alternate subdepartment unit shapes of triangles and hexagons are tested against squares for their effect on the quality of the layout. Finally, new relationship variables, “viscosity” and “affinity” are defined to describe the intradepartmental and interdepartmental attraction, respectively. Layouts produced using the modified SLP technique are compared to those produced using traditional SLP on the basis of lowest cost and are computed using a tool created in Microsoft Excel. The modified SLP procedure produces layouts of statistically equal or lower cost than traditional SLP for the experimental data set.