It is becoming a popular practice for architects and HVAC engineers to simulate airflows in and around buildings by Computational Fluid Dynamics (CFD) methods in order to predict indoor and outdoor environments. However, many CFD programs are crippled by a historically poor and inefficient user interface system, particularly for users with little training in numerical simulation. This investigation endeavors to create a Simplified CFD Interface (SCI), a public domain program that allows architects and building engineers to use CFD without excessive training. SCI can be easily integrated into new CFD programs.