My Project 3 scope for the ARCH 652 class was to study how Building Information Modeling is used in analyzing the performance of the building in the early design phase, using various conventionally available simulation applications. The intent of this project was to study and identify what are the difficulties involved in utilizing the 3D models developed by the designers to perform energy analysis calculations and what information is missing in these applications while performing the calculations. In this study, I basically studied three different simulation applications namely: Green Building Studio (GBS), eQuest and EcoTec. The building design (3D model) was originally developed in the Revit platform which is quite commonly used by the designers now a days. The 3D model was then required to be transformed into different format, such as, gbxml or CAD in order to be accessed by other simulation applications.