With an increased emphasis on sustainable buildings, building owners have begun to demand better methods of predicting building system performance, in particular with respect to energy. A variety of energy modeling programs have been developed to meet the growing interest in energy efficient buildings. However, the energy modeling software is typically cumbersome to use and was designed to compare various system options for new construction. The retrofit sector of the building industry lacks a clearly defined energy auditing process and energy modeling tools developed specifically for retrofits. This research develops high level process models and the necessary information exchanges which can be utilized to develop a building typology tool for retrofit buildings. The study defines: (1) the need for a standard and transparent energy auditing process and modeling tools intended specifically for commercial retrofits; (2) typical vs. desired information flows (through an industry workshop) and a high level process model; and (3) initial criteria for a retrofit specific energy analysis methodology by determining which outputs and inputs are needed at the various stages to perform an accurate and useful energy assessment.