Evacuation models, including engineering hand calculations and computational tools, are used to evaluate the level of safety provided by buildings during evacuation. Building designs, occupant procedures, and notification technology are based on the results produced from these models, primarily evacuation time results (i.e., how long building occupants will take to evacuate a building). However, there is a lack of available data and theory on occupant behavior for use by evacuation models when producing evacuation time results. In lieu of data and theory, evacuation models make assumptions and simplifications about occupant behavior (i.e., what people do during evacuations) that are unrealistic and are likely to produce inaccurate results. Also, evacuation models depend on the user to provide the necessary expertise making the results susceptible to inconsistency and poor practice. Therefore, evacuation models are incomplete and oversimplified they do not account for actual occupant behavior during buildings fires. The solution to this problem is to generate theory on human behavior during evacuation from building fires. The social scientific literature can be gleaned to develop these theories, which can then be incorporated into the current evacuation models to accurately simulate occupant behavior during fire evacuations. These models can then achieve more realistic results from which buildings are designed. The purpose of this paper is to reevaluate our current egress modeling techniques and advocate for the inclusion of a comprehensive conceptual model of occupant behavior during building fires. The paper begins by describing the current state of evacuation modeling of human behavior in fires and identifying gaps in current behavioral techniques. The second part of the paper outlines a general process model for occupant response to physical and social cues in a building fire event.