Research so far on the inclusion of occupant behavior into energy simulation has provided with valuable understanding on how occupant behavior impacts building energy use and indoor comfort. However, thermal comfort requirements due to occupant behavioral activity changes (i.e., metabolic rate and clothing insulation value) have not been well blended into the simulation framework. Many of the integration methods are not able to show or connect with real occupant’s activities.This research presents a new framework to include behavioral activity changes into the simulation approach. The energy and comfort results of a simulation-based method to bring occupant behavioral activity into the building control loop are compared with the results of the fixed control schedule simulation. The emphasis is the impact on energy use and indoor comfort levels due to behavioral activities and temperature setpoints adjusted accordingly. Since a variety of behavioral activities take place in a residential setting, this research adopts multi-family apartments for an in-depth case study analysis.This research utilizes the American Time Use Survey (ATUS) for the latest available data on occupant behavioral activities in a residential building. The energy simulation software is embedded with the EnergyPlus dynamic simulation engine. The comfort analysis is determined using the Predicted Mean Vote/Predicted Percentage of Dissatisfied (PMV/PPD) model. The comfort model will include metabolic rate and the clothing insulation values for each activity.The results of this study suggest that the new framework to include occupant’s behavioral activities into the building control loop will not only yield energy savings, but also shows significant improvement in comfort levels. Advisors/Committee Members: Wang, Julian (Committee Chair).