A building envelope has a significant influence on the overall energy consumption of a building. Presently, Building Information Modelling (BIM) and Building Performance Simulation (BPS) tools are advanced and cost-efficient options for analyzing and improving the energy-efficient building envelop. However, existing BIM-BPS-based studies incorporate several buildings envelop parameters that account for static occupancy profiles. This contributes to higher discrepancies between the actual and simulated energy consumption. Also there is a dearth of studies about the hospital and restaurant building envelop by considering the local construction materials. Thus,the key aim of this study is to perform a stochastic occupant-centric building energy assessment for hospital and restaurant building envelop using agent based modelling (ABM) and BIM-BPS tools. Initially, stochastic occupancy, HVAC and lighting ON/OFF profiles were generated using a robust ABM-BIM approach followed by the real-time data gathering for verifications and energy model construction. Afterwards, the building energy performance was evaluated using the BPS tools, while initial energy consumption data was calibrated using the pre-installed smart meter data in Chittagong, Bangladesh. The study also empowers the assessments of CO reduction, carbon credits, life cycle, and payback time analysis from the sustainable built environment perspective. The findings show the highest amount of monthly energy-saving for the hospital (Case 3) and restaurant (Case 3) buildings around 37.42 % (July) and 32.52 % (October), respectively, while considering the local envelop materials. Moreover, the maximum amount of CO reduction was 17.71 tons/year and 12.31 tons/year, and the equivalent earned carbon credits were 88,539.5 BDT/year and 61,524.1 BDT/year for hospital and restaurant buildings respectively. Additionally, the study calculates the payback period for both buildings by considering different local envelop materials. The findings of this study have presented a new framework between ABM, BIM and BPS based building envelop simulation, and contribute to proper building envelop material selection in low-income cultural contexts. Lastly, the study has provided areas for further studies such as the need for a comprehensive model construction process, seasonal occupancy patterns, climatic factors, and composite materials study for different envelop systems which serves as limitations of this current study.