This study investigates thermal comfort and energy consumption in an educational building located in a warm and humid region of India. A comprehensive approach, combining literature review, questionnaire surveys, and statistical analysis modeling, was employed to identify key factors affecting thermal comfort and to propose energy-efficient retrofitting strategies. Statistical analysis of survey data obtained from Google Form revealed the most influential parameters for thermal comfort by use of Statistical Package for the Social Sciences, while simulation software like DesignBuilder and Climate consultant 6.0, an EnergyPlus-associated software, was used to assess building performance and energy consumption. The findings highlight the critical role of building orientation and the materials used in a building in mitigating heat gain. The study identified five critical parameters affecting thermal comfort in educational buildings: thermal transmittance, wall thickness, building materials, occupant health, and body mass index. The study recommends specific retrofitting options, such as improved insulation, shading devices, and ventilation systems, to enhance thermal comfort and reduce energy consumption. The focus in the study is mostly on application of passive strategies to be implemented while doing modification. The findings contribute to the development of sustainable and thermally comfortable educational buildings in similar climatic conditions.