Energy-conscious design of school buildings can contribute to significant energy savings and improve the students' learning environment. The purpose of this research is to formulate design recommendations for school buildings in the hot-humid climatic zone and assess the influence of different design variables on their energy consumption. A base-case classroom was constructed by taking commonly used values for each design variable. Using computer simulation techniques, these variables were modified one by one to find the value that minimized energy consumption, while keeping thermal and visual comfort in the room. Based on these tests, the recommended value for each design variable to achieve a high performance classroom, was determined. Comparative tests were done to determine which variables have greatest impact on the energy consumption and thermal comfort in the classroom, and how their absolute influence depends on the order of implementation of each improvement. A complex interdependence among the design variables was found, but strong conclusions for energy savings could still be reached. (C) 2008 Elsevier Ltd. All rights reserved.