This paper describes a Calibration methodology which is specifically configured to best match actual building performance, based on a case study conducted to calibrate whole building energy model using Building Energy Management System (BEMS) measured data. It details the calibration approach which was designed to meet the specific characteristic of the spaces, systems and energy use in the pilot school building. Two calibration methods were developed; one is for electrical and the other is for thermal energy along with calibrated weather file. The result shows excellent correlation with the measured electricity and room air temperature and demonstrates the effectiveness of the methodology. Mean Bias Error (MBE) and Cumulative Variation of Root Mean Squared Error (CVRMSE) for electricity consumption is 6% and 14% respectively and -5 and 7% for air temperature.