This study examines the Energy-Saving Performance Contract (ESPC) of an office building by applying IPMVP Option D in combination with the energy analysis model established for the building by eQUEST simulation software to calibrate energy consumption simulation results using actual electricity billing data. The rates of error between actual values and energy consumption simulation results from the calibrated and uncalibrated models are then explored to confirm the accuracy of the calibrated model. Finally, the calibrated model is used to examine the impact of energy consumption parameter changes on the overall energy consumption in a building. The results indicate that, compared to actual energy consumption, the mean bias error (MBE) and root mean square error (RMSE) for uncalibrated simulation results are 24.48% and 125,050, whereas the MBE and RMSE for calibrated simulation is 0.37% and 34,197. When lighting power density increases or decreases by 50%, overall energy consumption decreases by 30.78% or increases by 31.19%, respectively. Therefore, illumination density has the greatest impact on energy consumption. This study also recommends that accurate parameter settings be confirmed when using IPMVP Option D simulation verification to ensure a highly accurate building energy consumption model, thereby facilitating the Measurement and Verification (M&V) of energy savings. (c) 2013 Elsevier B.V. All rights reserved.