This study utilized BIM technology (eQUEST) to conduct an energy consumption analysis and simulated re-design of the Civil Engineering Research Building at National Taiwan University. After obtaining a verifiably accurate simulation, energy-saving effects were investigated by altering the building's envelop design and analyzing the results. In addition, cost remains a crucial factor throughout the process in order to reflect the relationship between building expenses and energy efficiency during design scheme optimization. The results of this study can provide better and more comprehensive choices for building owners, designers, and developers in future. (C) 2016 Elsevier B.V. All rights reserved.