This research originated from an interest in developing products with a holistic and interdisciplinary systems engineering approach, toward fostering sustainability. A comprehensive method which helps designers make better decisions in the earliest design stage was applied for conceptual model development and comparison. The study developed a new-design passive house with a double-skin envelope that delivers better energy consumption performance for heating and cooling relative to a conventional reference house, while achieving comfort-level indoor temperatures. A single-fa?ade reference house was designed with the identical geometry, material and conditions of the new house living quarters, in order to demonstrate the new house performance using a valid comparison. The new house and reference house were simulated cases and were not calibrated by actual models. The energy simulations demonstrated that the heating and cooling demands of the new house were 19.1％ and 18.8％ lower than those of the reference house, respectively. Furthermore, fluid dynamics behavior of the air inside the double-skin envelope was analyzed to demonstrate the airflow’s contribution to the energy performance. Computational fluid dynamics simulations revealed that turbulent airflow in the underground space on summer day increased heat transfer, and laminar airflow in the double-skin roof on winter night decreased such transfer.