Building orientation is one of the driving factors that impacts building energy consumption, which deserves to be studied. The Sizhai traditional dwellings located in Zhejiang province were chosen as the study buildings in this paper. The geometric model was rotated at 20 degrees increments clockwise to create a total of 18 test scenarios. Integration of virtual simulation in software, the thermal and daylighting performances in 18 test scenarios were simulated to assess their indoor comfort levels in terms of the indoor temperature, air velocity and illuminance. Furthermore, the indoor comfort level has an impact on the energy consumption of building. To this end, the electricity consumption of air conditioner (AC), electrical ventilation and artificial lighting, as well as the total annual electricity consumption including AC, electrical ventilation and artificial lighting were computed by software to explore the optimum Building Azimuth (BA). The results show that a total annual electricity cost difference of approximately 150 kWh throughout a year between the best (S) and worst (Nd-W80) BA of the building was achieved. By performing BA measurement for all dwellings in Sizhai village, the conclusion is that this village has a high energy saving potential. (C) 2019 Elsevier Ltd. All rights reserved.