The results show that the wind at the inlets of the reference house in case 1 had an average velocity of 0.4 m1s. However, the average velocity was reduced to 0.2 m1s in case 2. This seems contradictory to the previous study [12], which showed that a rectangular building has better natural ventilation than a square building. However, the houses in this study had very small lots. When located on the same land lots, the houses with rectangular shapes had more space at the front and the back than the houses with the square shapes. The distance between the two houses became very small, which blocked the wind from passing through. Therefore, houses with square shapes (case 1) will give a higher air velocity at the apertures than houses with rectangular shapes (case 2). Thus, case 1 is more appropriate for natural ventilation.