In order to study the orientation and ratio, this investigation used computational fluid dynamics (CFD) software [13] to determine airflow through a given site plan. The study considered two site plans. Houses in case 1 (Fig. 5a) are 9m x 9 m square. Hn case 2 (Fig. 5b), the houses are rectangular, with a 1:1.7 ratio between the sides. Each floor is 7m x 12 m. in both cases, each house has two stories. The CFD analysis used a wind speed of 1.4 m/s from the SSW, which is the most critical wind, as described in Section 3. However, most of the winter winds come from the NNE. Despite their different orientations, the prevailing winds from the two directions can be simulated as one case, since they come from the exact opposite directions and the site plan is symmetric.