Exploring the optimal Window Wall ratio is essential for rural and traditional buildings in Malawi to achieve adequate and resilient housing for the rural communities. Thermal comfort is crucial in providing sufficient housing and sustainable indoor environments for human development and existence. Two traditional dwellings at Katola Village in Rural Lilongwe District were selected to be assessed, and simulation studies were conducted to achieve optimum Window Wall ratio design for traditional houses in Lilongwe, Malawi. A building model was developed to simulate the optimal Window to Wall ratio, and 18 building orientation variations were assessed at 20° increments from 0° to 340°. Additionally, the Window to Wall ratio range selected was from 10% to 90%, while 0% and 100% were eliminated as extreme ratios. Three primary criteria for each Window to Wall ratio and building orientation assessment were used: air temperature, air velocity, and daylight factor. A mean score was developed using international building codes to evaluate how the three criteria impacted indoor thermal comfort for each building orientation and Window Wall ratio. The intersection point of the three criteria was used to determine the optimal Window Wall Ratio for the model building. For accuracy of study data, field measurements and simulation data were correlated for cross-validation for this study. A previous survey of Malawi addresses optimizing an urban dwelling house, but very few studies have been done on traditional housing. The results show that the optimal Window Wall Ratio is between 30% to 50%, and the optimal building orientations for the South are Southeast (160°) and Northwest (340°) for North directions.