This study focuses on natural cross-ventilation improvements in terms of internal air velocity, measured in meter per second in the living room space in Malaysia, using two types of perforated windows namely, Mashrabiya window as well as perforated Malay carving window element to determine the performance of their internal air velocity. Cross ventilation has been proposed as one of the most effective natural ventilation methods for thermal comfort by several studies. It is, however, one of the most misunderstood aspects of passive design's approach to regulating interior temperature. In this study, the proposed design solution is by introducing the Mashrabiya (W1) and perforated Malay carving window (W2) as two predominant indigenous solutions for traditional houses that can be further developed and utilized in modern houses. The research involves three stages. The first stage includes the inventory exercise on five (5) different reference case studies of perforated windows. This is to ascertain the most fundamental and common pattern, as well as the dimensions of each W1 and W2. The second step involves computer simulations utilising Computational Fluid Dynamics (CFD) software known as Ansys fluent R2 2021. This program is used to simulate and evaluate natural air velocity and its performance in an interior context, and to determine the viability of a recommended design solution. Finally, an empirical method is used to predict the internal air velocity. The result shows that W1 and W2 represent effective passive design strategies for energy saving. The air velocity using W1 is three times higher than the normal speed which is 4.5/1.5 m/s, while using W2 makes the air velocity two times higher than the actual air speed which is 3/1.5 m/s. The simulation test and results are discussed based on the Malaysian region with a 1.5m/s wind speed. Understanding the different effects of the size of the voids and the placement of the patterns are significant to improve the indoor natural ventilation performance in a living room space.