This research investigates the influence of vernacular architectural elements on indoor thermal comfort in traditional Malaysian masjids, by focusing on their adaptation to contemporary religious architecture. The study categorizes these elements into eight key façade design strategies, including building form and architectural layout, orientation, height, façade openings for natural lighting and ventilation, serambi, façade shading devices, ventilation panels, and building materials and construction technology. The first research objective identifies serambi as the most significant façade design strategy for enhancing modern Malaysian masjids' thermal comfort. Through a combination of field measurements, questionnaire surveys, and computational simulations, the study establishes a strong correlation between serambi design and passive cooling performance. The second research objective further substantiates the relationship between the serambi opening-to-wall ratio (OWR) and indoor thermal comfort. The findings indicate that variations in OWR directly impact air circulation efficiency, temperature regulation, and humidity control, thereby influencing the overall comfort levels within prayer halls. Computational Fluid Dynamics (CFD) simulations and empirical data confirm that excessively high OWR values (>80%) lead to increased solar heat gain and glare, whereas low OWR values (<30%) restrict ventilation and result in stagnant indoor air conditions. Based on these findings, the third research objective formulates design recommendations to optimize serambi OWR for enhanced thermal performance in contemporary masjids. The study concludes that a serambi OWR range of 60%–70% achieves the optimal balance between ventilation efficiency, air exchange rates, and passive cooling effectiveness. These recommendations provide an evidence-based framework for sustainable masjid design, ensuring that future religious spaces integrate vernacular architectural principles while addressing modern climatic challenges.