Architectural design and its impact on daylighting in Gayo highland traditional mosques

Abstract Daylighting in traditional mosques is intricately linked to local architectural design, which responds to the unique climate conditions of the region, creating spaces that balance natural light with the cultural and environmental needs of the community. Traditional mosques in Indonesia reflect indigenous architectural knowledge that adapts to local climates. These mosques often feature designs such as four-sided sloping or pyramid-shaped roofs, a style known as typical Javanese. This study investigates the impact of architectural design on daylighting provision in two traditional and historical mosques in the Gayo Highlands of Aceh: Asal Penampaan Mosque (M1) and Tue Kebayakan Mosque (M2). Despite their similar roof styles, these mosques differ in materials and window designs, affecting their interior illumination levels. The study is conducted through field measurements to measure the existing daylight, and simulation utilizing VELUX Daylight Visualizer to simulate daylight levels (illuminance) and daylight factor (DF) in both mosques. The results show that M2, which has been refurbished with modern materials and larger windows, achieves higher illuminance and DF values compared to M1, which retains its traditional sago palm roof and smaller apertures. The findings suggest that window placement and interior surface reflectance significantly influence daylight availability. The dark surface colour of the natural material, such as the sago palm roof, dominates the interior and provides little reflectance of daylight, thus minimizing its distribution throughout the room.