Revisiting the national standard of daylighting in Indonesia: A study of five daylit spaces in Bandung

The current Indonesian national standard on daylighting in buildings (SNI 03-2396-2001) proposes a number of criteria to design and evaluate daylighting condition in indoor spaces, where some of the criteria are unique to other national standards. To assess whether there is correlation between the standard and the subjective perception of the building occupants, student assessments were conducted, by using 30 engineering physics bachelor students, in five daylit spaces in the campus of Institut Teknologi Bandung in Bandung, Indonesia, during overcast days. The students were asked to draw a boundary line between daylit and non-daylit area in the given room. The results were compared to the Indonesian national standard, window-head-height rule of thumb, and contour lines yielded from simulation using Radiance/Daysim which indicated the daylight autonomy, useful daylight illuminance, and daylight factor. It is found that the fully and partially daylit areas according to the students are mostly in accordance with the areas covered with the lines of 1/3 room-depth and 1.5 window-height. The full and partial daylight boundary lines according to the students mostly overlap with daylight factor contour lines of respectively 0.4-1% and 0.3-0.7%. The 50% daylight autonomy with target illuminance of 300 lx and 500 lx respectively correspond to the student's fully and partially daylit areas. Lower criteria of both static and dynamic metrics, compared to current standard and rules, might be applied to indicate indoor daylight availability in Bandung.