Daylight and health impacts of residential opening designs

Abstract

Human health is affected in a wide range of ways by adequate exposure to daylight, especially in residential buildings. There is evidence that insufficient daylight disturbs circadian rhythms, resulting in an increased risk of illness among certain groups of the population. Although Indonesia is a tropical country with abundant sunlight, various studies indicate that 60-90% of its population suffers from vitamin D deficiency. Specifically, this study aims to explore optimal daylighting for residential buildings situated in Yogyakarta, Indonesia. This article discusses the design and calculation of windows and skylights using Horizontal Shading Angle (HSA) calculations and Vertical Shading Angle (VSA) calculations in accordance with local climate conditions. To determine the best design, VELUX daylight simulation should be used, followed by a comparison with Indonesian national lighting standards, SNI 6197:2020. The findings recommend a maximum skylight size of 3.9 m2 and a maximum window opening size of 0.93 m2 to guarantee sufficient daylight penetration throughout the interior spaces (Daylight Factor < 2%). Furthermore, the research highlights an innovative shading design as a means of enhancing glare-free daylight inside the living space.