Role of Natural Lighting in Sustainable Building Design

Abstract

Natural lighting, or daylighting, is an important component of sustainable building design because it can reduce dependence on artificial lighting while supporting visual comfort, occupant well-being, and connection with the outdoor environment. Effective daylight design depends on building orientation, window placement, glazing, room depth, shading, skylights, reflective surfaces, and responsive lighting controls. This paper examines the role of natural lighting in sustainable building design, focusing on energy efficiency, visual comfort, indoor environmental quality, occupant health, architectural strategies, glare and overheating, daylight simulation, and implementation challenges. Properly designed daylight can reduce lighting electricity demand and may also reduce internal heat gains associated with artificial lighting. However, excessive daylight can cause glare, visual discomfort, and unwanted solar heat gain, increasing cooling demand in some climates. Sustainable daylighting therefore requires a balance between adequate illumination, thermal performance, glare control, and occupant needs. The paper argues that natural lighting should be considered during early architectural planning rather than added through larger windows without performance analysis. Integrated daylight design, combined with shading, efficient glazing, responsive controls, and appropriate building orientation, can contribute to energy-efficient and healthier buildings.