Studies on daylight design and regulation of high-density residential housing in Hong Kong

Abstract

Around 20 cities in the world have 10 million inhabitants or more. In these cities, buildings are fighting each other for natural light. Finding ways optimize the natural agent without compromising development density is a task for architects and engineers. This paper reports a series of research projects, commissioned by the government of Hong Kong, to understand the problem and to develop a new design and regulatory method for Hong Kong. The study first looked into the issue in terms of existing rules and policy, and identified their shortcomings. It then investigated daylight performance of the existing building stock with on-site measurements. Though a territory-wide user survey, the study proceeded to relate these quantitative data to user satisfaction and requirements. A minimum performance standard based on Vertical Daylight Factor (VDF) on the surface of the window was established. Using theoretical modeling, on-site measurements and computational studies of real and hypothetical cases, a design method based on Unobstructed Vision Area (UVA) was developed. The government of Hong Kong has adopted this performance-based approach; new building regulations are currently undergoing on-site trial.