The development of visible sky area as an alternative daylight assessment method for high-rise buildings in high-density urban environments.

This research aims to develop a new daylight assessment method for high-rise residential buildings located in high-density urban environments. The new visible sky area (VSA) method was developed based on data gathered from an extensive survey of high-rise residential building plans and layouts in Hong Kong and followed by a large number of daylight simulation experiments. The results of simulations showed a very small daylight quantity arriving at windowpane of lower floor level of high-rise residential buildings due to high-obstruction from nearby buildings and also self-obstruction. The new method would guarantee the availability of sky area seen from windowpane in order to provide a good vertical daylight factor (VDF), which has been adopted as a performance-based daylight indicator in Hong Kong. A minimum VSA of 12% and 6% for habitable rooms and kitchens, respectively, is proposed for this situation. [ABSTRACT FROM PUBLISHER]