Daylighting performance assessment of traditional skywell dwellings: A case study in Fujian, China

Abstract

China's rural revitalization strategy has aroused people's attention toward the preservation and renewal of traditional dwellings. Characterized by small courtyards and small top openings, traditional skywell dwellings in southern China are facing prominent daylight environment problems. However, only few studies have evaluated the visual comfort in skywell dwellings under daylight conditions using incomprehensive methods. To fill this gap, this paper systematically assessed the daylighting performance of skywell dwellings in Xingxian Village from 2D reference planes and 3D spatial interfaces. An accurate daylighting simulation model of skywell dwellings was established and validated with field measurements. ClimateStudio was used to analyze the performance metrics from the aspects of daylight quantity, daylight uniformity, and glare. Results identify insufficient daylight quantity indoors as the severest problem in skywell dwellings, which require artificial lighting throughout almost the entire daytime. Seasonal glare and inferior daylight uniformity were also observed in semi-outdoor areas. The effects of top, horizontal, and vertical spatial interfaces on the daylight environment were further investigated, and results highlight the influence of roof slope and opening setting on indoor lighting, the decay mechanism of daylight quantity on horizontal substrate interfaces, and the mismatch between daylight distribution and the positions of doors and windows on vertical enclosure interfaces. The changes in building orientation and seasons were also found to have limited effects on daylighting performance. These results can guide architects specializing in dwelling renovation, so as to improve the visual comfort of buildings and save up on living and energy costs due to artificial lighting.