Post-occupancy evaluation of sunshades and balconies' effects on luminous comfort through a questionnaire survey

To protect and improve the built environment, the Hong Kong government recommends sunshades and balconies as two daylighting green features to be incorporated into new buildings. A questionnaire survey was conducted to investigate the effects of these green features on subjective luminous comfort in housing units. The results showed that some practical functions decided the preferences of residents for tilted or horizontal sunshades and balconies with glass walls and parapets. Both features had direct effects on reducing glare and overheating problems, but at the same time, they decreased daylight uniformity. Further, balconies provided poor privacy, which forced residents to use internal shading and artificial lighting more often. Based on the analysis, green features affected residents' luminous comfort indirectly by unconsciously affecting their feelings and behavior. Practical application: These results may help the government to understand the status quo and establish appropriate guidelines and help researchers and architects improve green features that provide residents with better luminous environments. The data can be used for further studies that adopt the climate-based simulation to present the real luminous condition of the units whose residents were involved in this survey. The luminous comfort could then be quantified by some cumulative metrics, and those metrics can be treated as the standard for the energy-efficient building design.