Effectiveness of daylighting design and occupant visual satisfaction in a LEED Gold laboratory building

Using daylight as primary light source has been widely recognized as an important strategy to reduce building energy demand and enhance indoor environment quality. However, to design and operate a building to make full use of daylight, which is a dynamic light source, to meet diverse occupant needs remains a challenge. This paper reports a post-occupancy study of the visual environment in a laboratory building on a university campus, and puts a spotlight on the building occupants as it examines the effectiveness of the daylighting design and systems integration in creating a visual environment to support occupant comfort and satisfaction while reducing artificial lighting demand. Results show generally high satisfaction with daylit work environment and positive effect of the horizontal shading strategy. Issues about the integration between daylighting and electric lighting systems and level of occupant control are identified and discussed for improving the effectiveness of daylighting and enhancing the quality of the visual environment in the building of study. A multiple-tool methodology is developed and tested, which included occupant surveys, interviews, illuminance measurements, continuous data loggers, fisheye-lens camera and glare-identifying software, and documentation of spatial settings, systems features, and user behavior.