Preferred luminous conditions in open-plan offices: research and practice recommendations

This paper compares research participants' choices of office lighting with recommended practice and existing research, and concludes with practical recommendations for lighting installations. Participants were given the opportunity to choose lighting conditions for VDT office work as part of an experiment concerning the effects of individual control over lighting on task performance and satisfaction. Most participants' choices bettered current energy code specifications for lighting energy use, while largely following both CIBSE- and IESNA-recomrnended practice for desktop illuminance. Average luminance ratios between the VDT n and background were lower than recommended practice but consistent with those in other investigations. No effects of age or sex were observed. Farticzpants who made lighting choices at the end of the day-long session chose conditions that created less VDT-screen glare from reflected images, as compared with those who chose lighting conditions at the start of the day. Despite a high degree of variability in the chosen luminous conditions, overall ratings of lighting quality and environmental satisfaction were high.