Strategies to achieve optimum visual quality for maximum occupant satisfaction: Field study findings in office buildings

For visual quality, the traditional focus on illuminance for paper-based tasks and brightness contrast for visual acuity is becoming less relevant in modern offices with backlit computer screens and sporadic use of paper. This research aims to investigate critical correlations between user satisfaction, workstation lighting conditions, and the physical attributes of the work area. The statistical analyses were conducted to identify applicable recommendations leading to improved visual quality in today's work environment while maintaining optimal user satisfaction. Findings from post-occupancy evaluation on 1,232 workstations in 64 office buildings revealed that satisfaction level would increase by 20% on average when the occupants have a view to the outside in their seated workstations. Upgrading the ceiling light fixture with an indirect lens type increases visual satisfaction. Workstations with an indirect lens type had higher satisfaction (62%), while a prismatic ceiling lens type showed the lowest user satisfaction (34%). The analysis further identified that a combination of indirect light fixtures with task lights increases user satisfaction by 21%. Lastly, utilizing window shading devices revealed greater satisfaction with glare management. The occupants with external and internal shading devices in their work areas showed the highest satisfaction with their overall lighting. In addition to the recommendations mentioned above, an illuminance level of 406 lux for the work surface achieves maximum satisfaction in contemporary office environments.