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 1232 workstations in 64 office buildings revealed that satisfaction level would increase by 20% on average when the occupants have seated view to the outside in their work area. Upgrading the ceiling light fixture with the indirect lens type could increase visual satisfaction. In particular, workstations with the indirect lens type had higher satisfaction (62%), while the prismatic ceiling lens type showed the lowest user satisfaction (34%). The analysis further identified that a combination of indirect light fixtures with task lights could increase user satisfaction by 21%. Lastly, utilizing window shading devices revealed greater satisfaction with glare management. The occupants who have external and internal shading devices in their work areas showed the highest satisfaction with their overall lighting. In addition to the recommendations mentioned above, the illuminance level identified to achieve maximum satisfaction is 406 lux for the work surface in contemporary office environments.