A study of opinion in offices with and without user controlled lighting

,!This paper describes a survey of user attitudes toward control systems and the luminous conditions they produce in 14 similar UK office buildings—seven sites with user controlled general lighting and seven sites without. The installations without user control had better conditions when judged in terms of conventional recommendations for task illuminance, and luminance ratios and levels. User opinion in installations with user control were more satisfied with planar illuminance and had more positive attitudes toward control, whilst other aspects relating to lighting quality were assessed similarly in the two types of installation. Given that the controllable systems were typically operated at 50% of maximum output it appears these systems offer considerable scope for energy saving without compromising occupants’ perceived lighting quality.