The daylighting performance of a suspended particle device (SPD) switchable glazing has been evaluated using an unfurnished outdoor south facing test cell with glazing to wall ratio of 1:8. Interior illuminance levels were determined using useful daylight illuminance level (UDI) for clear sunny, intermittent cloudy and overcast cloudy days. Daylight provided by an SPD and a same area of double glazing were compared. Daylight glare indexes (DGI(N)) and daylight factor (DF) were calculated for SPD "opaque" and "transparent" states. An electrically actuated suspended particle device switchable glazing with transparency that varied between 5% and 55% was found to control daylight glare. (C) 2016 Elsevier Ltd. All rights reserved.