Abstract
A method is outlined for predicting the likely use of manually operated lighting. The method is based upon patterns of switching behaviour observed in field studies. A series of worked examples are given which demonstrate application of the method to multi-person offices and open-plan teaching spaces. Two points of interest revealed by the examples are the considerable effect that a midday switch-off has on the predicted overall time that lights are on in a space; and the comparatively small effect that gradual afternoon switch-on of lights has on overall use.