1. Introduction
Lighting is one of the largest energy consumers in buildings [1]
and accounts for 5–15% of the total electric energy consumption [2].
In this context, daylighting strategies have been studied and proposed
in order to reduce artificial lighting energy demands [3–7].
Lighting controls in connection to daylighting can save lighting
energy demands by 20–40% [6].
Occupant behaviour is a crucial factor in determining lighting
energy use in buildings [8]. Lindelof and Morel [9] investigated light
switching patterns during working hours and showed lighting are
on although daylight is enough to provide adequate illumination.
Based on previous studies, this paper aims to reveal occupancy
patterns, actual lighting use patterns and their effects on lighting
energy demands. Results from a field survey, which was conducted
from February to June 2010, are presented. The paper describes
the hourly profiles of lighting use patterns over 24 h of day and
discusses lighting energy saving potentials by the utilization of
daylight.