The COPE (cost-effective open plan environments) project investigates the effect of open-plan office design on the indoor environment and on the occupant satisfaction with that environment. COPE is sponsored by a consortium of North American public and private-sector organizations and relies on field, laboratory and simulation studies to address designaspects like acoustics, lighting quality, indoor air quality, operating costs and energy efficiency. This paper describes the influence of various design variables on the daylight availability and electric lighting requirements in open plan office spaces using the RADIANCE-based annual daylight simulation method DAYSIM. To make simulation results more reliable a manual and an automated blind control strategy have been considered. Five climatic centers which represent the ambient daylight conditions of 186 North American Metropolitan Areas have been identified. For these five climatic centers over 1000 officesettings have been investigated which feature varying external shading situations, glazing types, facade orientations ceiling designs and partition arrangements. The daylight performance of the offices was expressed in terms of their daylight autonomy distributions and energy savings for an ideally dimmed lighting system. The simulation results reveal, that the daylight availability in peripheral offices allowsfor electric lighting energy savings between 25% and 60% for an ideally commissioned, dimmed lighting system depending on the underlying blind control strategy. 2 nd row offices receive considerably less daylight even though a reduced partition height and increased ceiling reflectances can double electric lighting energy savings up to 40%.

Conference Proceedings of the 2002 Summer Study of the American Commission for an Energy Efficient Environment (ACE): 18 August 2002, Pacific Grove, CA., U.S.A.