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Post-Occupancy Evaluation of the Forrestal Building. January 1993-December 1994.

pdf icon Post-Occupancy Evaluation of the Forrestal Building. January 1993-December 1994. (3565 K)
Sanders, P. A.; Collins, B. L.

NISTIR 5591; 67 p. March 1995.


Department of Energy, Washington, DC

Available from:

National Technical Information Service


building technology; contrast; energy efficiency; environmental assessment; federal relighting; illuminance; lighting; luminance; post-occupancy evaluation; temperature; VDTs; occupant response


A post-occupancy evaluation was performed on the Department of Energy Headquarters Building (the Forrestal Building) in Washington, DC. The lighting in the building was retrofitted with new, more energy-efficient, components to meet energy target guidelines. Occupant responses to the indoor environmental conditions, particularly the lighting, were studied to determine the impact of the relighting on the building inhabitants. In addition, physical measures of the lighting and other environmental conditions before and after the relighting were compared. The post-occupancy evaluation employed a questionnaire about the environmental conditions and physical measures of the space (lighting, space, noise, temperature, etc.) A total of 244/220 people participated (before and after the relighting, respectively). Physical measures were taken at 100 work stations before the relighting and 75 after. Analysis of the physical measurement data indicated generally higher lighting levels with more even distribution of luminances in the offices. Occupant response to the changes in the lighting was generally quite positive. The relighting was perceived to have improved the appearance of the building substantially, as well as the lighting within individual workstations. Finally, guidance is given for doing post-occupancy evaluations as part of other relighting initiatives.