Skylight parameters that affect lighting, cooling, heating, fan, andstotal energy use in office buildings are examined using the state-of-the-art building energy analysis computer code, DOE-2.1B. The lightingseffects of skylight spatial distribution, skylight area, skylight visiblestransmission, well factor, illumination setpoint, interior partitions,sceiling height, and glazing characteristics are discussed. Thissstudy serves as the foundation for the creation of a DOE-2.1B databasesand design tools for estimating daylighting energy savings fromsskylights.