Lighting control systems deliver the correct amount of light at the right time and right place. Lights can automatically turn on, off or dim at set times or under set conditions. Facilities managers can make changes to lighting when appropriate or to meet financial incentives, and users can have control over their own lighting levels to provide optimal working conditions. Lighting control helps to reduce costs and conserve energy by turning off (or dimming) lights when they are not required. Energy savings resulting from daylight harvesting mean not only low electric lighting and reduced peak electrical demands, but also reduction in the load on the air conditioner. On the other hand thermal and visual comforts play a very important role regarding the satisfaction of occupants with their working environments. The most effective method to achieve thermal comfort in offices is to reduce cooling loads in order to avoid additional energy-consuming devices for cooling. Most daylight responsive lighting control systems save energy by reducing lamps output in proportion to the amount of available daylight while maintaining a given illuminance level on the working plane. In this paper, variation of room illuminance with daylight along with variation in room temperature is studied. It is proposed to reduce the total electrical load in a general office.