GENERAL

The manner in which a space is illuminated has a noted effect on its use and character. Even in ordinary architecture, advanced lighting methods as clerestory windows, occupancy sensors, return-air troffers, daylight harvesters, and skylights containing translucent insulation can pay for themselves quickly in terms of increased productivity, enhanced occupant morale, and lower life cycle costs. Good lighting can also make a space look larger; thus it is further economical in terms of the illusory area it seemingly adds to a space. Good lighting is also efficient, calms the psyche, and enhances the architecture without bringing attention to itself.

Although illumination design centers around computing lighting loads, this work involves very much more. This was well-described by a leading illumination authority, Louis Erhardt, when he said:

Lighting does more than illuminate "to make visible." It sets the appropriate adaptation, adds to clarity or creates illusion, and leads the eye and the mind to the scene's salient features in an orderly, composed fashion. The purpose of lighting is to achieve the desired atmosphere and inspire a response, mental or emotional, in keeping with the space and the activity. ^{[ ]}

Due to the complexities involved in lighting design, when employing any rule of thumb it is wise to remember the ancient maxim of Alexander the Younger: All generalizations are dangerous, even this one.