The Permanent Supplementary Artificial Lighting of Interiors

Since the opening of the half-century, new ideas on building have been visible everywhere. These visible changes are the expression of a revolution in building construction methods and in the economic picture of building. Rising costs demand a more efficient use to be made of available space, which in turn means deeper rooms with lower ceilings. Daylight is not free, it must be paid for in terms of cubic feet of space, square feet of glass, and loss of heat. In fact the provision of adequate daylight to the back of a deep room in the quantity now considered adequate by modern standards would lead to such an amount of glazing that not only would the cost be prohibitive, but the discomfort from sky glare would be unacceptable. It is shown that permanent supplementary lighting can be used to overcome these difficulties. The cost of installing, running and maintaining such lighting is offset by the reduced costs of building and maintenance and by a more efficient use of the available site. Experimental studies have been made to determine the levels of supplementary lighting that are necessary for a good integration of daylight and artificial light. The results of these studies are applied to a new technical college and to an agricultural research laboratory.