BASICS 8 of 19

When you light up a room the light bouncing around the room plays a major role in illumination. It takes a larger number of fixtures and lamps to light up a room with dark walls and carpeting than one with white walls and light carpeting.

Many lighting designers work in layers of light. First they fill the room with ambient or general lighting. Then, they provide task lighting—desk lamps, undercabinet lighting—for those areas which need more light. Finally they decorate the walls or perimeter with accent lighting.

While lighting levels are usually measured on horizontal surfaces, it is important to get light on vertical surfaces (like walls). It gives an impression of brightness. Vertical illumination is also important in supermarkets and warehouses so labels can be read.

If more efficient lamps are used, the same light level can be attained for lower energy costs OR higher light levels can be obtained for the same energy cost.