Indoor lighting standards and their role in lighting practice

Indoor lighting standards were first introduced as a means to ensure the efficient performance of visual tasks in workplaces. Their scope soon expanded to cover a wider range of applications as well as visual discomfort. They thus became a means to eliminate bad lighting, and in this they have been successful. However, now they are often seen as a restriction on the freedom of lighting practitioners to develop alternative designs. This is partly because standards have been issued for applications where there are no critical visual tasks, and partly because the conventional design procedure ensuring compliance with standards assumes a regular array of luminaires. Three steps are proposed for overcoming this problem. The first is to separate lighting recommendations into standards and guidance. Standards should be legally enforceable and devoted to eliminating bad lighting. Promotion of good lighting should be achieved by applications-specific guidance documents. The second is to change the metric used in standards from task illuminance to ambient illuminance, from lighting the task to lighting the space. The third is to change the design method used from the lumen method to the lighting design objectives procedure.