In the Illuminating Engineering Society’s Forum for Illumination Research, Engineering, and Science, designer and educator Christopher (“Kit”) Cuttle, MA, PhD, FCIBSE, FIESANZ, FIESNA, FSLL, proposed a new approach to lighting design that integrates illumination factors beyond workplane light levels.
The problem with existing technique, he says, is:
Lighting practitioners are poorly served by the illumination metrics that are currently used to specify, measure and predict lighting in buildings. Almost a century has passed since the Lumen Method was introduced, providing a simple tool for enabling a prescribed average illuminance to be provided over the horizontal working plane (HWP). What is truly remarkable is that, to this day, the concepts upon which it is based persist as the basis for specifying illumination levels in lighting standards.
As professional understanding of lighting’s impact developed in the mid twentieth century, this resulted in a segmentation in design between practitioners either engineering workplane light levels or using artistry to go beyond to address lighting’s other impacts:
The lighting profession is now divided between practitioners who use illumination metrics to achieve reliable and efficient compliance with lighting standards, and those who apply lighting to influence the appearance of people’s surroundings and who shun the use of illumination metrics, which they see as inhibiting their creativity and their scope to “think outside the box.”
The answer, Cuttle says, is to combine these approaches into a single set of best practices supported by metrics:
It is proposed here that there is scope for an innovative procedure that combines components from both sides of this division. Lighting’s role in influencing the appearance of people’s surroundings provides a sensible basis for determining the overall illumination quantity to be provided, where surroundings is taken to include all visible surfaces and objects within the space. The appearance of details, which may include anything that deserves attention (including visual tasks), may be crucially affected by illumination distribution within the space, and managing illumination quantity and distribution within an enclosed space calls for competent application of illumination metrics. Application of such a procedure should support the achievement of any set of lighting design objectives without inhibiting innovative design options – as the imposition of the uniformity criterion does.
Check out the specific of Cuttle’s argument and the solutions he proposes here.
