LIGHTING | MANIFESTO FOR CHANGE The ambient lighting manifesto Leading lighting academics Peter Boyce, Kit Cuttle, Kevin Kelly and Peter Raynham are calling for a fundamental change to lighting practice P rogress in society, science and technology often depends on a paradigm shift and we believe one is needed in the way interior lighting is generally practised. By this we mean designers must stop designing lighting to deliver a specified uniform illuminance on a horizontal working plane and, instead, give priority to lighting the space rather than just focusing on the visual tasks. There are four reasons for this belief: Today, a lot of the information necessary to perform a task is delivered through self-luminous screens, so task illumination is not required. The number of tasks that require visibility of fine detail is much reduced, partly because of the availability of good-quality photocopying and printing, and partly because of the growth in machine vision, computer power and robotics. Light generates visual and non-visual responses important for human health and wellbeing. This is directing attention away from lighting the task to light received at the eye. Lighting that delivers a set illuminance on a hypothetical horizontal working plane is irrelevant to what should be the main functions of lighting: making the whole space visible and supporting human health Continuing to define good lighting by nominal task illuminance delivered to a horizontal working plane means we will miss a chance to save energy and money. Current practice Lighting is undertaken by a number of groups, ranging from designers, equipment manufacturers, architects and building services engineers to electrical contractors. These have varying levels of expertise and different income streams, so the amount of time spent on lighting design varies but they do have two things in common. They all use software to develop their designs, and they follow illuminance standards produced by national and international bodies. To do otherwise poses a risk of litigation should the client be dissatisfied. 38 December 2020 www.cibsejournal.com CIBSE Dec20 pp38-39 Supp Ambient lighting.indd 38 20/11/2020 16:03