HEALTHCARE this are relatively simple, and the associated solutions can be rudimentary in luminaire and engineering terms. Typically, there is a requirement for an average and maximum lux level, a glare rating and, finally, a colour-rendering target that almost all types of modern lamps can satisfy and exceed. In some areas, there may also be a luminaire hygiene requirement or impact rating but, again, these criteria are easily achievable. Moreover, all are easily measured and checked. This means that a standard or agreed set of criteria can be designed to and delivered, such that a contract can be easily assessed as having been completed. By comparison, while a patient has visual needs for example, to read, get dressed, bathe, and so on there is also a requirement to create a relaxed environment to reduce anxiety and stress. Rather than satisfying a numerical medical need, this relaxed environment requires a very different approach to the lighting and interior design. Views of nature and access to daylight have been shown to improve recovery, and there is a general preference for natural light over electric light. The difficulty with this non-visual (or emotional and biological) need is that the solutions are more involved and it is more difficult if not impossible in some cases to demonstrate that the design and delivery will reduce anxiety or improve recovery. Whether a design and installation have created a relaxed environment could be subjective and, therefore, difficult to place into a contract. However, we are now lighting in an age when the wealth of information about Chase Farm Hospital, Enfield | NON-VISUAL LIGHTING the benefits of non-visual light means we can no longer ignore those aspects. We need to find a way to address both the numerical solution and subjective design. When not undertaking medical procedures, the staff also need a lit environment that is relaxing, homely and supports their shift patterns. What is particularly difficult here is that not everyone will have the same shift patterns; those arriving to work in the early evening are starting their day when some and, in particular, the patients are at the end of their day. When you consider the shift patterns alone, you have to question if it is even possible to take them into account. Perhaps, where the staff and patients share the same spaces, the patients needs must come first to maintain their circadian rhythms. Where the staff predominantly occupy spaces, then their needs and circadian rhythms are given precedence. Another group to add to the already congested list is that of visitors. These people are, or at least should be, healthy, so the lighting does not need to cater to improving their recovery, for example. Their daily light cycle is likely to be in line with daylight, so they will have similar non-visual needs to the patients. What is important for the visitors is to enter a space that makes them feel good and that gives them some privacy with their friend or family member. When visitors experience the right type of environment, they are relaxed, which is conducive to a better bedside manner; this, in turn, helps improve the recovery of the patient. The typical medical numerical solution does not provide such warmth and personal feeling. The final group of people who require lighting to do more than just satisfy a numerical, medical set of criteria is the estates team. They want the lighting to achieve all of the above, but they also have to maintain and manage the lighting www.cibsejournal.com December 2019 9 CIBSE Dec19 pp08-10 Healthcare lighting Supp.indd 9 22/11/2019 14:52