Insight | Thinking about Lighting and Biophilic Design. Part 2/2

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Biophilic design aims to support our innate tendency to seek a connection with nature. In lighting design terms this can include contributing to suitable conditions for interior landscaping and internal planting, through to a full ‘human-centric’ lighting approach. This two-part essay explores some of our thinking on this topic, balancing support for the aims of biophilia with environmental responsibility and the benefits of keeping things simple.

Part 2: How ‘Natural’ is Electric Light?

Another increasingly popular area of biophilic design concerns designing electric lighting that better supports our natural circadian rhythms. In practice, this has manifested as attempts to replicate ‘natural lighting conditions’ through regulating light intensities and colour temperatures. Limited by current technology, this approach tends to overlook some of the essential qualities of daylight. Outdoor lighting levels can typically vary from 100,000 lux during a spell of bright sunshine down to less than 2,000 lux on an overcast day. Naturally lit interiors follow a similar ratio, depending on fenestration. These levels of light are impractical and unsustainable to create artificially. Other characteristics of natural light are also challenging to replicate, for example, the continual dynamic shifts in intensity caused by the relative movement of the sun and clouds.

Natural light comes in many forms, the two most obvious ones being the difference between direct sunlight and indirect diffused light. The play of sunlight can bring shadow play and brilliance – but it can also create glare and solar gain. Diffused light minimises shadow, but it can make things appear flat and dull.

While it is possible to emulate some of these characteristics artificially, our experience is that balancing available natural light with the skilful supplementary use of artificial light creates the best response. After dark - which can be during a typical working day in winter - artificial 'daylight techniques' often make a space feel unnatural. Creating an appealing evening and night-time character and atmosphere requires a different creative approach.  

And then there is a further often overlooked factor to consider: of all the artificial light sources we are exposed to, the light from the screens of our computers and devices has arguably the most impact on us. Yet, this 'screen light' is rarely included in the design of human-centric lighting systems, particularly in the workplace.

So, rather than focusing on high-level singular human-centric lighting 'solution', we believe the simpler options for improving the wellness of interior space with light are still the best. Research has shown that allowing people some level of personal control, such as localised lighting that they can adjust in terms of colours and levels to suit their mood and preferences, positively impacts their wellbeing. Even the act of encouraging people to go for a walk outside at lunchtime would go a long way to improving conditions for wellness.

Views out are another vital aspect. It is a long-held tenet of architectural design that windows have two visual functions. The first is to control the ingress of natural light. The second is to provide a connection to the outside world. Quite often, in open-plan spaces, there is competition for a seat near a window. Depending on orientation, this can be both a blessing and a curse. High levels of daylight, glare and heat can be problematic, particularly when working on screen-based activities. Conversely, being too far from natural light and relying entirely on artificial lighting for visual tasks is proven to be sub-optimal. A good solution would be to include flexible spaces with good visual connections to the outside world and plenty of natural light as collaborative, social or break-out places where people can gather, work casually or chill.

As a practice, designing for wellbeing is a central part to our ethos. We remain open-minded and curious about new developments in the role artificial light can play in this, and we are looking forward to seeing a lot more research and investment into approaches that are properly thought through, well-designed and ultimately sustainable.