THE ILLUMINATION of our workplaces affects occupants much more than we credit, says Simon Thorp of LAPD Lighting Design.
Low levels of daylight and prolonged exposure to uniform artificial light are linked with depression, anxiety, insomnia and even osteoporosis.
It stands to reason, then, that natural and artificial light are important factors in staff morale and productivity. Getting it wrong could lead to increased absenteeism, so it’s vital to design office lighting with employee wellbeing in mind to ensure the company can get the best out of its team.
We evolved to spend our days outside, where constantly-changing levels of daylight can reach around a hundred thousand lux.
The advent of electric lighting created a shift towards spending much more time indoors where daylight is typically replaced by a constant light level of 300-500 lux more comparable to an overcast day than the sharp shadows created by the sun. The physical and mental impact on workers who can easily spend 40% of their waking hours in the office is therefore clear.
The quality of daylight has benefits over artificial lighting; its colour temperature changes throughout the day, starting with warmer light in the morning, cooler light in the middle of the day and warm again towards sunset. These changes facilitate the function of our circadian rhythm.
Moreover, daylight has a full spectral distribution which includes non-visible wavelengths of light that help us remain alert. In comparison, most forms of artificial lighting are deficient in large chunks of the spectrum. This is why office workers should have views to the outside world wherever possible, but daylight needs to be controlled to eliminate glare, particularly on computer screens, and solar gain needs to be limited to maintain a comfortable environment.
Artificial lighting needs to work in combination with natural light during the day, as well as provide the sole light source after dark, so the distribution of artificial light is crucial. The optimum arrangement is indirect light on the ceiling and walls, local task lighting to provide high light levels where needed and lower level lighting including uplighting, focal points and other features elsewhere.
The colour temperature and spectral distributions of LED light sources influence the mood and alertness of office workers.
Thanks to the wide range of LED lighting available today, daylight equivalent spectrums are now achievable, along with various distributions between this and a warmer 3,000K light source. It’s also possible to vary the colour temperature throughout the day to emulate the changing colour temperature of daylight.
Good lighting, designed in accordance with the WELL Building Standard (https://standard.wellcertified.com/light), coupled with well thought out interior office design can assist drastically in improving mood, reducing illness and absenteeism and creating a healthy environment in the workplace.
- Simon Thorp is director of LAPD Lighting Design
- Learn more about best-practice lighting for offices at the Workplace and Wellbeing Conference, taking place at the LuxLive 2019 exhibition at London ExCeL on Wednesday 13 November and Thursday 14 November 2019. Entry is free – see the full programme and register for free HERE.