Healthy office lighting is important.
As health trends continue to permeate the office and our working environment, one area not given much attention is lighting. Clearly we love what lights do to create an atmosphere. Although office design trends today tend toward open spaces with more aesthetic natural lighting, artificial lighting is a necessity in an office. If you can’t use 100% natural light, let’s at least make sure it’s healthy office lighting.
Lets quickly review some of the fundamentals of healthy lighting.
Most people think in terms of brightness, however, there are other factors to consider in addition to brightness.
Brightness. This important quality of lighting is measured in lumens. A 60-watt incandescent bulb has a brightness of 800 lumens.
Color Temperature. The second piece is color temperature measured in Kelvin: 2000K – 3000K is warm light which is cozy and inviting; 3100K – 4500K is cool white light which is bright and vibrant; and 4600K – 6500K is more like sunlight/daylight and is invigorating. By adding more blue light, this number can increase beyond 6500K.
Color Rendering Index. The final component is Color Rendering Index (CRI) and means the lights ability reveal the color spectrum in the same way natural light does. The higher the number, the fuller the spectrum and these numbers range from 1-100.
Natural light is best…
As we all know, offering as much natural light as possible in an office is best. In fact, a study published in Health Environments Research and Design Journal reported nurses exposed to natural lighting experienced lower blood pressure, better moods, increased alertness and better cognitive performance. And, a study conducted in Britain showed that windows were the number one determinant of worker satisfaction with the building.
Of course we know that abundant natural light is not always possible in an office environment, so what to do? The next best thing is to utilize lighting components to “simulate” natural lighting. Combining color temperature of 5000K or more and a CRI of between 80 and 90 is how this simulated natural lighting is generally accomplished.
Information also shows that adding blue to light can increase work performance, support mental acuity, and create a happier more productive employee. A UNC article says adding blue to lighting creates great brainstorming areas whereas warmer tones might be best for areas in an office like conference rooms and break rooms.
And finally, how much brightness is optimal?
Brightness is often a personal preference in workspaces. But a general rule of thumb is to ensure there is at least 215 lux at 30” above the finished floor, which is generally desk height. If you start there, it’s a good foundation for making any other smaller adjustments for the differences in personal taste or the requirements of specific tasks.
Clearly, lighting can impact employee health and productivity.
That being said, any improvements in your workforce are going to make a difference. We like to think of it in terms of the 3/30/300 Rule. If you spend $3 per square foot on utilities, you will spend $30 per square foot on facilities and $300 per square foot on the people in the building. Without a doubt, spending money on your employees is the biggest bang for your buck. And healthy office lighting is a hinge between your utilities, your facilities and your people.