Honeybrains Cafe in New York. Magda Biernat/Ketra.
Until relatively recently, indoor lighting has been considered a purely functional aspect of our workaday environment. For decades, in otherwise dim commercial spaces, the default approach to illumination was simple: install rows of track lights in offices or, in common retail stores, hang linear fixtures with raw fluorescent bulbs burning overhead. But lighting a space with the elemental purpose of merely seeing surface areas is no longer an option when considering the health and well-being of occupants.
Although we have come a long way from scriveners toiling by flickering candles during winter months or even from the days when Le Corbusier could state: “The history of architecture is the history of the struggle for light,” the refinement of light for significant improvements in health is an ongoing process.
Along with progress in acoustic technology, indoor air quality, and environmental enhancement concepts such as biophilic design, light is an important, if underestimated, aspect of architectural strategies focusing on wellness. Building occupants are not only affected physically by light but they are also affected psychologically. Gloomy spaces illuminated by harsh sources—halogen and fluorescent bulbs, for example, or even LED lights, which have drawn complaints about “dirty electricity” and migraines—are bound to affect occupants who, after all, spend dozens of hours a week in workspaces. Prolonged exposure to blue light—commonly found in bulbs, computer monitors, and smartphone screens—can negatively affect the release of melatonin, a hormone that regulates sleep, boosts the immune system, and retains antioxidant properties. Combining these everyday blue light sources with poorly designed lighting can wreak havoc on biological systems.
While the design industry develops tunable white-lighting technology (adjusted via smartphones) and experiments with horizontal sources, the sun remains the gold standard for well-being vis-a-vis light. Natural light not only helps the body absorb Vitamin D, but it also regulates the circadian system, also known as the biological clock, and aids in the production of serotonin, a neurotransmitter hormone whose levels can play a role in depression. Depleted serotonin levels can influence moods and emotions as well as cause sleep difficulties. Because serotonin helps produce melatonin, maximizing natural light for overall health is imperative.
Recent studies have shown that a steady dose of natural light can increase energy, improve moods, and sharpen cognitive function—results that underscore how important designing with the occupant in mind has become.
Other negative outcomes from a lack of natural light include Seasonal Affective Disorder, migraines from bare fluorescent bulbs, and a disruption of the circadian rhythm. Circadian rhythms are the physical and emotional responses to the 24-hour cycle. When most people think of circadian rhythms, they usually think of sleep, and how disrupting the body clock can lead to insomnia, fitful sleeping patterns, and subsequent fatigue or lethargy. But the circadian rhythm impacts far more than just sleep; it also affects metabolism, the immune system, blood sugar levels, and mental health.
In 2002, the ASHRAE Journal reported on a study that reflects one of the most intriguing benefits of natural light: cognitive improvement. “Students in classrooms with the most window area or daylighting were found to have 7% to 18% higher scores on the standardized tests than those with the least window area or daylighting,” read the report. Studies have also shown that cortisol—known as “the stress hormone”—rises in a dimly lit environment, such as a cubicle in a typical office.
For patients in hospitals, circadian lighting can have positive physiological effects. ZGF Architects recently designed a behavioral unit center in Seattle, Washington, with circadian lighting, that has shown tangible positive results.
Providence Health & Services, Swedish Medical Center-Ballard, Behaviroal Health Unit. ZGF Architects LLP.
Still, even natural light in a workspace is often inadequate to avoid negative impacts. Some of the byproducts of direct sunlight in an office environment, such as uncomfortable temperature, monitor glare, and overwhelming brightness at peak hours, make it difficult to rely completely on solar. And rainy days, overcast skies, and the winter months also limit natural light. So do some sustainability pursuits. “Due to restrictive energy codes, daytime light levels in buildings are often too low or at threshold for activating the circadian system,” Mariana Figueiro, the director of the Lighting Research Center at Rensselaer Polytechnic Institute, told Architect magazine. “Even in open offices with many, large windows, workers do not receive enough daylight to stimulate their circadian system, due to factors such as season, cloud cover, desk orientation, and window shade position.”
Because environmental cues are what regulate circadian rhythms, it makes sense, health-wise, to design surroundings in keeping with the 24-hour cycle. To that end, architects are not only planning spaces with an emphasis on natural light, but they are also experimenting with circadian-attuned technology, programming indoor light sources to mimic the natural processes of the 24-hour cycle. This process stresses cool and bright light (blue) in the morning and, as the hours pass, gradually dims into warmer hues, giving the body an approximation of the natural light cycle. Even a café in New York City, Honeybrains, has adopted circadian lighting for “happier vibes.”
Just as architecture changed its outlook on light in response to modern aesthetic and technological advances—cooling systems meant less reliance on proximity to windows and larger spaces created greater floor depths—it must now become responsive to the demands of biological and behavioral imperatives by maximizing natural sources essential to humanity.