Office windows can improve sleep and overall health, study suggests

Windows in offices can help workers sleep better and live healthier lives, according to a study co-authored by Dr. Mohamed Boubekri, associate professor in architecture.

Results showed that workers who had office windows and exposure to daylight slept an average of 46 minutes more every night than those without windows, and they also experienced better quality of sleep. Workers in darker offices experienced lower vitality, social functioning and mental health. Additionally, workers in offices with windows received 173 percent more white light exposure during work hours.

Boubekri collaborated with researchers from Northwestern’s department of neurology and the Hwa Hsia Institute of Technology’s department of architecture in Taiwan.

The researchers performed an experiment that compared 22 employees who worked in offices with windows to 27 employees who worked in workplaces without windows or exposure to daylight. All participants in the experiment worked from 8 a.m. to 5 p.m. A subset of 21 participants (10 workers in windowless environments, and 11 in workplaces with windows) wore wristbands that measured light exposure, activity and sleep-wake patterns.

“Workers are a group at risk because they are typically indoors, often without access to natural or even artificial bright light for the entire day,” Ivy N. Cheung, a Ph.D candidate who works under co-author Phyllis Zee in Northwestern’s Interdepartmental Neuroscience program, wrote in an email. “Office hours occur at a time of day where light exposure has strong impacts.”

Although the study’s findings align with the experimenters’ original hypothesis, Boubekri said that the results are groundbreaking because research about the impact of architecture on light exposure and health is relatively scarce.

“Researchers were doing work in the area of light and health, but they did not link it to architecture,” he said. 

Moreover, Boubekri wanted to investigate the specific relationship between architecture and lighting and health, specifically focusing on the workplace.

“Doctors usually don’t link the workplace environment to health issues necessarily,” he said. “People have to work and have to be indoors from eight to five, and I wanted to know the implication of that situation on people’s health.”

Apart from better health and quality of sleep among workers in lighter offices, Boubekri said, the researchers also found a significant increase in levels of physical activity with those who had office windows.

“The only way to explain it was that maybe (workers in dark offices) were either depressed or fatigued and were not in a mood to go outside,” he said. “That’s probably the only plausible explanation.”

For those in windowless offices, Cheung suggests periodic breaks to “get outside for light exposure during work hours.”

“Taking a walk during a break or enjoying lunch outdoors are easy ways to increase daytime natural light exposure,” she said.

As a result of this study, Boubekri and the researchers suggest that architects should place more emphasis on incorporating windows in the workplace to promote better health and well-being among workers. More specifically, Boubekri recommends placing workstations no more than 20 to 25 feet from walls with windows. 

Apart from quality of sleep and health, the study also raised “possible ramifications” in terms of looking at the Vitamin D deficiency that results from the lack of sunlight exposure, he added. 

“Vitamin D deficiency could be a reason for cancer, and some people believe it has to do with the lack of sunlight,” he said. “So when you put buildings into that equation, what does architecture do? It’s not just the climate where we live, but what kind of architecture facilities hinder our exposure to sunlight.”

Because this was a pilot study, Boubekri said, he hopes to explore this topic more deeply in future projects.

The study was supported by the Illinois Campus Research Board of the University and grants from the National Institutes of Health. It was published in the Journal of Clinical Sleep Medicine in June.


Stephanie can be reached at [email protected]