Research in workplace design shows that having a windowed office does more than signal status, it also means you're getting a better night's rest - and with rest comes productivity.

A growing body of research shows that getting enough sleep speeds your decision-making and learning ability, while sleep deprivation does the opposite. Did you know the human body’s highest alertness is at 10:00 a.m. and it’s fastest reaction time is at 3:30 p.m.? However, most people are still refilling their coffee mug, fighting to stay awake in the boardroom or napping in their secret hiding spot due to irregularities in their circadian rhythm.

According to Northwestern researcher Ivy Cheung, working next to a window by day could have a profound effect on your night. But most people work in an office that looks like this:

In a pilot study presented last June at the annual SLEEP meeting, Cheung and her colleagues tracked the behavior and light exposure of 49 day-shift office workers. Of these, 27 worked in windowless workplaces and 22 worked in workspaces with windows.

“Compared to the group with no windows, workers with windows in the workplace had 173% more white light exposure during the workday and slept an average of 47 minutes more per night,” Cheung and her colleagues wrote.

While the study is preliminary and only found a correlation between sleep and natural light exposure during the day, the findings seem to make sense.

Bright white light from the sun provides a signal to our bodies, cuing our cycles of sleep and wakefulness. If you don’t get enough sunlight, studies suggest, your body won’t have the same cues that it needs to get ready for bed.

This is also why using your smartphone before bed is a bad idea. The bright, blue-colored light sparks your brain’s wake-up cycle right when it should be shutting down.

While being starved of natural light is more of a problem for workers crammed into the windowless open office than for managers lounging in the well-lit corner suite, the insight has impacts on management. Research shows that sleep-deprived people aren’t just irritable; they have a tougher time remembering things and take stupider risks.

Circadian rhythms can influence sleep-wake cycles, hormone release, body temperature and other important bodily functions. They have been linked to various sleep disorders, such as insomnia. Abnormal circadian rhythms have also been associated with obesity, diabetes, depression, bipolar disorder and seasonal affective disorder. The diagram below shows body functions of a well calibrated circadian system.

Cheung and her colleagues outlined a few options to getting around the problem. For one, they say offices should be designed to provide more windows to workers. But, if you can’t knock down any walls, a much cheaper option could be investing in LED skylights, which mimic outdoor daylight conditions and create an illusion of nature on your ceiling.

By: Mark Jenzen