Fast Company's Co.Design report on a University of Illinois study in which office workers without windows slept 46 minutes less on work nights and scored lower on all eight health-survey dimensions than colleagues with daylight.
Overview
Published on Fast Company's Co.Design channel on August 5, 2014, this short piece by Eric Jaffe reports on a study led by architecture professor Mohamed Boubekri of the University of Illinois with medical collaborators, then forthcoming in the Journal of Clinical Sleep Medicine. The question it tackles is simple: does having a window at work change how well people sleep and how healthy they feel? The article's framing is that daylight at a desk should be treated as a public-health issue rather than a perk of seniority.
Key Findings
- The study compared 22 office workers with daylight at their desks against 27 who sat in windowless spaces or so far from glass that no daylight reached them.
- The windowless group scored lower on all eight dimensions of the SF-36 health questionnaire, with statistically significant deficits on two of them, including vitality.
- They also reported poorer sleep on a standard self-report sleep index.
- To move beyond questionnaires, 21 participants wore wrist actigraphs that log light exposure, movement and sleep. The devices confirmed the windowless workers received less light, moved less during the day, and slept an average of 46 minutes less on work nights.
- Five other actigraphy sleep measures, such as night-time awakenings, also favored the window group, though those differences did not reach significance.
- On days off the gap widened to roughly 8.5 hours of sleep for window workers versus 6.5 for the others, and the window group also got more daylight outside work, a result the researchers could not fully explain.
- For context, the article cites an estimate that commercial buildings without windows are worth about 20% less per square foot, and notes a 1997 paper that tried to label the problem "ill-lighting syndrome."
Why It Matters for Daylighting
Offices are a mild case. Warehouses, fulfillment centers and manufacturing floors are the truly windowless workplaces, where most of the floor sits hundreds of feet from any perimeter glazing and the only way to bring daylight in is through the roof. If a desk 20 feet from a window is enough to shift sleep by three-quarters of an hour, the effect on a workforce spending eight- to twelve-hour shifts under electric light alone is worth taking seriously. Diffusing prismatic skylights can deliver daylight levels across a deep floor plate that no window layout can match.
The study is small, with 49 participants and 21 actigraph wearers, and Jaffe's own comment thread raises the possibility that age differences between the groups explain some of the sleep gap. Treat it as a well-designed pilot that points in the same direction as the larger circadian literature, not as a definitive number.
About the Source
Fast Company is a U.S. business magazine founded in 1995; Co.Design was its design-focused section, and this article carries Co.Design's "Evidence" label. The author, Eric Jaffe, covers cities, history and behavioral science. The library copy is a six-page browser printout of the August 5, 2014 web article, including one reader comment. The article remains live on fastcompany.com, and the underlying paper (Boubekri et al., 2014) is in the Journal of Clinical Sleep Medicine.
This page is an original summary written by Logistics Lighting. The source article is the copyrighted work of its publisher and is referenced here for research and educational purposes under the fair-use provisions of Section 107 of the U.S. Copyright Act. A reference copy of the original is provided for convenience; please contact the publisher for any use beyond fair use.
← Back to the Daylighting Library