The human body needs natural light to create enzymes and proteins for a healthy life. Without enough natural light, our circadian system gets out of sync and can no longer properly regulate sleep, alertness, and concentration. We become less productive. But too much direct sunlight can lead to glare and heat gain, which can make us less productive.
Did you know window shades play a key role in increasing productivity?
Does natural light really affect one’s work?
As mentioned above, our bodies need natural light to regulate sleep, alertness, and concentration.
A 2019 Building and Environment article made the case how important that is to productivity. “Access to daylight and view in an oﬃce improves cognitive performance and satisfaction and reduces eyestrain: A controlled crossover study,” by Anja Jamrozik, et. al., says this:
- Employees in spaces designed to prioritize daylighting miss less work, are more productive, and make fewer mistakes 
- In a 1998 study of 100 diverse employees in a southern European company, workers in spaces with more daylight penetration were more satisﬁed with their jobs, reported better well-being, and indicated they were less likely to quit their jobs 
- Call center customer service representatives with better views had faster call processing times 
- Oﬃce workers with windows worked more than those without windows 
So natural light—and the means of getting it into a building—should be an essential part of designing a building for maximum productivity.
Why can’t we just use electric lighting?
Having an effective electric lighting system does not replace our need for natural light. A 1994 study  showed there was a statistically significant improvement in job performance in offices with windows.
And there’s more to it than just the light itself. Access to views to the outside provides a connection to nature which has also been found to have an impact on mood, satisfaction, and performance. A 2003 study  showed the mood of daytime workers was significantly better than nighttime workers in the same office with windows.
What happens when we add all those windows?
With the incorporation of more windows into building design there can be some negatives. Glare, solar heat gain, and direct sun on workers’ eyes or workspaces can make it harder to perform basic work functions and lower productivity.
A 2004 study by Helsinki University of Technology/Berkley National Laboratory  found an average decrease in productivity 2% per degree of Celsius when temperature is above 25 degrees C (77 Fahrenheit). Another study by University of Chicago researchers  showed as much as a 4% decrease in productivity per degree Celsius over 27 C (80 F).
A 2003 California energy Commission study  showed the greater the glare from primary view windows, the worse the office worker performance was, decreasing productivity by 15 to 21%.
How much is this really costing?
Let’s imagine a typical office building with 24,300 rentable square feet, which translates into about 20,000 usable square feet. At an average of 175 square feet per employee that’s going to yield approximately 114 employees on that floor.
With an average salary of $40,000 per employee, plus payroll taxes, benefits, training, and other related costs, we reach a total labor cost of $6,384,000 a year. That means every 1% gain in productivity is going to result in a savings of $63,840 annually.
How big a difference can motorized window shades make?
Let’s target a 2% increase in productivity and estimate a return on investment (ROI) for installing motorized shades in our typical office. For the typical floor plate, motorized shades will cost between $58,600 and $72,275 depending on window sizes and layout (we used three ‘typical’ window patterns for this analysis). A simple ROI calculation will put the payback period between 5.5 months and 6.8 months. With an average lease length of 7 years, our typical tenant has realized an increase in productivity of approximately $821K or 11X the initial investment. And 2% is an extremely modest expectation. The California Energy Commission  estimates that excessive glare can reduce productivity by up to 21%.
Featured image: Motorized FlexShade® with custom redirectional channels and Mermet® E Screen fabric. University of Chicago, Gordon Parks Arts Hall. Dealer: Beverly Venetian Blind Co., Monee, Illinois. Photographer: Barry Rustin.
 J.J. Romm, W.D. Browning, Greening the Building and the Bottom Line: Increasing Productivity through Energy-Eﬃcient Design, Rocky Mt. Inst., 1998, p. 16.
 P. Leather, M. Pyrgas, D. Beale, C. Lawrence, Windows in the workplace: sunlight, view, and occupational stress, Environ. Behav. (1998)
 Heschong Mahone Group – California Energy Commission, Windows and Oﬃces: A Study of Oﬃce Worker Performance and the Indoor Environment, (2003)
 M.G. Figueiro, M.S. Rea, A.C. Rea, R.G. Stevens, Daylight and Productivity – A Field Study, ACEEE Summer Study Energy Effic. Build., 2002, pp. 69-78
 A. Hedge, Reactions of computer users to three different lighting systems in windowed and windowless offices, Work and Display Units, 1994, B54-B56.
 Olli Seppanen, William J. Fisk, David Faulkner, Helsinki University of Technology/Berkley National Laboratory, Control of temperature for health and productivity in offices, 2004.
 E. Somanathan, Rohini Somanathan, Anant Sudarshan, and Meenu Tewari, The Impact of Temperature on Productivity and Labor Supply: Evidence from Indian Manufacturing. 2018.