I just read an article about the correlation between green buildings and fewer workplace sick days in Business Week. I definitely think it makes sense, as many green buildings have better air quality. The article states, "Respondents reported an average of 2.88 fewer sick days in their current green office versus their previous non-green office. About 55% of respondents indicated that employee productivity had improved. Based on the average tenant salary, an office space of 250 square feet per worker and 250 workdays a year, the decrease in sick days translated into a net impact of nearly $5.00 per square foot per year. The increase in productivity translated into a net impact of about $20 per square foot. The study also showed that green buildings have 3.5% lower vacancy rates and 13% higher rental rates than the market." The rest of the article can be read here: http://www.businessweek.com/the_thread/hotproperty/arch
ives/2009/11/green_buildings.html

Does this sound accurate? I would assume that it would be attributed to indoor air quality--but I may be missing something? Or could it simply be that the employees in many green buildings lead healthier lifestyles, in general?

Actually, there is something called SBS, or sick building syndrome, when a building's toxins or lack of ventilation can cause acute health and comfort effects. It's been a problem deemed by the World Health Organization since the 1980's, when it estimated that 30% of new buildings could cause sicknesses. This can be caused by chemical toxins, mold, bad lighting or ventilation, contamination, and so on, which contibutes to a myriad of building-related sicknesses.

On the other hand, I agree with you that SBS doesn't seem to explain all of it. This study was only an observation of a trend of companies that have moved from older to newer workplaces. Maybe it's just that people enjoy working in new buildings, or that the new building is roomier and more practical to work in. Another possibility is that when a growing company is able to replace an old building with a new sustainable building, it's probably at a higher income, and better able to offer its workers healthcare benefits and other morale-boosting perks.

It also makes sense, without considering SBS, that green buildings have a 3.5% lower vacancy rate. One of the guiding decisions of when a business goes bankrupt is whether the money it gains during a good business season will compenate for the loss during the bad business season, namely, utility bills and other repairs. Sustainable buildings are generally newer and easier to repair. Plus, more efficient buildings need to pay less for water, electricity, or other check-ups. Adding all those factors to the fact that sustainable buildings are quite trendy, it doesn't surprise me in the least that they should generate 13% higher rental rates than the market.

I think that lighting plays a role in this as well. Artificial lights have been linked to increased headache frequency, elevated blood pressure, and sleep disorders. I speak from experience, having been diagnosed with Circadian Rhythm Disorder. This is basically a form of insomnia which results from a confusion in my biological rhythms: my body thinks it is night when it is actually day. Thankfully, there is a simple solution, and that is exposure to natural light early in the morning and avoidance of excessively bright, artificial light late at night. It has made all the difference!

Most commercial lighting standards come from groups who have a vested interest in selling more lights, so of course they will diminish the value of natural light whenever possible. However, with the negative effects of artificial light well-established, it follows that a building designed to allow more natural light to enter will have healthier employees.

Well the term "green buildings" often related to a building being LEED EB certified and if that is what you mean then you and the others whom replied are all correct. LEED covers a broad array of categories from indoor air qulity IAQ, lighting, energy, recycling, and many other green items. Worker productivity is like a holy grail as far as measuring it; to me there are no real metrics for it that everyone can agree on but in general if a building is LEED EB certified there is a higher probability that it will have an improved building environment that people can percieve. If the temperature is stable, the air quality is good, and the space has good lighting then people will naturally feel better about being there and feel healthier.