Nowhere is the absence of sensory experience more vivid than in modern buildings that minimize contact with anything natural - whether it is air, daylight, views, green vegetation, materials, patterns, or color. Our modern workplaces are seas of bland cubicles that isolate rather than integrate people - not unlike the cages in the old style zoos.

Fortunately, the old style cages are disappearing in favor of more naturalistic habitats in an effort to improve the psychological and behavioral well being of animals. Is there a lesson for us here? Can we enhance human psychological and behavioral experience by revolutionizing building design? By increasing contact with natural processes and by incorporating nature into buildings? By reducing the use of hazardous materials and chemicals? By saying people matter? If we were to think this way, we would look at buildings as an employee benefit - not just as a way to house an organization.

At its core, green building philosophy aims to provide this transformation, and, in doing so, to enhance human well being and performance in work settings. However, the evidence for these positive impacts is slim, due in part to the lack of a compelling conceptual framework for measuring human outcomes and linking them to design features.

There is some evidence of reduced absenteeism and increased productivity in green buildings, but little understanding of the links between design features and human outcomes. Of particular interest to many is the potential impact of sustainable building design on worker productivity. However, there is little explanation of how productivity benefits might accrue, beyond reduced absenteeism associated with reduced illness (especially Sick Building Syndrome and Building Related Illness). A more comprehensive view of health and well being begins to suggest additional indicators that fall broadly under the topic of "human resource sustainability".1 Figure 1 illustrates this integrated view of well being.

Medical models of health integrate behavioral, social, psychological, and mental processes. So, too, should building models of health and well being. At the present time, however, much of the green building literature focuses on air quality and physical health, thereby ignoring the other dimensions that are equally important. Ironically, many of the prominent features of green buildings are likely to have their greatest impact on cognitive and psycho-social well being. For instance, contact with nature and sunlight penetration has been found to enhance emotional functioning. Positive emotions, in turn, are associated with creativity and cognitive "flow," a state of high task engagement. Other green building features, such as indoor and outdoor relaxation areas with vegetation and views, are likely to enhance social interactions and sense of belonging - both of which are associated with organizational attachment, a topic of enormous interest among organizations today.

Drawing on research from a variety of studies in the US and Europe, it is possible to more fully identify links between these well being outcomes and building features, as shown in Figure 2. As can be seen, several design features affect more than one dimension of well being. Personal control over ambient conditions, temperatures, ventilation, and materials selection affects both physical and neuro-cognitive well being, including performance outcomes. For instance, research by David Wyon has found consistent connections between temperatures, ventilation, air quality and performance on cognitive tasks requiring high levels of focus attention.2 Each of the links shown in the figure has been identified in at least one field or laboratory study.3 However, most of these studies have been conducted in traditional buildings, and often in buildings with serious health problems associated with high levels of reported illness symptoms or discomforts.

Until recently, there was no evidence that proved green buildings led to the well being of its occupants.

Testing the Theory

The links between worker well being and the building features of a green building were tested in a case study of the Miller SQA building in Holland, MI.4 Miller SQA, a wholly owned subsidiary of Herman Miller, Inc., remanufactures Herman Miller office furniture.

The overall goal of the study was to develop a conceptual framework and methodology for assessing the benefits of green buildings.5 Designed by William McDonough + Partners out of Charlotteville, VA, the 290,000-square-foot building houses a manufacturing plant and office/showroom. The building houses approximately 700 people (600 in the manufacturing plant across three shifts, and 100 in the office). It contains a fitness center with a full-length basketball court, exercise machines adjacent to windows that overlook the countryside landscape, and convenient break areas.

Key green building features in the new building include good energy efficiency, indoor air quality, and daylighting. The site includes a restored wetlands and prairie landscape.

Prior to its move into the new green facility in 1996, Miller SQA was housed in a smaller industrial type building several miles away. The old building was also divided into manufacturing and office areas. The building had ribbon windows lining the perimeter walls in both the manufacturing and office areas.

The Results Productivity and Quality

Studies have shown that most organizations take weeks to months to regain lost efficiency associated with moving. However, the Total Quality Metrics data that Herman Miller uses to evaluate its overall performance showed an overall increase in productivity of 0.22% in the nine-month period after their move. On-time delivery also increased from 98.54% to 99.53%, and product quality increased from 98.97% to 99.23%. The increases are small because there is relatively little room for improvement - an indicator of Herman Miller's overall high level of near perfect operation. In addition, while the increase is small, it is possible that the pattern would change with a longer period of study. Nine months is probably an insufficient time period to capture long-term productivity benefits.

Notably, however, there was no productivity "dip" with the move to the new facility. In contrast, a pre- and post-occupancy study of the West Bend Mutual Insurance Company found a 32% drop in median productivity of the office workers when they moved.6 Although Herman Miller SQA and West Bend Mutual are two very different companies, the temporary dip experienced by West Bend is more typical of moves to new buildings.

Further, the new facility accommodated a growth in manufacturing plant staff. Again, it is notable that there was no "dip" in productivity despite new staff needing to acclimate. In the old building, the plant staff worked more overtime to complete the work.

The only Total Quality Metrics performance measure that showed a significant decrease in the year following the move to the new building was the decrease in performance bonuses for the workers. Funds that would normally go into worker bonuses were going instead to help pay for the new building. This was a temporary condition that was expected by the workers. However, given that bonus pay is a significant performance motivator, it is worth noting that work output remained high, despite the rather significant loss to workers' total income. It would not have been surprising to see a dip in the organizational measures associated with reduced effort or motivation.

Increased Motivation for Daytime Manufacturing Workers

Three key indicators of motivation and emotional well being increased for daytime manufacturing workers in the new building. These workers indicated that in terms of "looking forward to work," being "in good spirits at work," and being "excited about work," overall, they were happier in the new building. Over 20% expressed an increased sense of being in good spirits while at work.

Prior to the move to the new building and again nine months after the building was occupied, workers were asked to complete extensive surveys. Figure 3 compares the pre-/post-occupancy survey outcomes for the daytime manufacturing workers. As can be seen, there was a positive change on all measures, except fatigue at the end of the day, which showed a slight increase. Interestingly, however, fatigue during work showed a modest decrease.

When asked to directly compare the old and new facilities on a number of well being outcomes, the daytime workers rated the new building as more positive for all measures. There was a 60% increase in workers' "overall feeling about the environment," and over 30% said the new building was better for social well being, as indicated by increases in ratings of sense of belonging and overall work spirit. Job satisfaction was also higher in the new building, as were self-ratings of work performance. (See Figure 4.)

Direct comparisons of environmental features in the new and old buildings show a similar pattern, with daytime workers rating the new building as better across a range of features. The data in Figure 5 show the percentage of workers in each shift that rated the new building as better than the old one. A significant 80% of daytime workers rated temperatures and daylight as better in the new building, and 60% perceived the new building as healthier. Over 40% rated contact with nature, electric light and air quality as better. Almost 30% also rated control over the environment as better - an important factor in psychological and physical comfort.

Interestingly, there were strong differences in perceptions and experiences across the three manufacturing shifts, with daytime workers in general more satisfied with the building than those in the second shift and night shift. The data presented here focused on the daytime workers only. An extensive discussion of the differences between the manufacturing shifts appears in HPAC Magazine, November 1998.

Improved Work Performance for Office Workers

Office workers rated the new building more positively overall than the combined shifts of manufacturing workers. However, there were fewer differences in the well being measures for office workers pre- and post-occupancy. For instance, there were no differences on ratings of feeling excited about work, looking forward to work, and being in good spirits at work. There were, however, increases in ratings of fatigue, both during work and at the end of the day. This is likely to be due to an increased workload, as shown in the increased ratings of "feeling overworked" in the new building. In the old building, only 12% of the office workers said they often or always felt overworked, compared to 33% in the new building.

The fact that they felt overworked but still had high ratings on the well being measures may indicate a buffering effect of the building environment. Although we cannot verify this conjecture, it is entirely consistent with research on the negative effects of feeling overworked. Work stress has been found to have a negative impact on motivation and emotional functioning, but that was not the case for the SQA office workers.7

There was also a large increase in the percentage of office workers who said they looked forward to working in the building. In the old building, 45% said they looked forward to working in the building, while 70% responded this way for the new building - an increase of 25%.

In direct comparisons of the old and new buildings, office workers perceived the new building more positively for a number of well being outcomes. As shown in Figure 6, the most positive ratings were for perceived healthiness of the building and overall feelings about the environment. Furthermore, 40% or more said the new building was better for their work performance, privacy, and overall work spirit. Workers also rated the social environment as better, with 37% saying the new building was better for relationships with coworkers and 28% saying the sense of belonging was better.

It is worth noting, however, that 40% or more of the workers said there was no difference between the buildings on these outcomes. Although we cannot say for certain why there is such a large percent that did not experience a difference between the two work settings, it is possible that the interior spatial variability may be a factor. Office workers do not have equal access to daylight, views (either internal or external), and other building amenities. Those in interior spaces with high cubicle partitions essentially work in windowless offices without daylight. And if they worked under the same conditions in the old building, it is hardly surprising that they would perceive the environment as unchanged. Unfortunately, we were not able to gather locational data due to the need to keep survey responses confidential. However, other work for a California office building plotted survey responses on floor plans using a Geographical Information System application. This technique clearly illustrated the spatial effects of environmental satisfaction. Those in the most interior partitioned spaces were the least satisfied with all design features. Similar results were found in a study of seven energy efficient buildings in the Pacific Northwest.8

As seen in Figure 7, ratings of building design features show that over 90% of the office workers said daylight and windows were better in the new SQA building, and more than 50% said air quality, contact with nature, electric light, and temperatures were also better. Only acou-stics stands out as being more negative. This is largely due to the increased openness between the manufacturing plant and office area.

Summary and Conclusions

The real appeal of green buildings lies in their potential to create better building habitats, and to do so by incorporating design features that address health and well being in an integrated manner.

How does the SQA building fare, overall, as a human habitat? Has it created a more pleasing, more supportive space?

The answer is yes - at least for the daytime workers. There is overwhelming evidence that office workers and daytime manufacturing workers perceived the new building as more positive across design features. The fact that workers in the 2nd and night shifts had less positive ratings across almost all dimensions lends further support to the human value of increased daylight, views, fresh air, and contact with nature.

Furthermore, there is strong evidence that the enhanced habitability is associated with increases in psychological and social well being. The effects were particularly evident for the daytime manufacturing workers for whom the environment changed the most dramatically. The impact for the office workers was weaker, but, as noted above, this may have been due to an increased workload. Nonetheless, the fact that there was no decrease in psycho-social well being suggests that the building may have buffered the stress normally associated with increased work pressures. Furthermore, on measures less likely to be affected by increased workload (e.g., sense of belonging, overall work spirit), the outcomes were more positive.

The SQA building clearly lends credence to the "green building hypothesis." The hypothesis states that green buildings are better for people because they generate higher quality, healthier, more habitable spaces than comparable standard-practice buildings. However, one building cannot prove the hypothesis. It is merely one case study. The evaluation of green buildings should become more common until a convincing case can be made. To this end, the City of Seattle is implementing "human factors commissioning" of all its new and renovated municipal buildings that will be designed to meet or exceed the LEEDT Silver level. Other cities and organizations should join Seattle in establishing a comparative database from which all will benefit in the future.