environments for workers than conventional buildings. Two measures of productivity were used: sick days and the self-reported productivity percentage after moving to a new building. The authors noted that the survey and its results were preliminary.
The survey was conducted in 154 buildings that contained more than 2,000 tenants. Some 534 tenant responses were collected from buildings located across the United States. Miller et al. found that 55 percent of the respondents agreed or strongly agreed that employees in green buildings were more productive, while 45 percent suggested no change (p. 81). They also found that 45 percent of the respondents agreed that workers were taking fewer sick days than before moving to a green building, while 45 percent found it was the same as before and 10 percent reported more sick days (all in ENERGY STAR®-labeled buildings).
Miller et al. also calculated the economic impacts of those tenants who claimed an increase in productivity. Economic impacts were “based on salaries that approach the cost of rent using a very conservative square foot per worker assumption” (p. 81).
A Comparison of the Performance of Sustainable Buildings with Conventional Buildings from the Point of View of the Users
G. Baird, A. Leaman, and J. Thompson. Architectural Science Review 55(2): 135-144. 2012.
Baird et al. sought to determine whether users perceived sustainable buildings to perform differently from conventionally designed buildings. The questionnaire used was the standard two-page questionnaire developed by the Buildings in Use (BIU) study for office buildings. The questionnaire included 45 questions grouped into several categories, including environmental (temperature, noise/acoustics, lighting) and overall satisfaction (design, needs, comfort overall, productivity, and health). The questions typically asked occupants to rate a factor on a scale of 1 to 7, with 1 being unsatisfactory and 7 being ideal.
The set of sustainably designed buildings included 31 commercial and institutional buildings located in 11 different countries. All of the buildings were either recipients of national awards for sustainable design or highly rated in terms of their country’s building sustainability rating tool(s) or had pioneered some aspect of green architecture. The buildings ranged in size from 1,000 to 20,000 square meters and were occupied by 15 to 350 staff. Fifteen of the buildings were predominantly office use, 10 were academic teaching buildings, 4 housed laboratories or research organizations, and 2 contained a combination of light industrial and administrative functions. Surveys were gathered from 2,035 staff members.
The comparison set consisted of 109 conventional buildings selected from the BIU database that had been surveyed during a similar time period as the sustainable buildings. Included were buildings occupied by 15 to 1,100 occupants and office, light industrial, visitor center, and academic activities. The independent t-test was used to determine whether differences between the mean values for the various aspects were statistically significant. Among the authors’ findings were the following: