A 2008 study by the Leonardo Academy measured operating costs for 11 buildings certified under the LEED-Existing Buildings (EB) program, each of which had a significant component of office space (Leonardo Academy, 2008). Operating costs included cleaning expenses, repair and maintenance expenses, roads/grounds expenses, security expenses, and administrative and utility expenses. Data for the LEED-EB-certified buildings were collected and compared to the operating costs in BOMA’s (Building Owners and Managers Association) Experience Exchange Report, an industry standard. The authors found that “in all categories of operating costs, more than 50% of the LEED-EB buildings have expenses less than the BOMA average for the region. Total expenses per square foot of the LEED-EB buildings are less than the BOMA average for 7 of the 11 buildings” (p. 21).

Fowler and Rauch (2008) calculated aggregate operating costs for 12 GSA green buildings and compared those costs to industry baselines. The baselines were developed from a number of sources, including data from BOMA and the International Facility Management Association (IFMA). Aggregate operating costs included water and energy utilities, general maintenance, grounds maintenance, waste and recycling, and janitorial costs. They found that, on average, aggregate operating costs were 13 percent lower than average costs than the industry baselines. However, several of the buildings had consistently higher operating costs in each category.

Fowler et al. (2010) analyzed operating costs for 22 GSA green buildings using the same definition of operating cost as Fowler and Rauch (2008). Fowler et al. found that, on average, aggregate operating costs were 19 percent lower for the green buildings than the baseline. Aggregate operating costs for 17 of the buildings were 2 to 53 percent lower than the industry baselines. Five of the 22 buildings had higher aggregate operating costs than the baselines, ranging from 1 to 27 percent higher.


The committee identified five studies that met its criteria for time frame, robustness, and relevancy, and that compared IEQ and the health and productivity of workers in high-performance or green buildings to that of workers in conventional buildings.5 It should be noted that a body of well-designed, empirical studies evaluating various factors related to IEQ in all buildings is available. However, in keeping with its narrow focus on the statement of task, the committee evaluated only studies specifically related to IEQ and high-performance or green buildings.

Abbaszadeh et al. (2006) looked at the satisfaction of occupants in green buildings compared to the satisfaction of occupants in conventional buildings, using information from the CBE database. They compared surveys from occupants in 21 green buildings (15 were LEED-certified and 6 additional buildings were reported as green, based on the receipt of national or local green building or energy efficiency awards) to CBE surveys from occupants in conventional buildings.

The study focused on occupant satisfaction with thermal comfort, air quality, lighting, and acoustics. The authors noted that “self-reported productivity scores follow the same pattern as those of satisfaction—productivity scores are high where satisfaction is high and low where satisfaction scores are low” (Abbaszadeh et al., 2006, p. 366). Other findings included the following:

  • On average, occupants in LEED-certified green buildings were more satisfied than occupants of conventional buildings when it came to thermal comfort, air quality, and overall satisfaction with workspace and building.
  • The mean satisfaction score in LEED-rated/green buildings was significantly higher than that for conventional buildings (1.47 versus 0.93).


5 Three additional studies, Birkenfeld et al. (2011), Singh et al. (2009), and Cook (2005), analyzed only one or two buildings each, and for that reason were not included in the review of studies by the committee.

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