of high-performance or green buildings to conventional buildings varied, as did the factors evaluated, the methodologies used, and the locations of buildings. None of the studies focused on the long-term cost-effectiveness attributable to the use of building standards or green building certification systems.
Because there is not yet a significant body of objective, research-based evidence available on the topic of the performance of high-performance or green buildings, the committee’s evaluation of the literature review was not straightforward. The green building movement is a relatively recent phenomenon, and so the lack of a standard research protocol, variations in definitions and baselines, limited sample sizes, and the inclusion of many building types were not unexpected. Development of a body of empirical research for any building-related topic takes many years: it typically takes at least 5 years to program, design, and construct a building, which will then be operated for 30 years or longer. Over decades of use, a building’s performance will change as building systems age, through wear and tear, and through changes in occupancy and equipment. How much performance changes depends on the quality of the design and construction, operation and maintenance practices, climate zones, and other factors.
For these reasons and others, as outlined in Chapters 1 through 4, the committee relied on the “preponderance” of evidence from the literature review, its evaluation of the DOD consultant’s report, and its members’ own experience and expertise in developing its findings and recommended approaches, which are presented below.
Finding 1. The committee did not identify any research studies that conducted a traditional benefit –cost analysis to determine the long-term net present value savings, return on investment, or long-term payback related to the use of ASHRAE Standard 90.1-2010, ASHRAE Standard 189.1-2011, and the LEED or Green Globes green building certification systems.
Of the 25 studies that met the committee’s criteria for time frame, robustness, and relevancy to the DOD operating environment, only two (Turner, 2006; Kats, 2010) provided some analyses of net present value (NPV) benefits, return on investment, or payback associated with high-performance and green buildings. Those studies, however, did not evaluate the cost-effectiveness of the specific building standards or green building certification systems. Instead, they looked at the cost-effectiveness of green buildings compared to conventional buildings.
The DOD consultant’s report did conduct a traditional benefit-cost analysis for the specified building standards and green building certification systems. However, the committee had significant concerns about the data used for the analyses and the application of those data, such that it could not support the absolute NPV benefits calculated by the DOD consultant for the ASHRAE standards, LEED, or Green Globes.
Finding 2. There is some limited evidence to indicate that provisions within ASHRAE Standard 189.1-2011 may need to be selectively adopted if use of this standard is to be cost-effective in the DOD operating environment.
ASHRAE Standard 189.1-2011 contains mandatory requirements that limit the ability of DOD to adapt the standard to its operating environment. The foreword to ASHRAE 189.1-2011 states that “new provisions within the standard were not uniformly subjected to economic assessment” (p. 1) and that cost-benefit assessment was not a necessary criterion for acceptance of any given proposed change to the standard from the 2009 version.