A second report using the Davis Langdon database (Matthiessen and Morris, 2007) compared the construction costs of 83 buildings seeking LEED 2.1 and 2.2 New Construction certification to 138 non-LEED-seeking buildings (the samples included five different building types). Findings from the study were the following:
Kats (2010) found that the owners or owner’s representatives of 170 green buildings reported the median additional cost was 1.5 percent more to build a green building compared to a conventional building. The large majority of green building owners reported additional incremental costs between 0 and 4 percent, although the total range was 0 to 18 percent. The author concluded that most green buildings cost slightly more than similar conventional buildings to construct. Generally, the higher the certification level, the greater the cost premium, but all LEED levels could be achieved for minimal additional cost.
Three studies looked at the incremental costs associated with energy efficiency or LEED certification of federal buildings. Stephen Winter Associates (SWA, 2004) provided a detailed and structured review of both the capital and soft cost implications of achieving Certified, Silver, or Gold LEED ratings for the two building types most commonly constructed by the GSA: a five-story courthouse and a mid-rise federal office building. The study indicated that there was an inherent degree of variability to LEED construction cost impacts. However, the authors concluded that many Silver-certified projects could be built at a cost that was within 4 percent of the cost for a similar non-LEED-certified courthouse or office building, as well as occasional LEED-Gold-certified projects.
The IHS conducted a study (IHS, 2006) to evaluate the potential cost impacts of achieving a LEED-certified or a LEED-Silver certification on its facilities, which are primarily hospitals and other healthcare-related buildings. Among the study findings were the following:
Caprio and Soulek (2011) sought to determine the difference in initial investment (incremental construction costs) for building energy-efficiency enhancements intended to meet federal mandates. Benefit-cost analyses were conducted for the U.S. Army’s new construction standard designs for FY 2013 for the five most commonly constructed Army building types. The results were based on total energy use and were modeled, not measured. The authors noted that the study was able to show the energy effectiveness of a range of efficiency measures, but it was not able to show the cost-effectiveness of individual measures, nor was it able to optimize the designs for the highest energy performance at the lowest costs. They concluded, however, that (1) significant energy savings were possible for all climates, and (2) buildings achieving 25 to 35 percent energy savings would yield the maximum energy savings for