Although data on the efficacy of energy- and water-saving building standards is scarce, a new report recommends that the Department of Defense continue to design new buildings and renovations to LEED silver certification standards, as it did in the case of the Fort Belvoir Community Hospital in Virginia. The increased constructions costs are negligible, the report says, and the possibility of savings over the long term are real. Wikimedia Commons/ MC2 Todd Frantom/U.S. Marine Corps
The National Research Council studies the research evidence on high-performance buildings and recommends a leadership role for the U.S. Department of Defense.
February 26, 2013—Building and renovating structures to meet various energy efficiency standards can significantly reduce water and energy use for a relatively small incremental construction premium. However, research into the different building standards and the cost-benefit results they produce is inadequate.
Those are the key findings of a new report, “Energy-Efficiency Standards and Green Building Certification Systems Used by the Department of Defense for Military Construction and Major Renovations,” prepared by a National Research Council (NRC) for the U.S. Department of Defense (DOD).
In the National Defense Authorization Act for Fiscal Year 2012, Congress required the DOD to undertake an analysis of the green building standards DOD uses in its applicable construction and renovation projects. Congress wanted a cost-benefit analysis and the return rate on investment for four standards commonly used by DOD: American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 189.1-2011; ASHRAE Energy Standard 90.1-2010; The U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) silver, gold, and platinum certifications; and American National Standards Institute (ANSI) accredited standards.
At the request of the DOD, the NRC formed the Committee to Evaluate Energy-Efficiency and Sustainability Standards Used by the Department of Defense for Military Construction and Repair to research the matter. The committee conducted an analysis of 25 studies published in 2004 or later that met its criteria for scientific robustness and relevancy to DOD operating environments.
The committee found that the incremental cost to build a high-performance building ranged between 0 and 8 percent, the largest study sample indicating a premium of just 2 percent. The authors note that construction costs typically account for between 5 and 10 percent of the total cost of a building over its lifespan, while operations and maintenance account for between 60 and 80 percent.
“Thus, the additional incremental costs to design and construct high-performance or green buildings are relatively small when considered as part of total life-cycle costs,” the report states.
Evidence reviewed by the committee indicates that those small incremental costs during construction can yield significant reductions in energy and water use. Of the 13 studies that evaluated actual energy use, all found high-performance buildings used less energy, the rate of savings ranging from 5 to 30 percent. Eight studies considered water use and found reductions of from 8 to 11 percent.
Measuring actual energy use is a significant point, according to the report. The committee found that the prevailing energy use models for high-performance buildings underestimate the actual energy use of a structure because the models assume building systems function at peak performance and do not include certain heat losses.
According to the report, “the difference between modeled energy and water use and actual energy or water use is important for facilities managers and other decision makers when communicating with other stakeholders,” according to the report.
The committee found that in the research of the nascent high-performance building trend, there were no traditional cost-benefit research studies to quantify long-term value and return on investment related to the commonly used standards the committee was investigating.
Indeed, the committee found that not all high-performance buildings use less energy than conventional buildings. The research also indicates that working to achieve a higher LEED rating did not always result in energy savings. The research is unclear as to why this happens, but the report indicates that building type and the technologies deployed are factors.
The report recommends that the DOD take a leadership role, developing energy use models by employing newly available data from federal buildings, which were all required to be metered by FY 2012.
“The data currently available to support decision making about investments in military construction and major renovation projects is inadequate,” the report states. “[The] DOD could work with the Department of Energy (DOE) and others to improve the available knowledge and databases related to high-performance buildings to the benefit of the federal government and society.”
Although the committee found the current data inadequate, it did recommend that the DOD continue to design new buildings and renovations with the goal of LEED silver certification or equivalent ratings. The committee found that the preponderance of available evidence points to the value of such ratings in providing a framework to reduce energy and water use.
A prepublication of the report is available here.