Benchmarking for Military Buildings

A simple approach to energy benchmarking that tailors comparison models to unique buildings provides military facility engineers with a better way to measure building performance

 

By Colin Dunn, P.E., CEM, LEED AP, M.SAME, Ryan M. Macpherson, EIT, LEED Green Associate, M.SAME, and Amy C. Maples, M.SAME

 


 Naval Station Everett

The U.S. Environmental Protection Agency’s ENERGY STAR Portfolio Manager has helped Naval Station Everett successfully reduce energy use intensity by 40 percent over the last decade, even as total square footage increased at the installation. U.S. NAVY PHOTOS


 

With nearly 300,000 buildings and 2.2 billion-ft² under its watch, the Department of Defense (DOD) has a building footprint three times that of retail giant Walmart and civilian government agency, the U.S. General Services Administration. DOD’s facility energy expenditures totaled $4.1 billion in FY2013—or roughly 10 percent of its entire operation and maintenance expenditures for installation infrastructure.

 

In the commercial sector, accurate and robust energy benchmarking, achieved through adoption of ENERGY STAR’s Portfolio Manager, has led to annual energy savings potential of approximately 2.4 percent for benchmarked buildings. While the benefit of energy benchmarking has been demonstrated at individual defense installations, widespread adoption across the services generally has been limited. By using existing DOD energy usage databases and replicating some simple benchmarking methodology, installation managers and investment planners can realize a potential $100 million total annual energy savings.

 

CASE STUDY: NAVAL STATION EVERETT

Naval Station Everett, located just north of Seattle in the Pacific Northwest, success­fully reduced energy use intensity by 40 percent in 2013 compared to a 2003 base­line. The savings were not just from clos­ing facilities. In fact, the installation’s total square footage increased over this period. Yet Everett still saved more than $400,000 in energy costs. A significant portion of these savings is attributable to intelligence gained through baselining the energy performance of Everett’s building portfolio in the U.S. Environmental Protection Agency’s ENERGY STAR Portfolio Manager.

Portfolio Manager normalizes building performance data across a variety of exter­nal factors, such as weather or daily usage, and compares buildings against a national dataset from the Commercial Building Energy Consumption Survey. The resulting output is a score from 1 to 100 that gives insight into relative performance compared to similar building types. Buildings with an ENERGY STAR score of 75 or higher are eligible for recognition as high-performers.

Using ENERGY STAR scoring data, Naval Station Everett identified poor performing buildings in its portfolio, many with a relative score less than 25, and focused retrocommissioning and modernization investments on these buildings. Benchmarking has allowed the base to monetize potential energy savings from equipment upgrades and building automation schedule changes, and make data informed decisions about divestments.

From 2011–2013, 12 buildings at Naval Station Everett earned ENERGY STAR recognition, which has helped to raise occu­pant awareness. From an owner perspec­tive, the ENERGY STAR plaque serves as a great energy conservation tour stop and a good first public milestone towards exist­ing building energy conservation. When building occupants can see the impact of energy savings, they can better see their role in conservation efforts.

 

OVERCOMING LIMITATIONS

While Portfolio Manager is utilized by more than 40 percent of the commercial U.S. building market, there are inherent barriers to widespread DOD adoption. First, the mission-specific usage profiles of defense buildings do not align well with commercial sector averages. For example, a DOD maintenance facility is not the same as a manufacturing or industrial plant from an energy performance perspective as it operates on different schedules and specializing in specific processes, such as corrosion control. Of Naval Station Everett’s 54 buildings onsite, only 26 loosely matched with Commercial Building Energy Consumption Survey building types and were capable of benchmarking energy use.

Second, a general reluctance to upload DOD facility and energy data into a civilian tool prevents wider military adoption of existing benchmarking tools. Even though owners of large building portfolios no longer need to manually enter buildings into Portfolio Manager (which can take up to 30 minutes per building), semi-automated data import options remain challenging and time consuming. A solution that pre-populates the entire database for the user allows limited available time to be spent on understanding building performance rather than responding to data calls.

With these inherent benefits and limita­tions in mind, Noblis, a nonprofit science and engineering firm headquartered in Falls Church, Va., leveraged internal research and development funds to develop a simple, repeatable methodology for DOD components to benchmark buildings using existing data resources.

 

BEQ at NS Everett

Completed in 2009, the Charles Luke Milam Bachelor Enlisted Quarters, achieved ENERGY STAR recognition in 2011 and is Naval Station Everett’s first LEED Gold building. The base now has 12 ENERGY STAR facilities.


 

BENCHMARKING METHODOLOGY

Benchmarking DOD’s existing building stock occurs in four main phases.

Phase I: Gather DOD Building and Utility Data. A critical aspect of perform­ing any building analysis is determin­ing what data is available. With sources such as the Air Force Automated Civil Engineer System (ACES) and the Navy Comprehensive Utilities Information Tracking System (CIRCUITS), DOD has significant resources available to develop benchmarking models without requir­ing new investments. For developing the model, building data was collected from the Real Property Asset Database and available building level utility data was gathered from through CIRCUITS and ACES.

Existing service and installation-level databases were used to identify key similarities and differences in the build­ing stocks compared to the pre-existing ENERGY STAR models. The data quality was reviewed across several attributes, including frequency of readings (monthly or yearly), to assure consistency for model calculations and ratings. It also was essen­tial to verify that energy usage was actual data from building meters rather than estimated data.

Phase II: Select the Sample Set of Building Type. The intent of the bench­marking model is to address the uniqueness of DOD’s building stock, which makes the selection of building types critical. This requires a sufficient number and geographic distribution of buildings to make the analysis relevant for the entire building portfolio. Data reviews and service discus­sions focused on desired end-of-process intelligence were used to select the desired sample set of buildings to use in developing the demonstration model.

For the demonstration at Naval Station Everett, three facility types were chosen: barracks, maintenance facilities, and research test and evaluation facilities.

Phase III: Choose Model Variables for Quality Analysis. This phase perfects the criteria for rating the individual buildings and assigning numerical scores in the 1-100 range. At Naval Station Everett, multiple model approaches utilizing different types of numerical analyses were used to identify the most significant variables for develop­ing ratings on individual buildings.

A quality model (usable ratings) was developed such that it needed the fewest variables and incorporated regional weather data to provide the ratings with normalized energy use numbers. Weather normalization was performed with two additional variables: heating and cooling degree days, with a 65°F base temperature, for each location. A multivariable linear regression approach was chosen since it produced consistent results in scoring indi­vidual buildings. Separate regressions then were developed for each building subtype. The predicted energy consumption of each building was determined using the regres­sion for its building subtype, standardized by building location, type, size and age. Numerical scores were assigned using the percent difference between predicted and actual energy consumption.

Phase IV: Prototype the Tool for Web Interface. To encourage installation commanders to harvest these energy savings, it is critical to communicate information clearly. Noblis developed a web-based tool that displays the data and building score relative to similar facilities. Graphics help users easily identify buildings as “High,” “Average,” or “Low” performers. Users also can sort buildings by score, age, square footage and energy consumption.

 

PLANNING FOR THE FUTURE

Using this simple and repeatable meth­odology to benchmark DOD’s extensive portfolio can lead to tangible monetary savings, better understanding of relative building performance, and data-driven investment and divestment decisions.

By following this approach to developing DOD-specific benchmarking capabilities, installations can realize benefits at scale and across the entire portfolio.

  


 

Colin Dunn, P.E., CEM, LEED AP, M.SAME, is Project Manager, Ryan M. Macpherson, EIT, LEED Green Associate, M.SAME, is Lead Engineer, and Amy C. Maples, M.SAME, is Chemical Engineer, Noblis Inc. They can be reached at 703-610-2352, or This email address is being protected from spambots. You need JavaScript enabled to view it." target="_blank">This email address is being protected from spambots. You need JavaScript enabled to view it.; 703-610-2898, or This email address is being protected from spambots. You need JavaScript enabled to view it." target="_blank">This email address is being protected from spambots. You need JavaScript enabled to view it.; and 571-422-3625, or This email address is being protected from spambots. You need JavaScript enabled to view it." target="_blank">This email address is being protected from spambots. You need JavaScript enabled to view it., respectively.