The Natural Resources Defense Council (NRDC) recently published the results of a 12-month case study on an energy management and performance improvement initiative implemented by The Tower Companies (Tower) in three of its large multitenant office buildings in Washington, D.C. Tower, a real estate development company based in Rockville, Md., has a portfolio that includes 4.5 million square feet of office buildings, 1,500 apartments, regional malls and hotels in “eco-progressive” live/work/play communities.
The goal of Tower’s initiative, while modest, is one that still manages to elude many property owners: to increase overall operational efficiency without spending a large amount of money. Tower spent significant time researching the best methods and tools by which to accomplish this goal, and came to the conclusion that neither technology nor consultative services alone would achieve the desired result. The key was to combine the two. The centerpiece of the initiative thus involved engaging AtSite, Inc. to deliver a range of building performance solutions, all of which aimed to increase energy efficiency in the subject buildings. The second element involved engaging HVAC Concepts, Inc. to provide a detailed alarm service for the building systems.
AtSite’s approach combined technology with consultative support. The firm conducted a detailed assessment of each building, delivered a plan for improvement, monitored real time energy use in each facility and delivered actionable, non-capital-intensive recommendations to building engineers through continuous communication, as well as at standing monthly meetings. During the study period, NRDC observed AtSite engineers conducting building assessments and attended monthly meetings to gain an understanding of the methodology and data used during the energy management initiative. To determine the energy savings resulting from the initiative, NRDC established a baseline of whole-building electricity usage during the prior 12-month period and compared that to usage in the study year. The research team then normalized the data against weather and occupancy and watched for anomalous events.
Tower’s energy management initiative achieved a 13.2 percent reduction in electricity use across all three buildings, showing that substantial gains are possible when owners “operate their buildings with attention devoted to reducing the amount of energy wasted.” The initiative was highly profitable: Savings from reduced electricity use in the first year alone exceeded total project expenses by more than 60 percent.
The case study concluded the following:
- Energy savings do not require major capital improvements or retrofits that could cause disruption to an occupied office building;
- The recommended measures resulted in more comfortable, more efficient buildings for both owners and tenants;
- The observed results occurred in buildings that already were efficient at the outset (with initial Energy Star scores of 71, 78 and 86, which rose to 91, 87 and 88 by the end of the study period); and
- While better information can provide value, “the personal engagement of an energy management expert was effective in a way that technology alone might not be.”
NRDC launched the study in order to answer two questions: Are claims of 10 to 20 percent energy savings real? If so, what explains those savings? The answer to the first is a resounding “yes,” as illustrated in the table on the previous page; the response to the second is twofold: catching operational drift quickly, not weeks or months after the fact, and involving trusted advisers who communicate regularly with building engineers.
For more information:
“Real Time Energy Management: A Case Study of Three Large Commercial Buildings in Washington, D.C.,” by Philip Henderson and Meg Waltner, Natural Resources Defense Council, October 2013,