Image c ourtesy Flickr user Mr.TinDC under a Creative Commons license. In 2008, the District of Columbia became the first jurisdiction in the United States to require private buildings to measure and disclose their energy performance. And now, six years later, the data is in and available for public consumption.

This week D.C. announced that it has released detailed data on the energy and water use of the area's largest privately owned buildings, making it the second jurisdiction in the country to do so, following New York City's lead. The D.C. data spans two years—2011 and 2012—and addresses energy use in both years as well as water use in 2012. While the District has 128,000 buildings representing more than 730 million gross square feet, the publicly available data provides a snapshot with a few caveats as the data collection process is being rolled out in phases. When the full program is implemented, it will apply to D.C. government buildings over 10,000 gross square feet and private buildings over 50,000 square feet, which in total would represent 49 percent of the District's total floor area--but a mere 1.6 percent of the District's buildings.

A few things to keep in mind about the recently released data: The District Department of the Environment's (DDOE) Green Building Report for 2012 explains that the 2011 data set represents 344 privately owned buildings that measure over 200,000 gross square feet for a total of 140 million gross square feet, and includes buildings that also reported data to the District in 2010. The 2012 data set, meanwhile, covers 490 privately owned buildings that measure over 150,000 gross square feet each for a total of 170 million gross square feet of real estate. The data does not, however, include Federal government buildings, nor does it account for public facilities not under the District's Department of General Services, such as facilities overseen by the D.C. Housing Authority, the Washington Convention Center, and the University of the District of Columbia. Other exemptions in the data collection process include foreign embassies and international institutions, as well as buildings that were built or sold during the reporting year. This last part is significant: according to the Green Building Report for 2012, DDOE estimates that half of the District's building stock over 50,000 square feet is sold each year, resulting in a potential 10 percent flux in the number of buildings reporting data each year.

Nonetheless, the benchmarking data is enlightening. Among the findings:

  • DC commercial buildings are by large out-performing their peers, with a median Energy Star score of 77 out of 100. In comparison, the national media score is 50.
  • The District's buildings are becoming more efficient, with energy use dropping 6 percent on average from 2010 to 2012. In addition, Energy Star buildings that reported data for 2010, 2011, and 2012 reported, on average, a three point increase in their Energy Star scores.
  • The performance scale is wide, with the least-efficient office buildings using more than 235 percent more energy than the most-efficient ones.
  • Age is just a number: there is no correlation between the age of a building and its energy performance.
  • Compliance is high, with more than 83 percent of the buildings required to report energy data doing so. The top reporting sector: Office buildings (88 percent). The least successful in reporting: Hospitals (42 percent).
  • DC is working to address the data gaps noted above. More than 70 embassies have signed a sustainability pledge to share their energy benchmarking data with the city, and the DDOE is working with the U.S. General Services Administration and Department of Energy to accelerate the federal government's disclosure of its facilities' energy performance, whose collection is mandated under the Energy Independence and Security Act of 2007.

The data set is expected to grow going forward as private buildings greater than 50,000 square feet must begin reporting annual data to the DDOE starting on April 1 of this year.
Click here to access the full data sets for 2011 and 2012.