WASHINGTON, DC-In the Washington, DC area, the date Sept. 15, 2011 has taken on a special and--depending in which submarket your fortunes rest--possibly terrifying implications. That is the date government agencies will have to comply with the Base Realignment and Closure, the 2005 decision by the US Department of Defense to reorganize its military base structure.

Its impact on the area cannot be understated: some 15 million square feet of office space will be affected along with new opportunities for retail and housing near the forts in question, according to a new Cassidy Turley report.

But as he set about to conduct the research, Cassidy Turley’s Jeff Kottmeier noticed something strange about that date. It was, surprisingly, given that it was set by the military, not carved in stone. “I think that realization has caught a lot of people off guard,” he tells GlobeSt.com. “Everyone has had in their head that the magic deadline is September 15, but it is becoming clear that not all of the agencies will be moving on that date.”

Determining exactly how many agencies will stay put and for how long is not easy as much of this information is not being made public by the Defense Department. But some rough approximations have been made. In Arlington County, one-third of BRAC-affected office space will be released in 2010/2011, while the other two-thirds will be released in 2012 or later. Furthermore, the perimeters of BRAC could still change with the election.  Timing may become even more opaque for some agencies, Kottmeier says. In an earlier interview with GlobeSt.com before the November elections, Joe Brennan, senior vice president at

Jones Lang LaSalle, said a Republican victory in the House could change some space requirements. He pointed to the discussions Reps. Eleanor Holmes Norton and Jim Moran had been having about the Department of Defense and its space requirements. “Norton and Moran say some of the functions of the DoD, with a lot of civilian employees, don’t need to have all of the security criteria for buildings,” said Brennan. “But there are others who argue that, yes, the DoD does need that for all of its functions. If the House goes Republican there is the potential for a shift in those talks.”

Perhaps observers should not be too surprised at the shifts. About faces have been part of BRAC ever since 2005. For instance, when the BRAC recommendations were first announced, an estimated 7,000 jobs from the Washington Headquarters Services were supposed to relocate from Alexandria, VA to Fort Belvoir, VA. Since then, it was decided that 6,400 jobs will transfer instead to the 1.4 million square foot Mark Center in Alexandria, VA, which is close to the agency’s current location.