As Anne Arundel County tries to prepare for growth at Fort Meade, there's one question mark that has nothing to do with the government-worker relocation better known as BRAC. It's the National Security Agency, and how much it will expand.

A lot, the county thinks. Possibly.


Not surprisingly, county leaders are having a hard time getting the secretive "No Such Agency" to loosen its lips.

What we do know (because even secretive agencies have to file notices with the Federal Register) is that NSA wants to build 5.8 million square feet of space at Fort Meade over a 20-year period -- enough to house 11,000 employees.

What we don't know is whether those employees would be holding 11,000 new jobs, or whether they're current employees who will be moved from other buildings on and off Fort Meade. Or some combination of the two options.

What's this got to do with real estate wonkery, you ask? Several things, as it happens.

--If NSA really does add thousands of jobs, that's good news for home sellers within commuting distance. Jobs and housing are inextricably linked. More people with jobs means more who can afford to buy a house or pay the mortgage they already have.

--More jobs also means more people on the roads at rush hour. Anne Arundel County leaders are concerned about traffic snarls just with BRAC workers, never mind NSA recruits, and with tax collections falling it's not an easy time to be expanding roads or transit. (Anne Arundel County Executive John R. Leopold joked Friday that BRAC stands for "Better Rely on Assistance from the County" because the state is cutting back and "the stimulus money, while helpful, is not really going to provide the shot in the arm for our transportation projects.")

--What if NSA isn't adding jobs but just moving them from offices outside its Fort Meade campus? A lot of landlords will be scrambling for new tenants, said Matthew M. Aid, author of The Secret Sentry: The Untold History of the National Security Agency. He said NSA has about 5,000 employees in something like 50 offices and warehouses near Fort Meade. (That's on top of at least 20,000 NSA personnel on base, he said.)

Aid has a great stat to illustrate the sheer size of this agency. And as it happens, it's housing-related.

The amount of space NSA is using, or at least was using in the middle of the 1990s, adds up to 7 million square feet in and around Fort Meade, he says. That's the equivalent of -- are you ready for this? -- 3,400 four-bedroom houses.

Not McMansion-sized houses, mind you, but still.