After 9/11, the U.S. intelligence community swelled.
More than 33 top-secret intelligence buildings were built or being built over the next nine years.
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That's about 17 million square feet just in and around Washington, D.C.
For perspective, that's basically 15 White Houses, seven U.S. Capitol Buildings and three Pentagons combined.
And those numbers are just from 2010. Since then, even more office space has been added just to house the intelligence community.
