MWAA has drawn up plans to add a new north concourse to Terminal C, replacing the office and support facility that's there. (Those who remember the construction of the current north terminal might remember this building as the "temporary north terminal" during that time.) US/AA might even pay for it, as it would allow them to consolidate operations behind one checkpoint at the north pier.

By the end of 2014, DCA will be operating at 40% above its passenger capacity.

http://www.flightglobal.com/news/art...ptions-400309/