What we know about the secret White House bunker — and the 'massive' military complex beneath Trump's new ballroom Inside the Presidential Emergency Operations Center. The White House/Getty Images The Presidential Emergency Operations Center was first built for FDR during World War II in 1942. The PEOC served as a command center in the aftermath of September 11. Trump confirmed the construction of a new military complex beneath the planned White House ballroom. When people see the White House for the first time in person, they often remark that it looks small from the outside. Matt Costello, chief education officer and director of the David M. Rubenstein National Center for White House History, told Business Insider that appearances can be deceiving. "There's a lot more to the White House than meets the eye," he said. "It has six floors, about 55,000 square feet. There are two sub-basements underneath the house that were part of the Truman renovation.…