There's also rumored to be a secure bunker underneath the residence.
When loud blasts and construction noises were heard at Number One Observatory Circle in 2002, neighbors complained and received letters that read, "Due to its sensitive nature in support of national security and homeland defense, project specific information is classified and cannot be released."
The letter sparked rumors that a secure bunker was being built after the attacks of September 11, 2001.
A spokesperson for the US Navy told the BBC in 2002 that the construction was "an infrastructure and utility upgrade."
Newsweek's Eleanor Clift reported in 2009 that Biden revealed the existence of the bunker at an annual Gridiron Club dinner, but Biden's spokeswoman told Fox News that his comments were not reported accurately.
"What the vice president described in his comments was not — as some press reports have suggested — an underground facility, but rather, an upstairs workspace in the residence, which he understood was frequently used by Vice President Cheney and his aides," the spokeswoman said. "That workspace was converted into an upstairs guestroom when the Bidens moved into the residence. There was no disclosure of classified information."