'White House Down' director Roland Emmerich found it a challenge to shoot in one location.
The new action thriller - which stars Channing Tatum and Jamie Foxx - takes place entirely in the United States president's home and the filmmaker admits it was a tough task to make a film in just one setting.
He said: "It all takes place in one spot, you know - one house. It's a very big house but still, it's one house. You have to be much more aware of where are which rooms? Is this logical that it would be there? That was quite a challenge."
To prepare for the film, the director decided to take a tour of the White House - which is currently occupied by US president Barack Obama and his family - in Washington, DC, and was amazed by just how many guards patrol its hallowed halls.
He told Collider.com: "I looked very carefully how many Secret Service agents stand around. It's just incredible how much personnel is needed to guard this house. You try to find out the exact numbers, but nobody will ever give it to you."
'White House Down' sees Tatum star as a rejected Secret Service applicant who finds himself trying to save the president (played by Foxx) as gunmen storm the White House.
Tagged in Barack Obama Channing Tatum Roland Emmerich