Jia Panpan (up front) and Jia Yueyue (in the background) in the second indoor exhibit at Panda Passage. You can get exceptionally close to the giant pandas here and I took another photo just inches from Jia Panpan!
This picture shows the majority of the space, although there is a bit more space on both the left and right sides of this photo. This exhibit has a much greater percentage of usable space than the other indoor exhibit at the Calgary Zoo and the indoor exhibits at the River Safari Singapore, both of which have steep areas for open-moat style viewing.
@geomorph The two indoor exhibits are a total of 431 square meters (4,639 square feet). The two outdoor spaces (one not visible to the public) are a total of 1,512 square meters (16,275 square feet).
I am not sure of the exact size of giant panda exhibits in the US, but I believe that the exhibits at the Calgary Zoo are bigger than those at the San Diego Zoo or Memphis Zoo, but the total space for pandas at the National Zoo (3 outdoor exhibits) is greater.