I’m honestly not even sure what’s going on with Terminals 1, 2, and 3 (in the northeastern quadrant of the drawing). I can only assume they’ve been added onto many, many times, but the end result is morbidly complicated.
As if to offset that, Terminal 5 (northwestern quadrant) is just a bunch of simple almost-rectangles.
Paul Bogard created these terminal silhouette illustrations, and has made them available for use under a CC BY-SA 4.0 License.