The Arch is Everything!
The door is pretty much the key ingredient in the library's design that lends to its overall look. My friend Joe had drafted several wonderful blueprints and we finally decided that the arch would need to be the door. (Note: some of what follows is a recap of that earlier design post, so I'll summarize.)
The arch and pillar design is based on the iconic headquarters of a certain team of superheroes, maybe you've heard of them--the Justice League!