Since somebody mentioned Pentagon, I want to talk about the building I worked.
It was constructed prior to official desegregation, so it has twice the number of bathrooms needed for the number of employees (separately for both races).
But I am not bitter at all, and I am talking about toilets.
I want to talk about that huge parking space for 10.000 vehicles.
Try to avoid the same kind of mistake: forget about last century standards.
Don't waste your time designing garages. Think of roofs in forms of landing decks.
I would think of it as a dirigible's deck on the top of a skyscraper.
Nobody knows what kind of air transport people will have in the Twenty 2nd Century.
All we know that the oldest successful human flight technology is still around.
An airship deck is the safest thing to suggest. The central might need some sort of a hovercraft areas.