Here are some theories: https://www.reddit.com/r/answers/comments/2fricv/why_do_airport_terminals_have_such_large_high/ https://www.reddit.com/r/answers/comment

Here are some theories: https://www.reddit.com/r/answers/comments/2fricv/why_do_airport_terminals_have_such_large_high/ https://www.reddit.com/r/answers/comments/2fricv/why_do_airp... Summary: prevents claustrophobia/overheating, allows high signs to be seen from far away, possibly structurally sounder for a wide room to be higher, aesthetics.