I’ve worked in two U.S. buildings with Both ground and first floors. The buildings were built into a hill so street level entered the first floor, but parking entered the ground floor. Very easy to get confused until you figure it out.
To add to your confusion, when you add a mezzanine floor to a UK building you get ground floor, mezzanine, first floor, second floor, so the lift buttons go G M 1 2 3…
I’ve worked in two U.S. buildings with Both ground and first floors. The buildings were built into a hill so street level entered the first floor, but parking entered the ground floor. Very easy to get confused until you figure it out.
To add to your confusion, when you add a mezzanine floor to a UK building you get ground floor, mezzanine, first floor, second floor, so the lift buttons go G M 1 2 3…