Stupid Question about the Vanishing Cabinet

[houyhnhnm102]

No: HPFGUIDX 141704

CV, confused:

> Also, is Filch's office in the basement? Otherwise, how could a
Vanishing Cabinet on the First Floor be dropped over Filch's office?:-s

houyhnhnm:

I think it is only in American usage that the floor of a building on
the ground level is called the first floor.  In most countries, and
I'm pretty sure in the UK, what Americans would call the second floor
is called the first floor.