AFAIK, we Brits are holding firm to our numbering system, and not capitulating to the “first = ground” hegemony 
Incidentally, at my halls of residence at university (I went to Sheffield, which is a tad hilly), you entered on the second floor (numbered 2), but thanks to the strange topography thereabouts, there were two floows below that at one end of the building, numbered 1 and 0. My room was on floor 2, so I’d go in the main entrance at ground level, walk a short distance down the corridor to my room, without climbing any stairs, look out of the window and find myself two storeys above the ground! Gave me a shock when I first saw my room, I can tell you…