In Australia multi level buildings have a ground floor then a first floor and then a second floor and so forth.
As I understand in North America it works that what we call the ground floor is the first floor and so our first floor will be their second floor.
I have readers all over the world. Is your ground level floor called ground level or first floor?
Over to you for an answer from England, Belgium, Canada, South Africa, France, Japan, India and anywhere I have missed out. I will already guess that ground floor then first floor is used in Britain.
I actually think the North American system makes more sense, though it is not what I am used to.