Which makes sense, as there can't be "negative" objects, mostly.
Building floors are more ambiguous - there can be basement, ie "negative" floors. So, floors in continental Europe are generally indexed 0-based (basements ..., -2, -1, ground floor = 0, upper floors 1, 2, ...). A German friend of mine caused some confusion when she checked into her student dorm at a US college, and having being told that her room was on the first floor, asked whether there was an elevator, as she had heavy suitcases.
You can have multiple basement levels, which get numbered again. 1er Sousl-sol, 2eme Sous-sol etc. The ground floor might not be explicitly labeled as zero but the number between "one up" and "one down" is still zero.
Building floors are more ambiguous - there can be basement, ie "negative" floors. So, floors in continental Europe are generally indexed 0-based (basements ..., -2, -1, ground floor = 0, upper floors 1, 2, ...). A German friend of mine caused some confusion when she checked into her student dorm at a US college, and having being told that her room was on the first floor, asked whether there was an elevator, as she had heavy suitcases.