floorNum

Unitless integer indicating the floor's distance from ground level. The ground floor is always defined as zero. Additional floors above ground are numbered 1, 2, 3, etc. Subterranean floors are numbered -1, -2, -3, etc. This convention is consistent with how most European buildings number floors. In North America its common to label the ground floor as the first floor; however Haystack requires the ground level to be assigned a floorNum of 0.