In NBC-2015, when calculating hn and hx to be used for Ax (height factor), if I have a piece of equipment sitting on the ground outside, only elevated by a skirt, hx and hn are 0, or is hx (elevation on structure) the skirt length, and hn (structure overall height) is the ground to the top of the piece of equipment?


hi, hn, hx = the height above the base (i = 0) to level i, n, or x respectively, where the base of the structure is the level at which horizontal earthquake motions are considered to be imparted to the structure,