With respect to the formulas referenced in Sec. 1.1409(e)(1) and Sec. 1.1409(e)(2), the space occupied by an attachment is presumed to be one (1) foot. The amount of usable space is presumed to be 13.5 feet. The amount of unusable space is presumed to be 24 feet. The pole height is presumed to be 37.5 feet. These presumptions may be rebutted by either party. [66 FR 34581, June 29, 2001]