In the HC, BC, and LI Districts accessory buildings, structures, and uses may be located no closer than one foot to any property line except as follows: Where a nonresidential use abuts a residential use, the setback shall be two feet; where the HC, BC or LI District abuts an R-1, R-2, or BC District, the setback shall be not less than half the minimum required side yard of the abutting district.