(a) In a Class U1, U2 or U3 District, every building erected shall have a rear yard.
(b) The least dimension of such rear yard shall be twenty percent (20%) of the depth of the lot, but such least dimension need not be more than forty feet, providing such least dimension shall in no case be less than one-half of the height of the building.
(c) Forty percent (40%) of the area of such rear yard may be occupied by one accessory building not more than sixteen feet in height, but on a corner lot, the rear line of which is identical with the side line of an interior lot, no such accessory building, if detached from the main building, shall be erected within twenty-three feet of any street line or within ten feet of the rear lot line, in a Class A-5 District, or five feet from the rear lot line in Class Al through A4 Districts. (Ord. 121-1962. Passed 12-17-62.)