(a)   Average Depth of Front Yards. In the A and R Districts, where the average depth of at least two existing front yards on lots within 100 feet of the lot in question and within the same blockfront is less or greater than the least front yard depth prescribed elsewhere in the Zoning Ordinance, the required depth of the front yard on such lot shall be modified. In such case, this shall not be less than the average of the depth on the two lots immediately adjoining, or in the case where there are no buildings on both of the lots immediately adjoining, the average depth of the front yards on lots within 100 feet of the lot in question and within the same block front; provided, however, that the depth of a front yard on any lot shall be at least ten feet and need not exceed fifty feet.
(1)   Steep slopes; front yard garage. In the A and R Districts, where the natural slope of a lot within the required front yard has an average slope, normal to the front lot line at every point along such line, of such a degree or percent of slope that is not practicable to provide a driveway with a grade of twelve percent (12%) or less to a private garage conforming with the requirements of the Zoning Ordinance, such garage may be located within such front yard, but not in any case closer than six feet from the front lot line.
(2)   Double frontage lots. Buildings on lots having frontage on two nonintersecting streets need not have a rear yard, if an equivalent open space is provided on the lot in lieu of such required rear yard; applicable front yards must be provided, however, on both streets.
   (b)   Rear and Side Yards. In computing the depth of a rear yard of the width of a side yard, where the rear or side yard abuts an alley, one-half of the width of the alley may be included as a portion of the required rear or side yard, as the case may be; provided, however, that no side yard shall be less at any point than three feet, and no rear yard less than ten feet. (Ord. 94-84. Passed 7-9-84.)