Front yard requirements shall not apply to bay windows or balconies occupying, in the aggregate, not more than one-third of the front wall, nor to fences, chimneys, flues, belt courses, leaders, sills, pilasters, uncovered porches or similar features not over three feet high above the average finished grade and distant at least five feet from every lot line.
   In any district where the average depth of any two or more existing front yards on lots, within 100 feet of, and in the same block-front as, the lot in question, is less or greater than the least front yard depth prescribed, front yards may be varied. The depth of the front yard on such yard shall not be less than the average depth of the existing front yards or, in the case of a corner lot, the depth of the front yard on the lot immediately adjoining.  However, the depth of the front yard on a lot in an "R" District shall be at least ten feet and need not exceed sixty feet. (Ord. 340.  Passed 12-19-66.)