In Districts "R1-8", "R1-16", "R1-40", "R-2", "R-3" and "R-4" where lots comprising fifty percent (50%) or more of the frontage on the same side of the street between two (2) intersecting streets, (excluding reverse corner lots) are developed with buildings having front yards with a variation of not more than ten (10) feet in depth, the average of such front yard shall establish the minimum front yard depth for the entire frontage. Provided that the Board of Zoning Adjustment may establish a reasonable setback in case of hardship or where the configuration of the ground and buildings is such as to make conformity with the front yard requirements impractical.

In Districts "A-1", "R1-40", "R1-16", "R1-8" "R-2", "R-3", "R-4", "C-1", "C-2", "M-1" and "M-2", where buildings located in the same block on the same side of the street have provided front yards of greater or less depth than herein required, the Planning Commission and Board of Aldermen may establish setbacks for buildings or structures constructed hereafter.

Every part of a required yard or court shall be open from its lowest point to the sky unobstructed, except for the ordinary projection of the cells, belt courses, cornices, chimneys, buttresses, ornamental features and eaves; provided however, that none of the above projections shall extend into a court more than six (6) inches nor into a minimum yard more than twenty-four (24) inches; and provided further, that canopies or open porches having a roof area not exceeding sixty (60) square feet may project a maximum of six (6) feet into the required front or rear yard; and existing open porches extending into the required yard shall not be enclosed.

An open fire escape may project into a required side yard not more than half the width of such yard, but not more than four (4) feet from the building. Fire escapes, solid-floored balconies and enclosed outside stairways may project not more than four (4) feet into a rear yard. A below grade exterior stairway shall have a rail not less than three (3) feet in height surrounding the below grade area.

On any lot no topographical grade nor wall, sign nor other structure, nor plant growth of any type which would interfere with visibility of drivers on the public street shall be permitted or maintained higher than three (3) feet above the adjacent curve level from the front of the house forward to the pavement.

No rear yard shall be required in Districts "C-1", "C-2", "M-1" and "M-2" inclusive on any lot used for business or industrial purposes, the rear line of which adjoins a railway, right-of-way or which has a rear railway track connection.

In computing the depth of a rear yard for any building where such yard abuts an alley, one-half (½) of such alley may be assumed to be a portion of the rear yard.

A through lot having one (1) end abutting a limited access highway or thoroughfare with no access permitted to that lot from said highway shall be deemed to front upon the street which gives access to that lot.