The provisions of this chapter with regard to height shall not apply to church spires, steeples, belfries, clock-towers, noncommercial radio towers, flagpoles, chimney stacks, skylights, scenery lofts, antennas, water tanks, fire or parapet walls or roof structures for the housing of elevators, stairways, ventilating fans, air-conditioning equipment or similar equipment and structures, provided that such features shall be erected only to such height as is necessary to accomplish the purpose they are to serve.

No part of any structure erected pursuant to Subsection A to a height in excess of the height limit for the zone in which it is situated shall:

The property owner does not own any property adjoining such undersized parcel.

Dwellings or other principal uses are located on the lots adjacent to the undersized parcel.

The property owner cannot acquire property from any adjacent lot either because the owner of such lot refuses to sell or because such sale would render such adjacent lot in violation of this chapter with respect to side yard, width or bulk area requirements.

The undersized parcel and the dwelling to be erected thereon complies with all other requirements of this chapter.

Where a lot is situated between two lots, each of which is developed with a main building which projects beyond the established front building line as required by this chapter and has been so maintained since the enactment of this chapter, the minimum front yard requirement of such lot may be the average of the front yards of said existing buildings.

Where a lot adjoins one lot developed as described above and a vacant lot, the minimum front yard requirement of such lot may be the average of the front yard of the existing building and the established front setback line established by this chapter.

Where a lot to be built upon has frontage on a street which contains developed lots within the same block with front yard setbacks that are greater than the minimum setback in the Schedule of District Regulations, the minimum front yard setback of such lot to be built upon shall be based upon the average setback of surrounding properties with frontage on the same street. The average setback of surrounding properties shall be calculated using the front yard setbacks of the principal buildings on the two closest developed lots with frontage on the same street and within the same block.