4.11Established Building Setback Lines. Where a block is at least 40 percent occupied by permanent buildings at the time of the passage of this chapter, the average of the distances of the street walls of such buildings from the street right-of-way line shall be the requirements of each district, but in no case shall a setback of greater than 60 feet be required.

4.12 Irregular lots. All setbacks for irregular lots shall be determined by the planning and zoning officer according to principles set forth for yard setbacks in this Article.