The height regulations prescribed herein shall not apply to television and radio tower, church spires, belfries, monuments, tanks, water and fire towers, stage towers, scenery lofts, cooling towers, ornamental towers and spires, chimneys, elevator bulkheads, smokestacks, necessary public or private utilities, conveyors, flagpoles and necessary mechanical appurtenances.

Public or semi-public service buildings, hospitals, institutions or schools, where permitted, may be erected to a height not exceeding 45 feet and churches and other places of worship may be erected to a height not exceeding 75 feet when each of the required yards is increased by one foot for each two feet of additional building height above the height regulations for the district in which the building is located.

Where 51 percent or more of the frontage within a block is occupied or partially occupied by a building or buildings with front yards of less depth than required by this chapter, the remainder of that block front yard line shall conform with the setback requirements of this chapter.

No solid fence, structure or vegetation placed or allowed to grow within 20 feet each way from a corner or intersecting street right-of-way lines shall exceed four feet in height. A four-foot see through fence is allowed.

Open or unenclosed terraces, porches or roof eaves or extensions may project into the required front yard for a distance not to exceed four feet; provided, however, no supporting structure for such projections may be located within the required front yard. An unenclosed canopy for a gasoline filling station may extend into the required front yard; provided, such extension shall not be closer than ten feet to a lot line.