On through lots one hundred fifty feet or less in depth, the height of a building on such lot may be measured from the sidewalk level of the street on which the building fronts. On through lots more than one hundred fifty feet in depth, the height regulations and basis of height measurements for the street permitting the greater height shall apply to a depth of not more than one hundred fifty feet from that street.

Roof structures specifically for the housing of elevators, stairways, tanks, ventilating fans or similar equipment required to operate and maintain the building, fire or parapet walls, skylights, architectural features or towers, flagpoles, chimneys, smokestacks, wireless masts and similar structures may be erected above the height limits prescribed in this title but no roof structure or any other space above the height limit prescribed for the zone in which the building is located shall be allowed for the purpose of providing additional floor space, or be taller than the minimum height requirement to accommodate or enclose the intended use.

However, the exception in this section does not apply if there is a specific provision elsewhere in this title for the protrusions under consideration.

Except as provided in this chapter, every required yard shall be open and unobstructed from the ground to the sky. No yard or open space provided around any building for the purpose of complying with the provisions of this title shall be considered as providing a yard or open space for any other building, and no yard or open space on any adjoining property shall be considered as providing a yard or open space on a building site whereon a building is to be erected.

When the common boundary line separating two contiguous lots is covered by a building or permitted group of buildings, such lots shall constitute a single building site and the yard spaces as required by this ordinance shall then not apply to such common boundary line.

Where two or more buildings are, by definition of this title, considered main buildings, then the front yard requirement shall apply only to the building closest to the front lot line.

The City Planner may adopt a formula or establish standard practices by which to determine appropriate and practical yards in all residential zones where geometric shape and dimensions and topography are such as to make the literal application of required yards impractical. After the adoption of such formula or standard practices, they shall be applied as an administrative act.

The depth of required front yards may be modified on unimproved lots intervening between lots having nonconforming front yards or between a lot having a nonconforming front yard and a vacant corner lot. A nonconforming front yard shall be deemed to be an area between the front lot line and the closest part of the main building, and which is greater or less in depth than that defined in this title as constituting a required front yard.

A building or structure shall not be erected or maintained on a lot which abuts a highway having only a portion of its required width dedicated and where no part of such dedication would normally revert to said lot if the highway were vacated, unless the yards provided and maintained in connection with such building or structure have a width or depth of that portion of the lot needed to complete the road width, plus the width or depth of the yards required on the lot by this ordinance, if any. This section applies to all zones and whether or not yards are required.

This section does not require a yard of such width or depth as to reduce the buildable width of a corner lot to less than forty feet.

Front yard requirements shall be measured from the front property line or the indicated edge of a street for which a precise plan exists.

All corner lots and reversed corner lots subject to yard requirements shall maintain for safety vision purposes a triangular area one angle of which shall be formed by the front and side lot lines separating the lot from the streets, and the sides of such triangle forming the corner angle shall each be fifteen feet in length, measured from the aforementioned angle. The third side of the triangle shall be a straight line connecting the last two mentioned points which are distant fifteen feet from the intersection of the front and side lot lines, and within the area comprising the triangle no tree, fence, shrub or other physical obstruction higher than forty-two inches above the established grade shall be permitted.

Front and side yard requirements shall not be applicable to dwellings and apartments erected above stores.

The following intrusions may project into any required yards, but in no case shall such intrusions extend more than two feet into such required yards:

In any "R" zone, no fence, wall or hedge over forty-two inches in height shall be permitted in any required front yard setback. In the required side yard or street side of either a corner lot or reversed corner lot, a six-foot high fence may be permitted when approved by the City Planner when the safety and welfare of the general public are not imposed upon. The issuing of a permit upon the approval of the City Planner shall be subject to special conditions which may vary due to the topography, building placement and vehicular or pedestrian traffic. On an interior lot, a wall or fence not more than six feet in height may be located anywhere to the rear of the required front yard.

Shrubs, flowers, plants and hedges not more than forty-two inches in height, and trees shall be permitted in any required yard, except as provided in Section 21.46.100.

The minimum width of the side yard upon which dwellings front shall be not less than ten feet.

Where two-family dwellings or multiple-family dwellings, group houses, court apartments or row dwellings are arranged so that the rear of such dwellings abut upon the side yards, and such dwellings have openings onto such side yards used as secondary means of access to the dwellings, the required side yards to the rear of such dwellings shall be increased by one foot for each dwelling unit having such an entrance or exit opening into or served by such yard, provided such increase need not exceed five feet.

Any building which is the only building on a lot or building site is a main building unless authorized by variance.

Through lots one hundred eighty feet or more in depth may be improved as two separate lots, with the dividing line midway between the street frontages, and each resulting one-half shall be subject to the controls applying to the street upon which such one-half faces. If each resulting one-half be below the minimum lot area as determined by this ordinance, then no division may be made and only one single-family dwelling may be erected upon such lot. If the whole of any through lot is improved as one building site, the main building shall conform to the zone classification of the frontage occupied by such main building, and no accessory building shall be located closer to either street than the distance constituting the required front yard on such street.

No lot area shall be so reduced or diminished that the lot area, yards or other open spaces shall be smaller than prescribed by this ordinance, nor shall the density of population be increased in any manner except in conformity with the regulations established by this title.

Greater lot areas than those prescribed in the various zones may be required when such greater areas established by the adoption of a precise plan in the manner prescribed by law, designating the location and size of such greater required areas.