Lawful uses, buildings or structures, existing at the time of an annexation, or change in the zoning code, may be continued even though it does not conform with this title and will be considered legal, nonconforming. Such nonconforming use, building or structure may be maintained and repaired as such in accord with all applicable codes and regulations. Any expansion of a nonconforming use or structure is limited to twenty-five percent of the floor area, or cubical content of the building, or of the service capacity of the use conducted all or partially in the open. A nonconforming use, building or structure may not be changed to another nonconforming use, building or structure. If a nonconforming use, building or structure is destroyed by fire, explosion or like cause to the extent of sixty percent or less of either its bulk or value, it may be reconstructed. However, such reconstruction must conform with all applicable codes and ordinances of the city.

No use, building or structure which has been made conforming may again be made by the owner nonconforming nor shall any nonconforming use, building or structure, which has ceased for six months, be again resumed. In all cases, the time frame commences upon notification by the administrator to the property owner.

Any incomplete nonconforming use, building or structure for which a valid building permit has been issued, prior to annexation or a change in the zoning code, may proceed in accord with the regulations at the time of permit issuance.

In any R district, a detached single-family dwelling may be erected on any lot of official record on the effective date of the ordinance codified in this title or upon annexation.

In any district where public water supply or sanitary sewer is not accessible, the minimum lot area and yard requirements must be increased as required by the Benton-Franklin District health department.

In the case of irregular lots where setback requirements cannot be literally applied, the administrator will establish yard areas to conform with the intent of this title. Except for fences, setback areas must be unobstructed by any building or structure. Setback lines are measured from property lines. Where no street exists, setbacks will be measured from proposed right-of-way lines of any city street plan.

The setback requirements on corner lots in all residential zones, residential, low density (RL), residential, medium density (RM), residential, mixed dwelling (RMD), and residential, high density (RHD), except the residential mobile home park (RMP), shall be as follows: twenty feet on both sides of the residence adjacent to a street, and ten feet for the back yard and the off-street side.

In the case of irregular lots or regular lots, created prior to the adoption of the ordinance codified in this chapter, that would be unable to be built on given their size or shape, a sight triangle will be utilized to determine the setback for a corner lot. This sight triangle area will be established by the public works director or city building official.

The following architectural features may project no more than three feet into any setback area: cornices, canopies, cantilever roofs, eaves, bay windows, balconies, and the like. Fire escapes may project no more than four and one-half feet if all projections are at least eight feet above ground level.

The following structures may exceed height limits permitted in the district in which located provided they do not occupy more than twenty-five percent of the area of the lot and are at least twenty-five feet in all parts from every lot line: church spires, belfries, cupolas and domes, monuments, water towers, observation towers, flagpoles, radio and television transmission and receiving towers; and outdoor theater screens, smokestacks, cooling towers, grain elevators, and other structures where the manufacturing process requires greater height. Radio towers of amateur radio operators must not overhang or extend over abutting property. The height of conditional uses will be as set out in the permit.

The maximum height of a structure on sloping lots will be measured vertically from ground level from that portion of the structure highest on the slope.