Invariably, at the time the zoning ordinance is adopted or amended, certain uses which existed prior to the adoption or amendment will not conform to the regulations of the title. These are known as nonconforming uses, and in order to feasibly adopt the ordinance and so as not to cause undue economic hardship on owners of nonconforming uses, these uses are allowed to continue under special conditions as outlined in the following sections.

Subject to the provisions of this chapter, a nonconforming structure or use may be continued and maintained in reasonable repair, but shall not be altered or extended. The extension of a nonconforming use to a portion of a structure which was arranged or designed for the nonconforming use to a use at the effective date of the ordinance codified in this title is not considered an enlargement or expansion of nonconforming uses and may be allowed when the planning commission determines that such alterations or extensions are necessary to comply with other city, state or federal requirements.

If a nonconforming use, either of the property or a structure, is discontinued for a period of six months or more, then that nonconforming use is no longer legal, and subsequent uses shall conform to this title.

Except for signs, a structure conforming as to use but nonconforming as to height or lot coverage may be altered or extended provided the alteration or extension does not exceed the areas, height or coverage requirements of this title. A nonconforming sign shall not be altered or extended except to make it comply with the requirements of this title.

If a nonconforming use, structure or a structure containing a nonconforming use suffers damage or is destroyed by any cause, including intentional destruction exceeding 50 percent of its assessed value and is not returned to use to repair within six months, a future structure or use on the site shall conform to this title.