Lots existing prior to the adoption of this chapter and future amendments may contain buildings, structures or uses which would be prohibited, regulated or restricted under the terms of this chapter or future amendments.

It is the intent of this chapter to permit these nonconformities to continue until they are removed but not to encourage their survival. Such uses are declared by this chapter to be incompatible with permitted uses in the zones involved. Nonconformities shall not be enlarged upon, expanded or extended nor be used as grounds for adding other structures or uses prohibited elsewhere in the same zone.

A nonconforming use of a structure, land, or both, shall not be extended or enlarged after passage of this chapter, nor shall additional uses of a nature which would be prohibited in the zone involved be allowed.

To avoid undue hardship, nothing in this chapter shall be deemed to require a change in the plans, construction or designated use of any building on which actual construction was lawfully begun prior to the effective date of adoption or amendment of this chapter and upon which actual building construction has been diligently carried on. ("Actual construction" is hereby defined to include the placing of construction materials in permanent position and fastened in a permanent manner; except that where demolition or removal of an existing building has been substantially begun preparatory to rebuilding, such demolition or removal shall be deemed to be actual construction, provided that work shall be diligently carried on until completion of the building involved.)

Notwithstanding limitations imposed by other provisions of this chapter, a single-family dwelling and customary accessory buildings may be erected on a single lot of record at the effective date of adoption or amendment of this chapter, except in the Highway Commercial District. Such lot shall be in separate ownership and not of continuous frontage with other lots in the same ownership. This provision shall apply even though such lot fails to meet the requirements for area or width, or both, that are generally applicable in the zone, provided that yard dimensions shall conform to the following requirements:

If two or more lots or combinations of lots and portions of lots with continuous frontage in single ownership are of record at the time of passage or amendment of this chapter, the lands involved shall be considered to be an individual parcel for the purposes of this chapter. No portion of said parcel shall be used or sold which does not meet lot width and area requirements established by this chapter, nor shall any division of the parcel be made which leaves remaining any lot with width or area below the requirements stated in this chapter.

No such nonconforming use shall be enlarged or increased, nor shall the lot be extended at the effective date of adoption or amendment of this chapter.

No such nonconforming use shall be moved in whole or in part to any other portion of the lot or parcel occupied by such use at the effective date of adoption or amendment of this chapter.

If any such nonconforming use of land ceases for any reason for a period of more than 90 days, any subsequent use of such land shall be a conforming use, meeting the regulations specified by this chapter for the zone in which such land is located.

No such structure shall be enlarged or altered in a way which increases its nonconformity.

If the structure is destroyed by any means to an extent of more than 50% of its replacement cost at time of destruction, as determined by the Planning and Zoning Commission, it shall not be reconstructed except in conforming use, meeting regulations specified by this chapter for the zone in which such structure is located.

If the structure is moved for any reason for any distance whatever, it shall thereafter conform to the regulations for the zone in which it is located after it is moved.

No structure of nonconforming use, except dwellings, shall be enlarged, extended, constructed, reconstructed, moved or structurally altered except in changing the structure to a conforming use.

Any nonconforming use may be extended throughout any part of a building which was manifestly arranged or designed for use at the time of adoption or amendment of this chapter, but no such use shall be extended to occupy any land outside such building.

If no structural alterations are made, any nonconforming use of a structure or a structure and premises may be changed to another nonconforming use, provided that the Board of Zoning Appeals, either by general rule or by making findings in the specific case, shall find that the proposed use is equally appropriate or more appropriate to the zone than the existing nonconforming use. In permitting such change, the Board of Zoning Appeals may require appropriate conditions and safeguards in accord with the provisions of this chapter.

Any structure or combined structure-and-land in nonconforming use replaced by a conforming use shall not thereafter revert to a nonconforming use. The new conforming use shall meet all district requirements.

In any residential district, when a nonconforming use of a structure or premises, or both, is discontinued or abandoned for six consecutive months or for 18 months during any three-year period, the nonconforming use shall not be resumed.

Where a structure and premises are in nonconforming use, voluntary removal or a destruction of the structure shall eliminate the nonconforming status of the land. Further use of the land shall conform to district regulations.

Nothing in these regulations shall prevent the restoration of a nonconforming building or structure destroyed by fire, windstorm, flood and explosion or act of public enemy or accident or prevent the continuance of the use thereof as it existed at the time of such destruction, provided that a zoning certificate is obtained and restoration begun within one year of such destruction.

On any building devoted in whole or in part to any nonconforming use, work may be done in any period of 12 consecutive months on ordinary repairs or on repair or replacement of nonbearing walls, fixtures, wiring or plumbing to an extent not exceeding 10% of the current replacement value of the building, provided that the cubic content of the building, as it existed at the time of the passage or amendment of this chapter, shall not be increased.

Nothing in this chapter shall be deemed to prevent the strengthening or restoring to a safe condition of any building or part thereof declared to be unsafe by any official charged with protecting the public safety upon order of such official.