If, within the zoning districts established by this chapter or due to amendments that may later be adopted, there exists lots, structures or uses of lots which were lawful before this chapter was passed or amended but 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 those nonconformities. Such uses are declared by this chapter to be incompatible with authorized uses in the zoning district involved. It is further the intent of this chapter that nonconformities shall not be enlarged upon, expanded or extended, nor be used as grounds for adding other signs, structures or uses prohibited elsewhere in the same zoning district, unless the Zoning Hearing Board shall interpret that the enlargement, expansion or extension is necessitated by the natural expansion and growth of trade.

To avoid undue hardship, nothing in this chapter shall be deemed to require a change in the plans, construction or designated use of any structure on which actual construction was lawfully begun prior to the effective date of adoption or amendment of this chapter and upon which actual construction has been diligently commenced. "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 structure has 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 structure involved.

In any zoning district in which single-family dwellings are permitted, a single-family dwelling and customary accessory building may be erected on any single nonconforming lot if the lot is in separate ownership and not of continuous frontage with other lots in the same ownership (provided that yard dimensions and other requirements not involving lot area or lot width, or both, of the lot shall conform to the regulations for the zoning district in which such lot is located). This provision shall apply even though such lot fails to meet the requirements for lot area or lot width, or both, that are generally applicable in the zoning district. Variation of yard requirements shall be obtained only through action of the Zoning Hearing Board as provided for by § 1502(D), Variances.

If two or more nonconforming lots or combination of lots and portions of lots with continuous frontage are in single ownership, and if all or part of the lots do not meet the requirements for lot width and lot area established by this chapter, the lots involved shall be considered to be an undivided lot for the purposes of this chapter. No portion of said undivided lot shall be used or sold which does not meet lot width and lot area requirements established by this chapter, nor shall any division of the lot be made which leaves remaining any lot not meeting the requirements of this chapter. Any division of said lot containing a nonconforming use of a structure shall conform with the minimum lot area requirements for authorized uses.

Where, at the effective date of adoption of this chapter, a lawful use of lot exists that is made no longer permissible under the terms of this chapter as enacted or amended, such use may be sold or otherwise transferred to other owners, and may be continued as long as it remains otherwise lawful, subject to the following provisions:

No such structure may be enlarged or otherwise have any structure alterations made to it in a way which increases its nonconformity, except when the Zoning Hearing Board may determine undue hardship and may authorize a reasonable modification of such structure.

Any nonconforming structure which has been partially or completely damaged or destroyed by fire or other means may be rebuilt or repaired on its existing foundation even though such foundation may violate the setback requirements for the zoning district in which the structure is located, provided that the repair of reconstruction and reoccupancy of the structure occurs within 18 months of the date that the original structure was damaged or destroyed.

Should such structure be moved for any reason for any distance whatever, it shall thereafter conform to the requirements of the zoning district in which it is located.

In addition to the requirements of Article VII as they pertain to Floodplain Areas Overlay District, structures existing in any identified floodplain area prior to the date of adoption of restrictions in the identified floodplain area may continue provided that no expansion or enlargement of any existing structure shall be allowed within any identified floodway zoning district that would cause any increase in flood heights.

No existing structure devoted to a use not permitted by this chapter in the zoning district in which it is located shall be enlarged, extended, constructed, reconstructed, moved or otherwise have any structural alterations made to it except in changing the use of the structure to an authorized use in the zoning district in which it is located, unless the Zoning Hearing Board shall interpret that the enlargement, extension, construction, reconstruction or structural alteration is necessitated by the natural expansion and growth of trade of the nonconforming use.

Any nonconforming use may be extended throughout any part of a structure which was manifestly arranged or designed for such use at the time of adoption or amendment of this chapter, but no such use shall be extended to occupy any lot or portion of a lot outside such structure, except on a lot or portion of a lot owned at the use became nonconforming.

Any structure or structure and lot in combination in or on which a nonconforming use is superseded by an authorized use shall thereafter conform to the regulations for the zoning district in which such structure is located, and the nonconforming use may not thereafter be resumed.

When a nonconforming use of a structure or structure and lot in combination ceases for a period of more than 12 consecutive months, it shall be presumed that the nonconforming use has been abandoned, and any subsequent use of such structure or structure and lot in combination shall conform to the regulations specified by this chapter for the zoning district in which such lot is located.

Where nonconforming status applies to both the use and the structure on the lot, removal or destruction of the nonconforming structure shall eliminate the nonconforming use on the lot.

Nonconforming signs may be repairs or reconstructed, provided that no structural alterations are made which increase the gross surface area of the sign; however, nonconforming signs which are damaged or destroyed to an extent of more than 50% of their replacement cost at the time of destruction shall not be reconstructed except in conformity with the provisions of this chapter.

Nonconforming signs may not be enlarged, added to or replaced by another nonconforming sign, use or structure, except that interchange of poster panels shall be permitted.

The owner of a nonconforming use shall make an application for registration of the nonconforming use and, upon presentation of documentation acceptable to the Zoning Officer that the use was lawfully in existence prior to the effective date of this chapter or any amendment which created the nonconformity, the Zoning Officer shall register the same on a map and by Washington County deed and assessment registry block and lot number as a legal nonconforming use.

In the course of administering this chapter and reviewing applications for zoning certificates or variances, the Zoning Officer shall register all nonconforming structures as they become known through the application process.