Within the zoning districts established by this chapter or subsequent amendments thereto, there may exist certain nonconformities which, if lawful prior to the adoption or amendment of this chapter, may be continued, subject to certain limitations, under the terms of this chapter or subsequent amendments thereto.

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 or structure on which actual construction was lawfully begun prior to the effective date of this chapter or any amendment thereto, and has been diligently carried on.

In any district wherein a single-family dwelling is a permitted use, a single-family dwelling and customary accessory buildings may be erected on any single lot of record legally existing at the effective date of this chapter or of any amendment hereto, notwithstanding limitations imposed by other provisions of this chapter. This provision shall apply even though such lot fails to meet the requirements for area and/or width which are generally applicable in the district, provided that other yard requirements conform to the regulations for the district in which such lot is located.

If two or more lots, or combination(s) thereof, in single ownership are recorded prior to the effective date of this chapter, and if each of said lots, taken individually, does not comply with this chapter, but a combination thereof does comply, such combination shall be considered a single, undivided parcel for the purposes of this chapter. No portion of said parcel shall be used or sold in a manner which diminishes compliance with lot width and area requirements established by this chapter, nor shall any division of any parcel be made which creates a lot with width or area less than the minimum required by the provisions of this chapter.

Extension. No such nonconforming use shall be enlarged or increased, nor extended to occupy a greater area of land than was owned or leased by the user at the effective date of this chapter.

Discontinuance. When a nonconforming use has been discontinued or abandoned for 12 consecutive months, such nonconforming use shall not thereafter be resumed. Any future use shall be in conformity with the provisions of this chapter.

Changes of use.

Additional structures or buildings. No additional structure(s) or building(s) not in conformity with the requirements of this chapter shall be erected in connection with a nonconforming use of land.

Enlargement. A nonconforming structure or building may be enlarged or increased by not more than 25% of its gross floor area as of the effective date of this chapter.

Damage or destruction. A nonconforming structure which is destroyed or partially destroyed by fire, explosion, or by any means to an extent of 75% or more of its market value (as estimated immediately prior to such damage or destruction) shall not be repaired or restored to a nonconforming status, but shall either be removed from the site entirely or restored as a conforming structure.

Moving of a structure. A nonconforming structure shall not be moved, unless it is sited in conformance with all applicable regulations of the zoning district to which it is moved.

Discontinuance. Whenever a nonconforming structure or building has been vacated for a period of 12 consecutive months, such structure or building shall thereafter not be used except in conformance with the provisions of this chapter.

Extension. A nonconforming use may be extended throughout any part of an existing structure or building, provided that any structural alterations, extensions, or additions comply with all provisions of this chapter with respect to height, area, width, yard area, and lot coverage specified for the zoning district within which the building or structure is located. However, such extension of a nonconforming use shall not exceed 50% of the gross floor area occupied by said nonconforming use at the time such nonconforming use became nonconforming.

Change of use. A nonconforming use, if changed to a conforming use, shall not thereafter be changed back to any nonconforming use. A nonconforming use may, as a use by special exception, be changed to another nonconforming use, provided that the Zoning Hearing Board shall find that the proposed use is equally appropriate or more appropriate in the zoning district than the existing nonconforming use.

Discontinuance. Whenever a nonconforming use of a structure or building or portion thereof has been discontinued or abandoned for 12 consecutive months, such structure or building or part thereof shall not thereafter be used for a nonconforming use.

Destruction. Removal or destruction of the structure or building shall eliminate the use of the land upon which the structure or building was erected for a nonconforming use. For the purposes of this subsection, "destruction" is defined as damage to an extent of 75% or more of the market value of the structure or building immediately prior to such damage or destruction.