In any district in which single-family dwellings are permitted, notwithstanding limitations imposed by other provisions of this chapter, a single-family dwelling and customary accessory buildings may be erected on any single lot of record at the effective date of adoption or amendment of this chapter. Such lot shall be in separate 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 district, provided that yard dimensions and other requirements not involving area or width, or both, of the lot shall conform to the regulations for the district in which such lot is located. Variance of area, width, yard and coverage requirements shall be obtained only through action of the Zoning Hearing Board, except that the Zoning and Code Management Officer may grant approval for a building permit where the area of the lot to receive the new construction and/or the proposed distances from the new construction to front, side or rear lot lines does not exceed 20% less than the minimum requirements for the zone district in which the lot is located, and such grant of approval is reasonable considering the lot and the proposed structure to be built upon it.

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, and if all or part of the lots do not meet the requirements for lot width and area as established by this chapter, the lands involved shall be considered to be an undivided parcel for the purposes of this chapter, and no portion of the 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 extended to occupy a greater area of land than was occupied 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 two years, any subsequent use of such land shall conform to the regulations specified by this chapter for the district in which such land is located.

No such structure may be enlarged or altered in any way which increases its nonconformity unless an enlargement or structural alteration makes the building more conforming or is required by law.

Structures that have been destroyed or damaged may be rebuilt or repaired on their foundations even though such foundation may violate the setback requirements for the zone district where the structure is located and even though the use to be continued in the rebuilt structure is not permitted in the zone district, provided that the rebuilding or repair and reoccupancy of the structure occurs within two years of the date that the original structure was destroyed or damaged.

Should such structure be moved for any reason, it shall thereafter conform to the regulations for the district in which it is located after it is moved.

Structural alterations may be permitted if necessary to adapt a nonconforming building to new technologies or equipment pertaining to uses housed in such building. Any enlargement necessary to adapt to new technologies shall be authorized only by a variance, issued by the Zoning Hearing Board.

No existing structure devoted to a use not permitted by this chapter in the district in which it is located shall be enlarged, extended, constructed, reconstructed, moved or structurally altered except in changing the use of the structure to a use permitted in the district in which it is located.

Any nonconforming use may be extended throughout any parts of a building 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 land outside such building.

If no structural alterations are made, any nonconforming use of a structure or structure and land in combination may be changed to another nonconforming use, provided that the Zoning Hearing Board, 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 district than the existing nonconforming use. In permitting such change, the Zoning Hearing Board may require appropriate conditions and safeguards in accord with the provisions of this chapter.

Any structure, or structure and land in combination, in or on which a nonconforming use is superseded by a permitted use, shall thereafter conform to the regulations for the 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 premises in combination, is discontinued or abandoned for two years, the structure, or structure and premises in combination, shall not thereafter be used except in conformance with the regulations of the district in which it is located.

Where nonconforming use status applies to a structure and premises in combination, removal or destruction of the structure shall eliminate the nonconforming status of the land.

Nothing in this article shall be deemed to prevent the strengthening or restoring to a safe condition of any building or part thereof or remodeling of interior spaces or exterior surfaces so long as the nonconforming aspects of the use and/or structure are not increased.

As to one- and two-family dwellings which constitute nonconforming uses within the C-1, the C-2, the M-1 and the M-2 Zoning Districts, nothing in this article shall be deemed to prevent the alteration (as defined in § 260-7) of the one- or two-family dwelling or the addition of an accessory structure, including sheds, garages or other customary accessory structures for one- and two-family dwellings, subject to development standards set forth in the R-3 Zoning District.