Within the districts established by this Zoning Code, or by amendments thereto which may later be adopted, lots, uses of land, structures, and uses of structures and land in combination exist which were lawful before this Zoning Code was passed or amended, but which would be prohibited, regulated, or restricted under the terms of this Zoning Code. The legitimate interest of those who lawfully established these nonconformities are herein recognized by providing for their continuance, subject to regulations limiting their completion, restoration, reconstruction, extension, and substitution. Furthermore, nothing contained in this Zoning Code shall be construed to require any change in the layout, plans, construction, size, or use of any lot, structure, or structure and land in combination, for which a Zoning Permit became effective prior to the effective date of this Zoning Code, or any amendment thereto. Nevertheless, while it is the intent of this Zoning Code that such nonconformities be allowed to continue until removed, they should not be encouraged to survive. Therefore, no nonconformity may be moved, extended, altered, expanded, or used as grounds for any other use(s) or structure(s) prohibited elsewhere in the district without the approval of the BZA, except as otherwise specifically provided for in this Zoning Code.

   Nonconformities are declared by this Zoning Code to be incompatible with permitted uses in the districts in which such uses are located. A nonconforming use of a structure, a nonconforming use of land, or a nonconforming use of a structure and land in combination shall not be extended or enlarged after passage of this Zoning Code by attachment on a building or premises of additional signs intended to be seen from of the premises, or by the addition of other uses of a nature which would be generally prohibited in the district in which such use is located.

   To avoid undue hardship, nothing in this Zoning Code 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 Zoning Code and upon which actual building construction has been carried on diligently. Actual construction is hereby defined to include the placing of construction materials in a permanent position and fastened in a permanent manner. 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 the work shall be carried out diligently.

   In any district in which single-family dwellings are permitted, 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 Zoning Code, notwithstanding limitations imposed by other provisions of this Zoning Code. Such lot must 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 district, provided that yard dimensions and requirements other than those applying to area or width, or both, of the lot shall conform to the regulations for the district in which such lot is located. Variances of requirements listed in this Zoning Code, other than lot area or lot width, shall be obtained only through action of the BZA as described in Chapter 1143 Appeals and Variances.

   If two or more lots or a combination of lots and portions of lots with continuous frontage in single ownership are of record at the time of passage or amendment of this Zoning Code, and if all or part of the lots with no buildings do not meet the requirements established for lot width and area, the lands involved shall be considered to be an undivided parcel for the purposes of this Zoning Code, and 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 Zoning Code, nor shall any division of any parcel be made which creates a lot with a width or area below the requirements stated in this Zoning Code.

   Where, at the time of adoption of this Zoning Code, lawful uses of land exist which would not be permitted by the regulations imposed by this Zoning Code, the uses may be continued so long as they remain otherwise lawful, provided:

   Where a lawful structure exists at the effective date of adoption or amendment of this Zoning Code that could not be built under the terms of this Zoning Code by reason of restrictions on area, lot coverage, height, setbacks, yards, its location on the lot, bulk, or other requirements concerning the structure, such structure may be continued so long as it remains otherwise lawful, subject to the following provisions:

   If a lawful use involving individual structures, or if a structure and land in combination, exists at the effective date of adoption or amendment of this Zoning Code that would not be allowed in the district under the terms of this Zoning Code, the lawful use may be continued so long as it remains otherwise lawful, subject to the following provisions: