Except as otherwise provided in this chapter, the lawfully permitted use of land or buildings existing at the time of the adoption of or any amendment to this chapter may be continued although such use does not conform to the regulations specified by this chapter for the district in which such land or building is located. Said uses shall be deemed nonconforming uses.

Where no building is involved, the nonconforming use of land may be continued; provided, however, that no such nonconforming use shall be enlarged or increased nor shall it be extended to occupy a greater area of land than that lawfully occupied by such use at the time it became legally nonconforming nor shall any such nonconforming use be moved, in whole or in part, to any other portion of the lot or parcel of land occupied by such nonconforming use at the time of the adoption of the provisions of this chapter that made it nonconforming, provided, further, that if such nonconforming use of land or any portion thereof ceases for any reason for any continuous period of more than 90 days or is changed to a conforming use, any future use of the land shall be in conformity with the provisions of this chapter. No nonconforming use of land shall be changed to another nonconforming use.

A building that is conforming in use but does not meet the height, yard, court, floor area, parking, loading, open space or land coverage requirements of this chapter shall not be considered to be nonconforming within the meaning of § 240-68. However, no permit shall be issued that will result in an increase in the extent by which such building fails to meet such requirements.

If any building shall be accidentally destroyed or damaged due to fire, explosion or other cause to the extent of not more than 50%, above the foundations, of its reproduction value at the time of the damage, as determined by the Building Inspector or the Director of Building Code Enforcement and Land Use Administration, it may be restored on its original foundations, but if damaged or destroyed to a greater extent, it nevertheless may be rebuilt or restored to provide an equivalent livable or usable area, but it shall conform to the side yard requirements in this chapter, and if such building shall be a dwelling, it shall not be nearer to the street than the average distance of the dwellings on the lots adjacent thereto on each side or, if there be none adjacent, the average of the two nearest dwellings on the same side of the street in the same block, provided that such buildings, when restored, shall comply with the structural requirements of Chapter 106, Fire Prevention and Building Construction. This section shall not apply unless such building is restored within 12 months of such damage or destruction.

Any building for which a permit has been duly granted prior to the effective date of any amendment to this chapter which makes such building nonconforming as to use or causes it to deviate in other respects from the height, yard, court, floor area, parking, loading, open space or land coverage requirements of this chapter may be completed in accordance with the plans on file with the Building Inspector or the Director of Building Code Enforcement and Land Use Administration, subject, however, to the provisions of § 240-87 of this chapter.

Any use lawfully existing on the effective date of this amended chapter or on the date of any subsequent amendment to this chapter, in the district in which such use is or was at that time classified in this chapter as one requiring a special permit, shall, without further action, be deemed to be a conforming use in such district. Any extension of or addition to such use or any enlargement or extension of any building or structure shall be subject to the requirements of §§ 240-60 through 240-64, inclusive, of this chapter, and said sections shall apply to such extension, addition or enlargement of any use, building or structure in like manner as to original permitted special uses.