Except as otherwise provided in this article, the lawful use of land or buildings existing at the date of the adoption of this chapter may be continued although such use or building does not conform to the regulations specified by this chapter for the zone in which such land or building is located; provided, however, that no nonconforming lot shall be further reduced in size.

Lots which do not meet the minimum area requirements of the Zoning Ordinance, which are currently in use as of the date of adoption of this chapter, may continue in that use unless and until the building located thereon is substantially destroyed by fire or other causes, including acts of the owner, and thereafter no such structure shall be rebuilt except in conformance with provisions in this chapter.

If a nonconforming building or use is subsequently changed to a conforming use, it shall not again be occupied or used except in conformity with the requirements of the districts wherein such building or use is located.

A nonconforming building may be reconstructed or structurally altered so long as the work performed does not constitute a substantial reconstruction or alteration of the building as existing on the effective date of this chapter, provided that no nonconforming use is extended or changed to another nonconforming use.

If any principle structure is nonconforming as of the date of the adoption of this amendment in that it violates setback or height requirements, additions or alterations may be added so long as the additions or alternations are in conformance with current height, lot coverage and setback requirements. Such an addition or alteration shall be permitted to be made without the necessity of obtaining variance.

Whenever the boundaries of a district shall be changed so as to transfer an area from one district to another of a different classification, the foregoing provisions shall also apply to any nonconforming uses existing therein or created thereby. (Original Section 605, relating to permits issued prior to the adoption of the ordinance appearing in this chapter, which immediately followed this section, was deleted at time of adoption of Code; see Ch. 1, General Provisions, Art. I.)