The lawful use of any building or land existing at the time of the enactment of this chapter may be continued although such use does not conform with the provisions of this chapter.

A nonconforming use shall not be enlarged and the buildings or premises shall not be reconstructed or structurally altered, without the issuance of a permit by the Zoning Board of Appeals, and unless the altered or enlarged portion shall be changed to conforming use, and once so changed, shall not be changed back to a nonconforming use.

Any structure destroyed by fire or other calamity may be restored within 12 months of such destruction and the former use continued, provided that the reconstruction shall not exceed the dimensions of the destroyed property.

Nothing in this chapter shall prevent the replacement of any structural member to insure the safety of a building.

Whenever a nonconforming use has been discontinued for a period of one year, the use shall not thereafter be reestablished, and any future use shall be in conformity with the provisions of this chapter.

Any mobile home that replaces a nonconforming mobile home must carry a 1976 or later Federal HUD data plate and conform to New York State Uniform Fire and Building Code Standards (as stated in Article III, 12.20, 12.21, 12.22, and 12.23 of those standards). The skirting must be installed within 60 days with wood, cement, metal, rigid plastic, or factory-approved materials. Each entrance should have proper stairs and footing in accordance with New York State Uniform Fire and Building Code standards (as stated in Article III of those standards).