Any structure or use of land which is nonconforming because of use shall not be enlarged or extended in any manner whatsoever.

There shall be no structural alterations made to any nonconforming building or structure that is nonconforming because of use. Structural alterations may be made in a building which is nonconforming because it fails to comply with height, area, yard, off-street parking or other like requirements of this chapter, so long as the structural alteration does not extend or enlarge the nonconformance. This shall be construed to mean the structural alteration shall comply with all use, height, yards, off-street parking requirements, and all other provisions of this chapter.

A nonconforming use changed or altered to a conforming use may not thereafter be changed back to a nonconforming use, but nothing hereinbefore stated shall prevent the strengthening or restoring to a safe and lawful condition of any part of any building declared unsafe by the Construction Official, the Chief of the Borough Fire Department or the Borough Engineer.

In the event that there shall be cessation of operation of any nonconforming use for a period of 12 consecutive calendar months, the same shall be presumed an abandonment of such nonconforming use. Any subsequent attempt to rely upon, exercise or reinstate such abandonment of nonconforming use (the provisions of subsection 34-11.1 notwithstanding) shall be deemed a violation of the terms of this chapter.

Nothing in this chapter shall require any change in plans, construction or designated use of a structure or building for which a Building Permit has been heretofore validly issued or if a variance has been authorized by the Board of Adjustment or if construction has been started and diligently prosecuted at the time of the adoption of this chapter.

Nothing in this chapter shall be construed as authorization for or approval of the continuance of the use of a building, structure or premises in violation of any zoning ordinances, rules or regulations in effect immediately preceding the time of the effective date of this chapter unless made conforming by the enactment of this chapter.

Any nonconforming use that is nonconforming because it fails to comply with height, area, yard, off-street parking or other like requirements of this chapter, shall not be changed or altered to enlarge the nonconformance.