The structural alterations made in such buildings shall in no case exceed 50% of the true value of the buildings, nor shall the building be enlarged, unless the use therein is changed to a conforming use; provided, however, that where a building meets the use requirements of this chapter and is nonconforming because of height and area regulations, structural alterations made in such buildings may exceed 50% of the true value, provided the height and area requirements are not further violated.

A nonconforming use changed to a conforming use may not hereafter be changed back to a nonconforming use.

A structure or use of land which is nonconforming in use shall not be enlarged or extended except as provided under this chapter. A building or use of land which is nonconforming in a manner other than use may be extended or enlarged provided that the nonconformance is not further increased.

Nothing in this chapter shall require any change in plans, construction or designated use of a structure for which a building permit has been heretofore issued when construction has been diligently prosecuted and completed within one year of the effective date of this chapter.

Nothing in this chapter shall be interpreted as authorization for or approval of the continuance of the use of a structure or premises in violation of zoning regulations in effect the time of the effective date of this chapter.

Normal maintenance and repair of a structure containing a nonconforming use is permitted, provided that it does not extend the area or volume of space occupied by the nonconforming use and does not increase the number of dwelling units.

Nothing in this chapter shall prevent the strengthening or restoring to a safe or lawful condition any part of any building or structure declared unsafe or unlawful by the Construction Official and/or other authorized state or Borough official.

Any existing single-family residential dwelling with a permitted use located on a conforming lot which violates any yard requirements may have additions to the principal building and/or construct an accessory building without an appeal for a variance, provided the total permitted building coverage is not exceeded and the accessory building and/or addition does not violate any requirements of this chapter or exacerbate any existing or nonconforming yard requirement.

Any preexisting nonconforming two-family residential dwelling located on a conforming lot may construct one deck with a deck floor elevation not higher than the floor elevation of the first floor dwelling without an appeal for a variance; provided that (1) the permitted building coverage is not exceeded; (2) all yard and setback requirements are complied with; (3) the deck shall be constructed of a material and in such a manner that shall allow water to pass through the floor of said deck; (4) that said deck shall be open to the elements beneath the floor; and (5) that there shall be no roof over the deck.

A nonconforming use shall be considered abandoned if it is terminated by the owner, if a nonconforming use involving a structure is discontinued for 12 consecutive months, or if a nonconforming use of land without structure(s) ceases for a period of six months. The subsequent use of the abandoned structure and/or land shall be in conformity with this chapter.