A use, building or structure lawfully in existence at the effective date of this chapter, which shall be made nonconforming at the passage of this chapter or any applicable amendment thereto, mad be continued except as otherwise provided in this article.

No existing building or premises devoted to a nonconforming use shall be enlarged, extended, reconstructed, substituted or structurally altered except when changed to a conforming use, when required to do so by law, or as permitted in § 126-365.

Structures and their uses that are nonconforming may be continued so long as they otherwise remain lawful but shall not be enlarged, expanded or altered except to become more in conformity. Any replacement of a nonconforming structure shall conform to this chapter. Any nonconforming structure destroyed to an extent greater than 50% of its assessed valuation shall not be reconstructed except in conformity with this chapter, unless provided for in § 126-361 below. If located in a floodway, any nonconforming use or structure partially damaged by fire, flood, casualty or act of God shall be terminated. Changes from one nonconforming use to another is prohibited.

Nothing in this chapter shall prevent the restoration or continuance of a nonconforming accessory structure which is nonconforming because it fails to comply with height, area, yard or other like requirements of this chapter and which is destroyed to an extent greater than 50% of its assessed valuation, provided that any restoration of any such accessory structure shall not enlarge the previously existing nonconformance.

Normal maintenance and repair of a nonconforming structure or use is permitted, provided it does not extend or expand the nonconformance.

A nonconforming nonseasonal use not used for six consecutive months and/or the change of use to a more restricted or conforming use for any period of time shall be considered a termination of the nonconforming use, and such nonconforming use shall not thereafter be revived.

Any nonconforming structure or use lawfully under construction on the effective date of this chapter pursuant to plans filed with the Building Inspector and approved by him and all other municipal boards and agencies as required under law may be completed and may be used for the nonconforming use for which it was designed, to the same extent as if such building had been completed and was in use on the effective date of this chapter.

A nonconforming residential use or structure may be expanded to provide additional living space, provided the expansion does not increase the maximum number of dwelling units permitted in the zone and does not infringe further upon any nonconforming side, front or rear yard. However, no additional building exteriors shall be closer than five feet to any side lot line.