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 hereto may be continued except as follows:
A. 
Signs. Any sign which becomes nonconforming at the passage of this chapter or any applicable amendment shall be removed or altered so as to be in conformity within three years of the date of such passage.
B. 
Undeveloped subdivision lots. Any two or more adjoining undeveloped lots held by the same owner on the effective date of this chapter and whose area and/or width and/or depth are less than the specified minimum lot requirements and average density requirements of this chapter shall be resubdivided, if possible, to conform with the specified minimum requirements before a building permit may be granted.
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, or when required to do so by law, and except as follows:
A. 
Restoration and reconstruction. Any nonconforming use or structure damaged by fire, casualty or act of God may be repaired and used as before, provided that the floor area of such use, building or structure shall not exceed the floor area or building volume which existed prior to such damage. All repairs shall be completed within one year after damages occur or such use shall not be rebuilt except as a conforming use. In the event total destruction occurs or the Building Inspector orders said use or structure rebuilt, then the provisions of § 212-56 shall apply.
B. 
Repairs. Normal maintenance repair and incidental alteration of a structure containing a nonconforming use is permitted, provided it does not extend the area or volume of space occupied by the nonconforming use. A building or other structure containing residential nonconforming uses may be altered in any way to improve interior livability. No structural alterations shall be made which would increase the number of dwelling units.
C. 
Construction started prior to adoption of this chapter. Any building or structure, the construction of which has begun, pursuant to a valid building permit, prior to the effective date of this chapter or any applicable amendment thereto, may be completed and used in accordance with the approved plans and specifications for such building or structure.
D. 
Reconstruction. When a nonconforming use or structure is destroyed or damaged for a loss of 80% or more of its value, or when the owner or tenant of said use or structure desires to rebuild for any reason, the Zoning Board of Appeals, after review and recommendation by the Planning Board, may authorize such rebuilding if the rebuilding would not constitute a substantial enlargement of the use and if the rebuilding would provide better aesthetics, higher setbacks or assist in alleviating existing nuisance characteristics.
A nonconforming use shall be considered abandoned and the revival of such use shall not be permitted under the following circumstances:
A. 
Discontinuance of use. If such nonconforming use shall be discontinued for more than 180 consecutive days; or
B. 
Change to permitted use. If such nonconforming use be changed to a permitted use; or
C. 
Change to more conforming use. If such nonconforming use be changed to a use more nearly in conformity with the regulations for the zoning district in which it is located.
A. 
Existing undersized lots.
(1) 
Any lot held in single and separate ownership prior to the adoption of this chapter and whose area and/or width and/or depth are less than the specified minimum lot requirements in this chapter for that zoning district, may be considered as complying with such minimum lot requirements and no variance shall be required, provided that:
(a) 
Such lot does not adjoin any other lot or lots held by the same owner whose aggregate area is equal to or greater than the minimum lot area required for that district;
(b) 
Such lot has an area of at least 5,000 square feet and a minimum width of at least 50 feet at the required setback line if it is to be used for residential purposes;
(c) 
The following minimum yard dimensions are maintained for residences:
[1] 
Side yards: 8 feet;
[2] 
Front and rear yards: 25 feet; and
(d) 
All other bulk requirements for that district are complied with.
(2) 
In any zoning district where residences are permitted, such undersized nonconforming lots may be used for not more than one single-family dwelling.
(3) 
A lot of nonconforming size may be subdivided if each and every subdivision of such lot is purchased by the owner or owners of the adjoining properties to increase the size of said owner's or owners' property or properties.
B. 
Reduction in lot area. No lot shall be so reduced in area as to create a nonconforming bulk or use in violation of any of the regulations contained in this chapter.