Any nonconforming use which existed at the time of the passage of this chapter may be continued, and any existing building designed, arranged, intended or devoted to a nonconforming use may be reconstructed or structurally altered, subject to the following regulations:
A. 
The structural alterations may be made in such buildings but shall in total not exceed 50% of the fair market value of the building unless the use thereof is changed to a conforming use. Such alterations shall not change the extent, the use or uses of the various portions of the premises, except that a conforming use may be extended at the expense of a nonconforming use.
B. 
No nonconforming use shall extend at the expense of a conforming use.
C. 
A nonconforming use shall not be changed unless changed to a conforming use. A nonconforming use changed to a conforming use may not hereafter be changed back to a nonconforming use.
D. 
No additions shall be permitted to the premises, including grounds and buildings, of any nonconforming use property, except such additions as shall be conforming.
Nothing herein contained shall require any change in the plan, construction or designated use of a building for which a building permit has been heretofore issued or plans for which are on file with the Building Inspector at the time of the passage of this chapter, and which entire building shall have been completed, according to such plans as filed, within one year from the date of the passage of this chapter.
Nothing in this chapter shall prevent the restoration of a building destroyed by fire, explosion, act of God or act of public enemy. Nothing in this chapter shall prevent the restoration of a wall declared unsafe by the Building Inspector.
[Added 7-7-2000]
A. 
Any nonconforming principal or accessory residential structure may be altered or enlarged without Land Use Board approval, provided that all of the following conditions are met:
[Amended 8-23-2012; 2-15-2018 by Ord. No. 18-04]
(1) 
Use of same is permitted in the district;
(2) 
Such alteration or enlargement does not create any new or additional encroachment or nonconformity;
(3) 
Such alteration or enlargement complies with all applicable development regulations as defined by this Zoning Code;
(4) 
Such alteration or improvement does not result in any vertical expansion above any existing nonconformity;
(5) 
Such alteration or improvement does not result in the closure or enclosure of any existing, open nonconformity, such as open deck; and
B. 
In any application where an addition, otherwise conforming, is proposed to a conforming structure located on a nonconforming lot, the Zoning Official may issue a building permit without referral to the Zoning Board of Adjustment.
[Amended 10-10-2002]