In any district, a permitted use may be constructed on a lot which does not conform to minimum lot area and/or minimum lot width and lot depth requirements for the use, if the lot existed on the effective date of these regulations or on the date of any amendment of these regulations and such adoption or amendment renders such lot a nonconforming lot, further provided that:
A. 
If the owner of said nonconforming lot owns any adjoining undeveloped lot(s), the nonconforming lot shall be joined with all or subdivided portions of such adjoining lot(s) to create a conforming lot or to mitigate the nonconforming condition.
B. 
Any use constructed on a nonconforming lot shall have yard depths conforming to the minimum requirements of the district in which located.
Except as otherwise provided herein, the lawful use of any land, buildings and other structures which existed on the effective date of these regulations may be continued whether or not conforming to these regulations.
Any use which does not conform to these regulations or which becomes nonconforming as a result of any amendment of these regulations may only be modified as follows:
A. 
Except as otherwise provided herein, nonconforming structures may continue to exist and to be maintained and repaired.
B. 
Alterations or additions to a nonconforming structure may be made upon approval by the Planning Board and issuance of a building permit only to the extent that such alterations or additions do not significantly increase the impact of the nonconformity on adjoining lots, and only to the extent that any nonconforming use related to such structure is not significantly expanded. In general, and by way of illustration and not exclusion, an extension of a portion of a structure which maintains an existing nonconforming yard depth may be approved by the Planning Board, but an extension which further reduces an existing nonconforming yard depth may not be approved by the Planning Board.
C. 
Nonconforming structures may be repaired and restored to their former condition after damage by fire or other casualty loss, provided that the nonconformity shall not be increased, and that construction shall commence within two years of the casualty loss. After the expiration of this period, the structure may only be repaired or restored to a conforming condition.
D. 
A nonconforming use may not be enlarged to occupy additional existing floor area within an existing nonconforming or conforming structure or additional lot area.
E. 
A nonconforming use, if changed to a conforming use, shall not subsequently be changed back to a nonconforming use.
F. 
A nonconforming use of a structure shall generally not be changed to another nonconforming use. However, upon application, the Planning Board may grant a waiver for a change to a comparable or more restrictive use classification upon a finding by the Planning Board that the proposed nonconforming use will have a lesser impact on surrounding properties than the existing nonconforming use. In its determination, the Planning Board shall consider parking demand, pedestrian and vehicular traffic volume, intensity of use, hours of activity, noise levels, whether the existing nonconforming condition may have resulted from an amendment of these regulations, and any other factors it considers to be relevant under the circumstances. The Planning Board shall have absolute discretion in this matter, and nothing herein is intended to afford any special status or rights to a change from one nonconforming use to another nonconforming use. The Board may elect to hold a public hearing on such a change.
G. 
Any nonconforming use of a structure or land which has ceased for a period of one year shall be deemed abandoned and may not be resumed, and thereafter such structure or land shall be used only in conformity with these regulations. The provisions of Subsection F above shall not be applicable with respect to an abandoned nonconforming use.
H. 
No modification of a structure, whether an addition or an internal renovation, which increases the floor area devoted to an otherwise conforming use shall be made if such modification introduces or increases the degree of nonconformity with respect to off-street parking requirements.
I. 
Nothing herein shall require any modification in use, alteration or other construction involving a nonconforming structure for which a building permit has been issued.