This Zoning Bylaw or any amendment thereto shall not apply to the use of any structure or land uses lawfully in existence or lawfully begun, or to a building or special permit issued before the first publication of notice of the public hearing on such bylaw required by MGL c. 40A, § 5, as amended, but shall apply to any change or substantial extension of such use, to a building or special permit issued after the first notice of said public hearing, to any reconstruction, extension or structural change of such structure and to any alteration of a structure begun after the first notice of said public hearing to provide for its use for a substantially different purpose or for the same purpose in a substantially different manner or to a substantially greater extent except where alteration, reconstruction, extension or structural change to a single- or two-family residential structure does not increase the nonconforming nature of said structure.
A. Preexisting nonconforming uses or structures (extensions).
(1) This section shall not apply to billboards, signs and other advertising devices subject to the provisions of MGL c. 93, §§ 29 through 33, inclusive, or MGL c. 93D.
(2) The Zoning Board of Appeals, by special permit, may authorize lawfully preexisting, nonconforming uses or structures to be changed or altered, provided that such extension, alteration or enlargement meets all the following requirements:
(a) All the special permit guidelines of § 2.3C;
(b) That it will not be substantially more detrimental or objectionable to the neighborhood than the existing nonconforming structure or use to the neighborhood.
B. Building construction and special permits. Construction or operations under a building or special permit obtained in conformity with this Zoning Bylaw, or lawful amendments thereto, shall conform to any subsequent amendments of the Zoning Bylaw unless the use or construction is commenced within a period of not more than 12 months after the issuance of such permit and, in cases involving construction, unless such construction is continued through to completion as continuously and expeditiously as is reasonable.
C. Nonconforming single- and two-family residential structures. Nonconforming single- and two-family residential structures may be reconstructed, extended, altered, or structurally changed upon a determination by the Building Commissioner that such proposed reconstruction, extension, alteration, or change does not increase the nonconforming nature of said structure. The aggregate sum of the gross floor area of all additions to a structure since the date when the structure became nonconforming under the provisions of this subsection shall not be greater than 50% of the gross floor area of the dwelling unit or 1,000 square feet, whichever is smaller, unless a special permit is issued by the Zoning Board of Appeals under § 5.2A allowing a larger gross floor area. The following circumstances shall not be deemed to increase the nonconforming nature of said structure:
(1) Alteration to a structure which complies with all current setback, yard, building coverage, and building height requirements but is located on a lot with insufficient area, where the alteration will also comply with all of said current requirements.
(2) Alteration to a structure which complies with all current setback, yard, building coverage, and building height requirements but is located on a lot with insufficient frontage, where the alteration will also comply with all of said requirements.
(3) Alteration to a structure which encroaches upon one or more required yard or setback areas, where the alteration will comply with all current setback, yard, building coverage and building height requirements; the provisions of this subsection shall apply regardless of whether the lot complies with current area and frontage requirements.
(4) Alteration to the side, front or rear of a structure which encroaches upon a required yard or setback area, where the alteration will not encroach upon such area to a distance greater than the existing structure; the provisions of this subsection shall apply regardless of whether the lot complies with the current area and frontage requirements.
D. Notwithstanding § 5.2C, in the event that the Building Commissioner determines that the nonconforming nature of such structure would be increased by the proposed reconstruction, extension, alteration, or change, the Zoning Board of Appeals may, by special permit, allow such reconstruction, extension, alteration, or change where the proposed modification will not be substantially more detrimental than the existing nonconforming structure to the neighborhood.
E. Preexisting nonconforming use. Any increase in the area or extent of the nonconforming use of a structure or land made by special permit from the SPGA is limited to a 50% increase in the nonconforming floor area or land area at the time the use became nonconforming.
F. Abandonment. A nonconforming use which has been abandoned or discontinued for a period of two years shall not be reestablished and any future use shall conform with this bylaw, except in the case of land used for agriculture, horticulture or floriculture where such nonuse shall have existed for a period of five consecutive years.
G. Restoration. Any nonconforming building or structure in existence at the time of adoption of this bylaw or any amendment thereto may be reconstructed on the old foundation area if destroyed by fire or other accidental or natural cause, provided such reconstruction takes place within a period of two years (six months in the case of nonconforming signs) from the date of catastrophe, or else such reconstruction must comply with this bylaw.
H. Changes. Premises may be changed from one nonconforming use to another only on special permit from the SPGA. Such permit shall be granted only for uses whose externally observable attributes are no more damaging to or inharmonious with the environs than those of the use being replaced. See § 5.2A(2) for additional criteria for the granting of special permit hereunder.