Except as otherwise provided herein, this By-law shall not apply to structures or uses lawfully in existence or lawfully begun, or to a building permit or special permit issued, before the first publication of notice of the public hearing on this By-law required by G.L. c. 40A, §5. However, this By-law shall apply to the following:

Preexisting nonconforming structures or uses may be extended or altered; provided, that no extension or alteration shall be permitted unless there is a finding by the Board of Appeals that the change, extension, or alteration shall not be substantially more detrimental to the neighborhood than the existing nonconforming structure or use. It is the purpose of this By-law to discourage the perpetuity of nonconforming structures and uses whenever possible.

Construction or operations under a building permit or special permit shall conform to any subsequent amendments of this By-law unless the use or construction is commenced within a period of 12 months after the issuance of the permit and in cases involving construction, unless such construction is continued through to completion continuously and expeditiously as is reasonable.

Anything to the contrary in this By-law notwithstanding, the residential use of two or more dwellings on a single lot shall be deemed a preexisting nonconforming use if commenced prior to March 25, 1958. This use may only be altered, extended, or modified by special permit pursuant to this section provided the Board of Appeals finds through a preponderance of credible evidence that the use commenced prior to March 25, 1958, and has not been abandoned or not used for a period of two years or more. In approving any alteration, extension, or modification, the Board of Appeals shall require that the number of dwelling units be limited to the same as in existence on March 25, 1958.

Any residential structure in existence as of January 1, 1970, not protected by this By-law will be deemed to be conforming to the dimensional requirements of this By-law, but any alteration, reconstruction, extension, or structural change shall conform to the current By-law dimensional requirements.

Single-Family or Two-Family Dwellings.

Nonconforming Structures Other Than Single-Family or Two-Family Dwellings. Except as provided elsewhere in this By-law, the following provisions shall apply to nonconforming structures other than single-family or two-family dwellings:

Nonconforming Structures in Existence; Enforcement.

Unsafe Structures. Any nonconforming structure that has not been abandoned and is determined to be unsafe may be restored to a safe condition, provided such work on the structure shall be completed within two years of the determination that the structure is unsafe and it shall not place the structure in greater nonconformity. The Board of Appeals may by special permit waive this condition or extend the completion period.

A nonconforming use, except for agriculture, horticulture, or floriculture, as defined in G.L. c. 128, §1A, of any open space on a lot outside a structure, or of a lot not occupied by a structure, shall not be extended.

A nonconforming principal use of a structure shall not be extended. However, any nonconforming use of structure may be changed to another nonconforming use by special permit provided the Board of Appeals finds that the new use is not a substantially different use and not more detrimental to the neighborhood than the existing use.

A nonconforming accessory use of a portion of a structure or any conforming accessory use of a portion of a nonconforming structure may be extended up to a maximum of 40 percent of the floor area of the existing structure.

A nonconforming use which has been changed to a permitted use shall not again be changed to another nonconforming use.

Any lot, or open space on a lot, including yards and setbacks, shall not be reduced or changed in area or shape such that the lot, open space, yard, or setback is made nonconforming or more nonconforming unless a special permit has been granted under the provisions of this By-law. However, this Section 6.4 shall not apply in the case of a lot a portion of which is taken for a public purpose.

A nonconforming lot which has come into conformity shall not again be changed to a nonconforming lot.

Any off-street parking or loading spaces, if already equal to or less than the number required to serve their intended use, shall not be further reduced in number except as provided in Section 7.1.

Reconstruction of a legally nonconforming structure damaged or destroyed by fire or other accidental or natural cause shall be allowed if the reconstruction is substantially in the form it had at the time of damage or destruction, or in any form if within applicable setback requirements and not larger than previously, and if reconstruction is started within 24 months and completed within 36 months of the damage or destruction.

A nonconforming use shall be considered abandoned when the premises have been devoted to another use, or when the characteristic equipment and the furnishing of the nonconforming use have been removed from the premises and have not been replaced by similar equipment within two years unless other facts show intention to resume the nonconforming use.

A nonconforming use or structure that has been abandoned, demolished without reconstruction, or not used for a period of two years or more shall lose its protected status and shall be subject to all provisions of this By-law; however, the Planning Board may grant a special permit to authorize the reestablishment of a nonconforming use or structure where such reestablishment shall not result in substantial detriment to the neighborhood. The Planning Board shall consider the lot size, the existing building coverage, and available on-site parking based upon review of the specific characteristics of the site, including, but not limited to, available area, traffic patterns, access to public ways, intended use of the site, and protection of public safety and convenience, except that any use so allowed shall not be more substantially detrimental to the neighborhood than the previous use.

Any nonconforming use that has either been abandoned or that has not been used for two years or more shall lose the protections accorded under this By-law and shall be required to conform to the current By-law.

A nonconforming structure determined by the Zoning Enforcement Officer to be unsafe may be restored to a safe condition, provided such work on any nonconforming structure shall be completed within one year of the determination that the structure is unsafe and it shall not place the structure in greater nonconformity. The Board of Appeals may by special permit extend the completion period.

Alteration, reconstruction, extension, or structural change (collectively "alteration") of a nonconforming single- or two-family residential structure shall not be considered an increase in the nonconforming nature of the structure and shall be permitted as of right under the following circumstances:

Interior alteration of any otherwise conforming structure that does not change the nature of, nor increase the intensity of, a nonconforming use, and interior alterations of preexisting nonconforming structures for a use or uses which are otherwise allowed by zoning.

Reconstruction of a legally nonconforming structure damaged or destroyed by fire or other accidental or natural cause, other than flood damage sustained to structure within any floodplain shown on the flood insurance rate maps of Southbridge, if the reconstruction is substantially the form it had at the time of damage or destruction, or in any form if within applicable setback requirements and not larger than previously, and if reconstruction is started within 24 months and completed within 36 months of the damage or destruction.

Nonconforming uses and structures in the Watershed Protection District may be extended or altered through the issuance of a special permit by the Planning Board upon a finding that such extension or alteration shall not be substantially more detrimental to the water supply than the existing use. A nonconforming use shall not be changed to another nonconforming use.

Reconstruction of any permitted commercial accommodation structure or unit(s), if for the purpose of rehabilitation or upgrade, and if the commercial accommodation was licensed and operational for the three years prior to the rehabilitation or upgrade. The reconstruction shall not allow rebuilding at a greater density, greater height, or at a different location than previously existed.

Not exempted under this section are accessory uses and structures.