A. 
The Board of Appeals, established by Article 43 of this Bylaw, is hereby designated as Special Permit granting authority.
B. 
Any person or persons desiring to construct and use, or to alter, enlarge, reconstruct and use, any building or structure for any purpose for which permission of the Board of Appeals is required, shall make application in writing therefor to said Board, which shall within a reasonable time hold a public hearing thereon, 14 days public notice of which shall be given at the expense of the applicant, together with such other notice to adjoining owners and others, as the said Board of Appeals shall order, or by regulation prescribed, including posting a copy of the notice in a conspicuous location upon the property to which said application relates.
C. 
Special permits shall be issued only after a public hearing held within 65 days after filing of an application with the Board of Appeals. The Board of Appeals shall act on Special Permit requests within 90 days after the public hearing. The Board of Appeals shall consider possible detrimental effects upon a neighborhood in determining whether to grant a special permit.
D. 
At said hearing or as soon as may be thereafter, the Board of Appeals shall expressly find and determine:
(1) 
If permission is sought to use a building or structure for a use incidental to or usual in connection with a purpose permitted by any section of this Bylaw, whether such use is in fact incidental to or usual in connection therewith.
(2) 
Whether the use of a building or structure, for the purposes for which permission is sought, is or would be in violation of any specific provision of this Bylaw, or would prove to have any nuisance qualities, or be for any reason injurious to the health, safety, morals, or welfare of the community in any of the districts zoned under this Bylaw.
E. 
As soon as may be after the hearing, the Board of Appeals shall adopt an order, notice of which shall be given to the petitioner and any persons who have appeared at the hearing, which shall embody their findings, and grant or refuse the permission applied for, in accordance with such findings.
F. 
Unless otherwise specified, a Special Permit granted under this Bylaw shall lapse in two years, not including time required to pursue or await the determination of an appeal referred to in MGL Chapter 40A, Section 17, as amended, from the grant thereof, if a substantial use thereof has not commenced except for good cause or, in the case of permit for construction, if construction has not begun by such date except for good cause.
G. 
Construction or operations under a Building or Special Permit shall conform to any subsequent amendment of the zoning by-law unless the use or construction is commenced within a six-month period after the issuance of the permit and in cases involving construction, unless such construction is continued through to completion as continuously and expeditiously as is reasonable.
In addition to the permission required by the Board under other sections of this Bylaw, the Board of Appeals may also grant:
A. 
A permit for the extension of an existing non-conforming building, either within the same district or into a more restricted district, all under such conditions as will safeguard the character of both districts. This shall not apply where alteration, reconstruction, extension, or structural change to a single or two-family residential structure does not increase the non-conforming nature of said structure.
B. 
Uses accessory to activities that are necessary for scientific research, scientific development or related production allowed by right, whether or not on the same parcel as said scientific activities, may be allowed by Special Permit provided the Board of Appeals finds that the proposed accessory use does not substantially derogate from the public good.
C. 
In an undeveloped section of the Town restricted by this Bylaw a conditional permit of not more than two years duration for a structure or use not permitted by these Bylaws in the district where it is located but which is necessary to the development of such section.
D. 
A permit for a change of a non-conforming use to one no more harmful or objectionable.
E. 
A permit to allow houses, which because of their size have become unsuitable or unsalable for their original purpose due to changes in present day living conditions to be occupied by more families than allowed in the zoning district in which they are situated, under such conditions and limitations as will not substantially affect adversely the present characteristics of the district in which they are situated.
F. 
A permit to allow a use which is neither an exempt accessory use as defined in § 375-5.1 "exempt accessory use" nor a use otherwise permitted in the district if said use is owned or operated by an exempt institution and only under such conditions as the Board imposes in order to safeguard the health, safety and welfare of the neighborhood. If the chief activity of said use is a gainful activity usually conducted as a business, it shall be located on the same parcel as the exempt institution by which it is owned or operated.