Applicability; Nonconformities. Except as herein after provided, these Bylaws 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 these Bylaws or any amendments thereto, but shall apply to any change or substantial extension of such use, to a building permit or special permit issued after the first notice or said public hearing, to any reconstruction, extension or 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 a change to a single or two family residential structure does not increase the nonconforming nature of said structure.

Commencement of Construction or Operation. Construction or operations under a building permit or special permit shall conform to any subsequent amendments to these Bylaws, unless the use or construction is commenced within a period of not more than six (6) months after the issuance of the Building Permit or two (2) years in the case of a Special Permit and in any case involving construction, unless such construction is continued through to completion as continuously and expeditiously as is reasonable.