For the purpose of this chapter, the Town is hereby divided into use districts, as hereinafter provided. The boundaries of these districts are hereby established as shown on the Town's Zoning Map, dated December 10, 1986, as revised, and on file in the office of the Town Engineer. This map is by reference incorporated into and made a part of this chapter. Any changes in the number of districts or in district boundaries shall be noted on the Zoning Map as each such change is adopted through a Zoning Bylaw amendment. It shall be the responsibility of the Planning Board to update this Zoning Map. The districts are as follows:

Any alteration, construction or operation allowed by building permit or special permit under this chapter shall conform to any amendment of this chapter unless construction or operation is commenced within a period of six months of the issuance of the permit and construction is continued through to completion as continuously and expeditiously as is reasonable.

When a boundary line between use districts, height districts or area districts, as established by this chapter and the Town's Zoning Map, divides a lot in single ownership on the effective date of this chapter, the requirements applying to the least restricted portion of such lot shall be considered as applying to the entire lot, provided that the most restricted portion of such lot is entirely within 150 feet of the district dividing boundary line. The use so extended shall be deemed to be conforming.