For the purposes of this chapter, the Township of Tredyffrin is hereby divided into the following different types of districts, which shall be designated as follows:

The boundaries of said districts shall be shown upon the map which is attached to and made a part of this chapter and which shall be designated the "Zoning Map of Tredyffrin Township." The said map and all notations, references and other data shown thereof shall be as much a part of this chapter as if all were fully described herein.

The boundaries between districts are, unless otherwise indicated, either the center lines of streets or railroad rights-of-way, or such lines extended, or lines parallel thereto. Where dimensions are shown on the Zoning Map between a street and a district boundary line, they indicate that the district boundary line runs parallel to the street line at a distance therefrom equivalent to the number of feet so indicated.

When a district boundary line divides a lot held in single and separate ownership at the time of the adoption of this chapter, the regulations as to the use in the less-restricted district may extend over the portion of the lot in the more-restricted district a distance of not more than 50 feet beyond the district boundary line.