A single-family dwelling, two-family dwelling, cemetery, greenhouse, public utility plant, state, county or municipal building, airport, radio station, religious institution or a club established pursuant to the New York State
Not-For-Profit Corporation Law or otherwise, and qualified as a tax-exempt organization pursuant to 25 U.S.C.A. §
501(c)(7) and applicable regulations, as the same may be amended from time to time, existing in any district at the time of the passage of this chapter or any amendments thereto, shall be deemed a conforming use upon the lot then devoted to such use, provided that such use has been legally established, and the lot containing these uses may not increase in size.