1.   The Council may, from time to time, on its own initiative, on petition, or on recommendation by the Planning and Zoning Commission, after public notice and hearings provided by law, and after a report by the Commission or after 30 days’ written notice to the Commission, amend, supplement, or change the regulations or districts herein or subsequently established.

   2.   Whenever the owners of 50% or more of the area of the lots in any district or part thereof desire any amendment, supplement or change in any of the provisions of this chapter applicable to such area, they may file a petition with the Clerk requesting the Council to make such amendment, supplement or change. Such petition shall be accompanied by a map or diagram showing the area affected by the proposed amendment, supplement or change, together with the boundaries of the area and such petition shall immediately be transmitted to the Commission for an investigation and report. The Commission shall file its recommendations approving, disapproving or modifying the proposed amendment, supplement or change with the Council within 30 days thereafter.

   3.   If a written protest against any proposed amendment, supplement or change shall have been presented to the Council, signed by the owners of 20% or more, either of the area of the lots included in such proposed change, or of those immediately adjacent in the rear thereof, extending the depth of one lot or not to exceed 200 feet therefrom or of those directly opposite thereto, extending the depth of one lot or not to exceed 200 feet from the street frontage of such opposite lots, such amendment shall not become effective, except by the favorable vote of at least three-fourths of all the members of the Council.

   4.   Whenever a petition requesting an amendment, supplement, or change of any regulation prescribed by this chapter has been denied by the Council such petition cannot be renewed for one year thereafter unless it is signed by at least 50% of the property owners who previously objected to the change. This provision, however, shall not prevent the Council from acting on its own initiative in any case or at any time as otherwise provided in this section.