Except as hereinafter provided, no building or premises shall be used, and no building shall be extended, erected, converted, moved, rebuilt or altered except in conformity with all the district regulations established by this Zoning Code for the district in which it is to be located and until a building permit has been secured from the Zoning Administrator as provided herein.

   Not more than two dwellings are permitted on any lot, tract or parcel of land until the same has been subdivided according to Iowa Statute.

   No lot shall be so reduced in area that any required yard or other space will be smaller than is prescribed in this Zoning Code for the district in which it is located. No lot, tract or parcel of land in a residence district shall be platted or reduced to an area of less than 8,712 square feet, or to an average width of less than 66 feet; provided, the Council may waive this provision under special circumstances, upon recommendation of the Planning and Zoning Commission.

   No yard or other open space on one lot shall be considered as providing a yard or open space for a building on any other lot, and no yards or other open space about an existing building or any building hereafter constructed for the purpose of complying with the provisions of this Zoning Code, shall be considered as providing a yard or open space for any other building.

   Whenever any street, road or other public way is vacated by official action of the City, the Zoning District adjoining each side of such street, road or public way shall be extended to the center of such vacation and all area included in the vacation shall be subject to all the regulation of the extended district.

   If actual construction has been started on any building at the time of the passage of the ordinance codified by this chapter, nothing contained herein shall require any change in the plans, construction or designated use of any such building or part thereof. No building shall be erected, converted, enlarged, reconstructed or structurally altered except in conformity with the height and area regulations of the district in which such building is located, except that in any residential district a property owner may convert, reconstruct, enlarge or structurally alter a building upon application to the issuing authority, without conforming to the area regulations, front yard regulations, side yard regulations, rear yard regulations of residential district, but such a property owner shall not exceed the nonconformity existing prior to such conversion, reconstruction, enlargement or structural change.

   Except in an agricultural or industrial district, the principal building on a lot shall front on a street or public lake.

   Any portion of a building which is covered by a roof and which is enclosed on three or more sides shall be considered as a part of the building.

   The keeping or raising of poultry, livestock or rodents is prohibited within the corporation limits of the City.