(A)   (1)   For the purpose of regulating and restricting the heights and size of buildings and other structures, the percentage of lot that may be occupied, the size of yards and other open spaces, the density of population and the location and use of buildings, structures and land for trade, industry, residence or other purposes, the city is hereby divided into districts of which there shall be six classes in number and which shall be known as:
         (a)   “R-1” Single-Family Dwelling District;
         (b)   “R-2” Multi-Family Dwelling District;
         (c)   “R-3” Mobile Homes;
         (d)   “C-1” Commercial-1 District;
         (e)   “C-2” Commercial-2 District; and
         (f)   “M-1” Manufacturing District.
      (2)   The boundaries of the districts described above are shown on the map on file in the City Clerk’s office and made a part of this chapter, which map is designated as the “Zoning District Map”. Said district map and all notations, references and other information shown thereon, are made a part of this chapter and shall have the same force and effect as if said map and said data thereon were fully set forth or described herein. Said map shall, on its face, be identified and verified in the manner following: It shall bear the title “ZONING DISTRICT MAP Clifton, Texas”; it shall bear even date with the passing of this chapter; it shall bear the name of the Mayor; and it shall be attested by the signature of the City Clerk. The original of said map shall be kept in a proper place in the municipal building.
      (3)   Whenever any street, alley or other public way is lawfully vacated by the Council of the city, the zoning district adjoining each side of such street, alley or public way shall be automatically extended to the center of such vacated area and thereafter all land included in said vacated area shall be subject to all applicable regulations of the extended districts.
      (4)   All territory hereafter annexed to the city shall be classified as “R-1”, One- Family Dwelling District, until permanently zoned by the governing body of the city. The city’s Planning and Zoning Commission shall, as soon as practicable after annexation of any territory to the city, institute proceedings on its own motion to give the newly annexed territory permanent zoning, and the procedure to be followed shall be the same as is provided by law for the adoption of original zoning applications, except as hereinafter provided.
         (a)   No building shall be erected, converted, enlarged, reconstructed or structurally altered, and no building or land shall be used for any purpose that is not permitted in the district in which the building or land is situated.
         (b)   No building shall be erected, converted, enlarged, reconstructed or structurally altered to exceed the height limit herein established for the district in which the building is situated.
         (c)   The minimum yards and other open spaces, including lot area per family, required by this chapter for each and every building existing at the time of the passage of this chapter or for any building hereafter erected shall not be encroached upon or considered as yard or open space requirements for any other building, nor shall any lot area be reduced to an area less than the district requirements of this chapter.
         (d)   Every building hereafter erected or structurally altered shall be on a lot, as herein defined, and in no case shall there be more than one main building on one lot, except as otherwise provided in this chapter.
(2012 Code, § 93-2)
   (B)   (1)   Use regulations.
         (a)   Accessory buildings. No accessory building shall be constructed upon a lot until the construction of the main use building has been actually commenced. No accessory building shall be used unless the main use building on the lot is also being used.
         (b)   Railroad rights-of-way. On all existing rights-of-way or railroad companies, regardless of the zoning district in which such rights-of-way are located, railroad track accessories to railroad movement may be constructed or maintained.
      (2)   Area and density regulations.
         (a)   In a district in which commercial or industrial buildings are built with one or more stories for residential purposes above the commercial or industrial uses, no side yards will be required for the residential portions of the building; provided that, the part of the building intended for residential use is not more than two rooms deep from front to rear.
         (b)   No yard or other open space provided about any building for the purpose of complying with the provisions of these regulations shall again be used as a yard or an open space for another building. Every part of a required yard shall be open to the sky and unobstructed by buildings, except for accessory buildings in the rear yard and except for the ordinary projection of skylights, sills, belt courses, cornices and other ornamental features which may project into yards a distance of not more than two feet.
         (c)   Terraces, uncovered porches, platforms and ornamental features which do not extend more than three feet above the floor level of the ground (first) story may project into a required side yard; provided, these projections be a distance of at least two feet from the adjacent side lot line.
      (3)   Front yards; vision clearance. On any corner lot on which a front or side yard is required, no wall, fence, sign or other structure shall be permitted more than three feet above curb level within 15 feet of the intersection of the property lines.
      (4)   Side yards.
         (a)   A side yard of not less than 25 feet on the side of the lot adjoining on an R-1 or R-2 District shall be provided for all schools, libraries, churches, community houses, clubs and other public or semi-public buildings hereafter erected or structurally altered.
         (b)   Where a lot in the C-1 or C-2 or I Districts is not used for residential purposes and abuts upon R-1 or R-2 Districts, a side yard shall be provided of not less than five feet.
      (5)   Rear yard.
         (a)   In the R-1 or R-2 Districts, accessory buildings shall not occupy more than 30% of the required minimum rear yard area. Accessory buildings shall be a minimum of 12 feet from the main use building. In the R-1 or R-2 Districts, no necessary buildings shall be more than one story in height.
      (b)   In computing the depth of a rear yard where such yard opens into an alley, one-half of the width of such alley may be assumed to be a portion of the required yard.
(2012 Code, § 93-8)