(a)   Purpose. The following standards are intended to accommodate two-family dwellings within predominantly single-family dwelling areas while protecting the public health, safety and general welfare of the community.
   (b)   Review and approval. Two-family dwellings must receive either final site and building plan approval or final development plan approval prior to issuance of a building permit. Because groupings of two-family dwellings have higher levels of neighborhood impact than stand alone, infill two-family dwellings, approval of groupings of two-family dwellings warrants a higher level of review and discretion. Plans for groupings of two-family dwellings may only be approved when a rezoning to a planned development overlay zoning district has first been approved by the City Council. Two-family dwellings qualify as a grouping when the parcel on which a two-family dwelling is proposed within 500 feet of a parcel occupied by an existing or proposed two-family dwelling, measured along existing or proposed public streets.
   (c)   Standards.
      (1)   Zoning district. Two-family dwellings must be located within the R-1 and R-4 Residential Zoning Districts.
      (2)   Site size. Two-family dwelling sites must have an area of at least 15,000 square feet for interior lots and 18,000 square feet for corner lots.
      (3)   Site width. Two-family dwelling sites must be at least 100 feet in width for interior lots and 120 feet in width for corner lots and must meet the median lot width requirements of city code § 21.301.01.
      (4)   Setbacks. Two-family dwelling garage and living space must meet the following minimum setback requirements from property lines:
50 feet
Side adjacent to street
50 feet
Side not adjacent to street
10 feet
30 feet
      (5)   Floor area. Two-family dwellings must have at least 960 square feet of living area per unit.
      (6)   Garages. Two-family dwellings must have at least two attached garage spaces per unit. Two-family dwelling garages must be at least 484 square feet per unit and must not exceed 900 square feet per unit. When a two-family dwelling is on a corner lot adjacent to two local streets as classified by the Comprehensive Plan, the garage for each unit must face a separate street. The height of the garage must not exceed the height of the two-family dwelling. Garage door openings, measured from the floor to the trim covering the door header must not exceed eight feet in height.
      (7)   Garage frontage. Two-family dwelling garage doors facing a public or private street is limited to 40% of the structure width facing the same street.
      (8)   Height. Two-family dwelling structure height must meet the height limits of city code § 21.301.10.
      (9)   Landscaping. Two-family dwellings must submit a landscape plan prior to building permit issuance that includes at least two trees per unit located within the front yard and at least one shrub per 1,000 square feet of developable landscaping area as defined in city code § 21.301.15(c)(2)(C).
      (10)   Recreational vehicles. Recreational vehicles on two-family dwelling unit sites must meet the requirements of city code § 21.301.13 and are limited to one recreational vehicle per unit stored outside.
      (11)   Storage. See city code § 21.301.16(a) for storage requirements.
      (12)   Accessory buildings. Accessory buildings on two-family dwelling sites are limited to one per unit, must not exceed 120 square feet per building and must meet the standards of city code § 21.301.19.
      (13)   Attachment required. The two units in a two-family dwelling must have a common wall of at least ten feet in length or be oriented in an over/under relationship.
      (14)   Home businesses. Type I home businesses are allowed within two-family dwelling units subject to the standards of city code § 21.302.13. However, Type II home businesses as defined in § 21.302.13 are not allowed within two-family dwelling units.
      (15)   Utilities. Two-family dwellings are prohibited on sites not served by municipal sewer and water. Utility connections must satisfy the requirements of city code §§ 11.12 and 11.34.
      (16)   Subdivision. The City Council may approve the subdivision of two-family dwellings and the lot upon which the two-family dwelling is located or is proposed to be constructed to allow separate ownership of each unit of the two-family dwelling subject to the following standards:
         (A)   Each of the lots created by the subdivision must be equal in area or as near equal in area as is reasonably possible;
         (B)   Each lot so created must contain at least one-half of the minimum land area requirement for a two-family dwelling;
         (C)   Except for setbacks along the common property line, all other setback and yard requirements must be met;
         (D)   The subdivision of the lot must be accomplished by plat in accordance with the subdivision regulations of the city code including required public hearings for plat approval;
         (E)   A maintenance agreement must be recorded with the county for each parcel created that contains an agreement by each property owner to:
            (i)   Continually maintain all portions of the building’s exterior with materials and finish that are accepted by the State Building Code as appropriate to the application and the location;
            (ii)   Use matching exterior materials on the entire building with respect to material type, color and texture;
            (iii)   Properly maintain the approved landscaping plans, screening plans and any approved storm water management plan for the properties; and
            (iv)   Provide adequate maintenance and repair of all common walkways, driveways, and, if allowed, common sewer and water facilities.
         (F)   All outstanding violations of the city code, if any, must be corrected prior to approval of the final plat by the city or a surety (cash, bond or letter of credit) must be deposited with the city to assure correction.
      (17)   Building Code compliance. Two-family dwellings must meet current State Building Code provisions, including, but not limited to, fire resistance and sound insulation standards between units.
      (18)   Storm water. To mitigate the impacts of increased storm water runoff rates and volume, two-family dwellings must meet the following storm water standards:
         (A)   Erosion and sediment control must meet the requirements of Chapter 16;
         (B)   Impervious surface area must not exceed 45% of the two-family dwelling site area; and
         (C)   If impervious surface area exceeds 35% of the two-family dwelling site area, storm water management plans meeting the requirements of Chapter 16 of the city code and the city’s comprehensive surface water management Plan must be approved by the City Engineer or designee prior to issuance of a grading, foundation, or building permit.
(Ord. 2009-26, passed 9-14-2009; Ord. 2010-29, passed 11-1-2010; Ord. 2011-16, passed 8-1-2011; Ord. 2014-5, passed 2-3-2014; Ord. 2015-5, passed 1-26-2015; Ord. 2015-15, passed 5-18-2015; Ord. 2015-28, passed 11-2-2015; Ord. 2015-33, passed 11-16-2015; Ord. 2019-2, passed 1-7-2019; Ord. 2019-3, passed 1-7-2019; Ord. 2019-50, passed 12-16-2019; Ord. 2021-7, passed 4-26-2021)