A property with one or more single-family dwelling units may be allowed to incorporate upon construction, or add later, no more than one accessory dwelling unit (ADU) on the same zoning lot subject to the following requirements:

   (A)   For the purpose of this section, the following definitions shall apply unless the context clearly indicates or requires a different meaning.

      (1)   Not more than one ADU shall be allowed on a property with one single-family dwelling unit.

      (2)   Not more than one ADU shall be allowed on a property with two or more single- family dwelling units.

      (3)   ADUs are prohibited on commercial property and on multi-family property.

   (C)   The ADU shall be limited in size as follows: No ADU shall exceed 1,000 square feet in size or exceed 50% of the size of the primary dwelling unit, whichever is greater.

   (D)   The city encourages, but does not require, that the property as whole and the buildings constructed on it, be designed in such manner that the property appears to be comprised of a single-family residence, and if applicable an accessory building, using materials and design as would typically be associated therewith in keeping with the neighborhood.

   (E)   Any non owner-occupied unit must meet the requirements of the Urbandale Housing Code and obtain a housing inspection certificate (commonly referred to as a rental certificate).

      (1)   Attached ADUs shall be required to follow the same minimum building setbacks and bulk requirements, as are required for the primary dwelling unit on the same property.

      (2)   Detached ADUs shall follow the same minimum building setbacks as required for the primary dwelling unit on the same lot, except that for detached ADUs less than 14 feet in height and less than 1,000 square feet in size, the minimum rear yard setback shall be ten feet or the same setback that is required for the primary dwelling unit, whichever is less. The minimum setback required along any street shall not be reduced.

      (3)   Detached ADUs on a property with one or more attached single-family dwelling units, such as on a townhouse property or on a property with a duplex, shall be required to follow the same minimum building setbacks and bulk requirements, as are required for the primary dwelling unit on the same property.

      (4)   No detached ADU shall be erected within the minimum setback required along any street, or within the minimum side yard setback required for a principal structure. Detached ADUs shall be located a minimum of ten feet from any other building or structure other than a fence on the same property unless fire protection is installed within the accessory dwelling unit, in accordance with the provisions of the Urbandale Building Code for an attached garage, in which case such minimum separation may be reduced to six feet.

   (G)   A detached ADU together with any other detached accessory buildings on the property, shall not exceed 30% of the rear yard.

   (H)   Direct access from each dwelling unit to the public right-of-way must be provided, such as with a continuous sidewalk or driveway.

   (I)   Within the lot, access to all structures for the purposes of provision of emergency services, must be maintained.

   (J)   Recreational vehicles, travel trailers, shipping containers, and any other wheeled or transportable structures shall not be used as ADUs; this shall not be construed to prohibit the use of a modular dwelling, manufactured home, or mobile home converted to real property and placed on a permanent foundation if such manufactured home or mobile home is required to be allowed by State of Iowa Code.

   (K)   No ADU shall be sold, divided or otherwise segregated in ownership from the primary dwelling unit.

(Am. Ord. 2025-11, passed 8-4-2025)