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18.50.025 Accessory Dwelling Units
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Purpose: Certain accessory structures may be converted to or developed for residential dwelling uses to promote efficient use of land. This section allows accessory dwelling units (ADUs) with standards to ensure that they do not change the residential character of the principal use. This provides affordable living options in prescribed zoning districts, while protecting their character and maintaining compatibility between uses. Examples of living arrangements for ADUs include seniors occupying a second family living unit or apartment, or families with elderly parents unable to live completely alone.

A. Applicability

1. This section applies to any accessory dwelling unit (“ADU”).

2. An ADU is a dwelling unit that is accessory to a principal single-family dwelling unit on the same lot. This includes a building or part of a building that provides complete independent living facilities for one (1) or more people, including a kitchen, living room, bathroom, and bedroom, and that is:

a.  Attached to the principal dwelling; or

b. A detached building on the same lot.

3. ADUs are permitted as accessory to principal single-family dwelling units in all residential districts, downtown districts or planned districts.

4. An ADU may be:

a. Constructed as a new building; or

b. Adapted from an existing building into an existing accessory structure on the same lot; or

c. Adapted from a portion of the principal dwelling unit.

5. Only one (1) ADU is allowed on a lot.

B. ADU Examples

Attached ADU

Detached ADU

ADU Portion of the Principal Dwelling

C. Standards

1. The ADU, detached or attached, must be set back at least six (6) feet behind the front of the principal structure and set back at least ten (10) feet from the rear lot lines. This does not apply to ADUs located within the interior of an existing principal structure.

2. The ADU must conform to side yard setbacks.

Attached ADU With Minimum Setbacks

Detached ADU With Minimum Setbacks

3.  Easements must be dedicated for separate utilities to be provided to each dwelling unit.

4. The architectural style of the ADU must conform to the architectural style and materials of the principal structure.

5. ADUs must not exceed a gross floor area of one thousand (1,000) square feet or more than fifty (50) percent of the principal structure’s floor area, whichever is less, or have more than two (2) bedrooms.

6. An ADU must not exceed two (2) stories or the height of the principal dwelling unit.

7. The ADU must not cause lot coverage to exceed seventy-five (75) percent, including the principal structures.

8. The ADU must meet current building code requirements.

9. The ADU must obtain a separate address to help guarantee emergency response.

10. The ADU must provide one (1) off-street parking space with access to a public street from the existing driveway. This space may be located in the existing driveway for the principal structure.

D. Process

1. An ADU requires a building permit only and a separate administrative review is not required.

2. Exceptions to the size, location, and architectural style requirements of this section may be approved by the Planning Official.

3. An applicant aggrieved by a final decision of the Planning Official may appeal to the Board of Zoning Appeals (see Section 18.40.220). (Ord. 22-22 § 12, 2022)