18.56.010   Definitions.


"Accessory dwelling unit" means a second dwelling unit either attached to or located on a lot occupied by a single-family detached dwelling. This unit provides a separate and completely independent dwelling unit with facilities for cooking, sanitation and sleeping, and has a separate and independent entry/exist than one utilized for the primary residence.


"Owner occupancy" means a property owner, as reflected in the real estate tax rolls, who makes his or her legal residence at the subject lot, as evidenced by voter registration, vehicle registration, or similar means, and actually resides upon the lot more than six months out of any given year.

(Ord. No. 909, § 2 (Exh. A), 6-18-2009)

18.56.020   Where authorized.

Accessory dwelling units shall be permitted within any residential district subject to review and compliance with the standards and requirements of this chapter.

(Ord. No. 909, § 2 (Exh. A), 6-18-2009)

18.56.030   Performance standards for accessory dwelling units.


Minimum Lot Size. All performance standards, including minimum yard setbacks and overall building coverage as set forth for the applicable zoning district shall be met with respect to the accessory dwelling unit. An accessory dwelling unit shall not be permitted upon any lot that is nonconforming due to lot size.


Number. No more than one accessory dwelling unit shall be permitted on a lot.


Location in Relation to Principal Residence. The accessory dwelling unit may be either detached or a part of the principal residence or an accessory building.


Zoning/Building Code Compliance. All new construction associated with an accessory dwelling unit shall meet the development standards for the applicable zone, except as modified by this chapter, and shall comply with all applicable city codes, including requirements for an efficiency dwelling unit as set forth in the International Building Code adopted by the city.


Owner Occupancy. An owner of the property for which an accessory dwelling unit permit is requested must occupy at least one dwelling unit located on the property.


Future Subdivision. Parcels upon which an accessory dwelling unit has been approved shall not be subdivided or otherwise segregated in ownership in a manner that would separate the accessory dwelling unit from the principal dwelling.


Maximum Size. An accessory dwelling unit shall not exceed fifty percent of the size of the primary dwelling on the lot or eight hundred square feet, whichever is less. Accessory dwelling units shall comply with the required site coverage, yard area requirements or building code setbacks as provided within the subject property's zone.


Scale. A detached accessory dwelling unit or accessory structure containing an accessory dwelling unit shall not exceed the maximum height allowed for a detached accessory building per the underlying zoning district.


Additions. Additions to an existing structure or newly constructed detached structures created for the purpose of creating an accessory dwelling unit, shall be designed in a manner consistent with existing roof pitch, siding and windows for the principal dwelling unit.


Parking. At least one off-street parking space in addition to the minimum required off-street parking from the primary dwelling unit shall be provided for an accessory dwelling unit.


Utility Connections. Utility accounts for accessory dwelling units shall be maintained in the name of the property owner. Accessory dwelling units may be served by the same water meter and sewer connection utilized for the primary residence if approved by the city, but shall be assessed a monthly service fee as established by the city's fee schedule or applicable ordinance. The city may require an applicant to provide documentation demonstrating capacity availability prior to allowing a joint connection. The city may require upgrades to a utility connection and the cost of such upgrades shall be borne by the applicant. If water or sewer service is not provided by the city, then the rules of the water or sewer district shall apply as to whether an additional hook-up and connection fees are required. Any water or sewer service as referenced in this section is subject to water or sewer availability.


Design and Appearance. The accessory dwelling unit shall be designed so that, to the degree reasonably feasible, the appearance of the building is consistent with that of the primary residence. At a minimum, the new exterior construction associated with creating an accessory dwelling unit should match the existing exterior materials and design of the principal residence, and the pitch of any new roof should match that of the principal residence. New landscaping shall conform with or improve existing landscaping.


Entrance Location. An attached accessory dwelling unit shall have a separate entrance to the outside from the entrance for the primary dwelling. For attached accessory dwelling units, the entrance to the accessory dwelling unit shall be located in such a manner as not to appear as a second primary entrance to the structure which contains the principal residence in an effort to maintain the appearance of a single-family residence.

(Ord. No. 909, § 2 (Exh. A), 6-18-2009; Ord. No. 948, § 53, 10-7-2010)

18.56.040   Review process.


Application. An applicant for an accessory dwelling unit shall submit an application on a form as provided by the department, including all application fees as set forth in the city's fee schedule. At a minimum, an application for accessory dwelling unit permit shall include plans for creating the accessory dwelling unit, evidence of current ownership and a certification of owner occupancy.


Certification of Owner Occupancy. The certification of owner occupancy shall be in the form of a notarized affidavit completed by the property owner as reflected in title records affirming that they make their legal residence upon the subject lot.


Review by Director. Accessory dwelling unit permit applications shall be processed as Type 2 permit pursuant to Chapter 18.08. Upon receipt of a complete application for an accessory dwelling unit, the director shall review and either approve, disapprove or approve with conditions an application for an accessory dwelling unit. As a condition of approval, the applicant shall record a covenant in a form approved by the city attorney with the King County department of records and elections, providing notice to future owners for the subject lot of the existence of the accessory dwelling unit, the owner occupancy requirements of the city, any conditions imposed as a part of the approval of the accessory dwelling unit and notice of the requirements for continued use of an accessory dwelling unit as set forth in this chapter.

(Ord. No. 909, § 2 (Exh. A), 6-18-2009)

18.56.050   Recognition of existing accessory dwelling units.

Accessory dwelling units that existed on or before the effective date of the ordinance codified in this chapter may be granted an accessory dwelling unit permit subject to the provisions of this section.


Time Limit. An application for an accessory dwelling unit permit for a pre-existing unit must be filed with the city for review by the planning commission within eighteen months of the effective date of the ordinance codified in this chapter.


Construction Code Compliance. Any space used for or included in the accessory dwelling unit shall have been constructed pursuant to a building permit issued by the city, and in compliance with the building and other construction codes that were in effect when construction was completed. The applicant must provide written documentation to verify construction code compliance. Alternatively, the applicant may verify code compliance for existing construction through the building department.


Development and Use Standards. Development and use of the pre-existing accessory dwelling unit shall comply with all provisions of this section.

(Ord. No. 909, § 2 (Exh. A), 6-18-2009)