Chapter 17.312
ACCESSORY DWELLING

Sections:

17.312.010    Purpose.

17.312.020    Definition.

17.312.030    Use and restrictions.

17.312.040    Development and design standards.

17.312.010 Purpose.

ORS 197.312 requires that at least one accessory dwelling be allowed per detached single-family dwelling in every zone within an urban growth boundary that allows detached single-family dwellings. Accessory dwellings are an economical way to provide additional housing choices, particularly in communities with high land prices or a lack of investment in affordable housing. Accessory dwelling units provide an opportunity to increase housing supply in developed neighborhoods and can blend in well with single-family detached dwellings. Accessory dwellings may be used as long-term housing rentals (no less than 30 days per month and not a vacation rental) or as a property owner’s residence. [Ord. 524 § 7 (Exh. A), 2020; Ord. 518 § 8 (Exh. 1), 2019; Ord. 503 § 1 (Exh. B), 2018].

17.312.020 Definition.

“Accessory dwelling unit” is an interior, attached or detached residential structure that is used in connection with or that is accessory to a single-family dwelling. [Ord. 518 § 8 (Exh. 1), 2019; Ord. 503 § 1 (Exh. B), 2018].

17.312.030 Use and restrictions.

An accessory dwelling unit, where allowed, is subject to review and approval through a Type II procedure, pursuant to CBDC 17.130.090, and shall conform to the following restrictions:

(1) One accessory dwelling is allowed per legal lot of record containing a detached single-family dwelling. The unit may be a detached building, in a portion of a detached accessory building (e.g., above a garage or workshop), a unit attached or interior to the primary dwelling (e.g., an addition or the conversion of an existing floor) or tiny home subject to the requirements of CBDC 17.312.040(1)(g);

(2) The accessory dwelling unit may not be used as vacation rental;

(3) Construction of an accessory dwelling unit must meet the minimum standards of the current state residential specialty code or the requirements of CBDC 17.312.040(1)(g);

(4) A separate address shall be assigned to the accessory dwelling and the address shall be clearly identified, as required by state building code; and

(5) A deed restriction must be recorded with the property advising future owners and lenders of the use restrictions. The deed restriction document will be created by the city and recorded at the county clerk’s office. [Ord. 524 § 7 (Exh. A), 2020; Ord. 518 § 8 (Exh. 1), 2019; Ord. 503 § 1 (Exh. B), 2018].

17.312.040 Development and design standards.

(1) Development Standards.

(a) A detached accessory dwelling unit shall not exceed 1,000 square feet of floor area, or 75 percent of the primary dwelling’s total floor area, whichever is smaller.

(b) An attached or interior accessory dwelling unit shall not exceed 1,000 square feet of floor area, or 75 percent of the primary dwelling’s total floor area, whichever is smaller. However, an accessory dwelling unit that results from the conversion of a level or floor (e.g., basement, attic, or second story) of the primary dwelling may occupy the entire level or floor, even if the floor area of the accessory dwelling unit would be more than 1,000 square feet.

(c) Accessory dwellings shall meet all other development standards (e.g., height, setbacks, lot coverage, etc.) for buildings in the designated zoning district, except that conversion of an existing legal nonconforming structure to an accessory dwelling is allowed; provided, that the conversion does not increase the nonconformity.

(d) Accessory dwellings are not subject to the density requirements of the zone.

(e) Accessory dwellings shall conform to the overall maximum lot coverage and setback requirements of the underlying zone.

(f) Structures detached from the primary home on a residential lot may be converted to an accessory dwelling unit if the structure meets the standards and requirements of the Oregon Specialty Building Code, this title’s setback requirements and does not eliminate an existing functional garage.

(g) A permanent tiny home may be attached to an approved foundation subject to the Oregon Residential Specialty Code (ORSC) and Oregon Fire Code or U.S. Department of Housing and Urban Development (HUD) Manufactured Home Construction and Safety standards.

(2) Design Standards.

(a) An accessory dwelling unit, located in a historic district, must comply with the historic district regulations.

(b) An accessory dwelling unit located on the same lot as a structure listed on the National Register of Historic Places or listed as a cultural resource will be held to a high development standard, in that the exterior must be compatible with the primary structure.

(c) The exterior finish and trim materials of a detached accessory dwelling unit shall be similar to the primary dwelling unit in terms of type, size, placement, and finish.

(d) The roof pitch of a detached accessory dwelling unit shall be similar to the roof pitch of the primary dwelling. [Ord. 524 § 7 (Exh. A), 2020; Ord. 518 § 8 (Exh. 1), 2019; Ord. 503 § 1 (Exh. B), 2018].