ADU rules in Yakima

YMC 15.09.045(B)(1) lets an ADU be 'its own stand-alone structure' or sit attached to or above a detached garage, and Table 4-1 lists Accessory Dwelling Unit as a Class (1) permitted use in every zone except AS, CBD and M-2. The only real gates are that the lot already holds a single-family dwelling and holds no duplex, multifamily, commercial or industrial use. A detached ADU takes accessory-structure setbacks (5 ft from side and rear property lines in residential districts under YMC 15.05.020(E)). Ord. 2022-011 (2022) deleted the old condition that limited ADUs to lots sized for a duplex, so there is no lot-size gate today.

The same subsection allows an ADU 'attached to the primary residence,' which is the code's category for additions and internal conversions that create a separate dwelling unit; Yakima has no separate internal or basement ADU classification. An attached ADU must meet the primary structure's setbacks and share a single sewer and water connection with the house (YMC 15.09.045(B)(5), (B)(8)(a)). The 1,000 sq ft cap and the one-ADU-per-lot limit apply the same way as for a detached unit.

YMC 15.09.045(B)(3) is a flat cap: 'The ADU's floor area shall not exceed one thousand square feet.' Height is not ADU-specific; the zone's general limit in Table 5-1 applies (35 ft in SR, R-1 and R-2; 50 ft in R-3), as do the lot coverage caps of 60 percent in SR/R-1/R-2 and 80 percent in R-3. Exterior walls must be similar in style, color and building materials to the primary dwelling, and any exterior stairs go in the rear or side yard.

Nothing in YMC 15.09.045, or anywhere else in Title 15, requires the owner to live in either unit; the 2020 version archived on the Wayback Machine had no such requirement either. The deed restriction the owner must record under (B)(11) exists to give 'notice to potential buyers of the ADU restrictions,' and the city's own posted deed template contains no occupancy covenant, only the design, size, sewer and no-separate-sale conditions. Washington's HB 1337 will independently bar owner-occupancy requirements (RCW 36.70A.681(1)(b)) when it binds Yakima at its periodic comprehensive plan update, so the city is already consistent with that rule.

YMC 15.09.045(B)(2) requires off-street parking under Chapter 15.06 for both the ADU and the primary residence, and Table 6-1 in YMC 15.06.040 sets 'Accessory dwelling units: 1 space' against 'Single-family dwelling, manufactured home, mobile home: 2 spaces.' Tandem driveway spaces count for residential uses, one space per 20 linear feet (YMC 15.06.050(D)), so an existing driveway can often satisfy the extra space. Yakima's downtown parking exemption expressly does not reach residential uses (YMC 15.06.040(C)) and the code has no transit-proximity waiver; HB 1337's ban on parking requirements within a half mile of a major transit stop does not bind the city yet.

An ADU is a Class (1) use, which YMC 15.04.020(A) defines as permitted provided district standards are met, and since Ord. 2023-026 added YMC 15.13.025 (amended by Ord. 2025-017) accessory dwelling units are exempt from even Type (1) zoning review when a compliant site plan is submitted with the building plans. In practice the path is a building permit from Code Administration plus the recorded deed restriction, with no hearing and no discretionary approval. Type (2) staff review is triggered only by situational factors such as floodplain, greenway or airport overlays or a request to adjust a development standard under YMC 15.13.020.

The code places no limit on renting either unit long term and has no residential rental licensing program. Short-term use is the constraint: YMC 15.09.045(B)(12) requires an ADU used as a short term rental to comply with YMC 15.09.080, and a short term rental (lodging for not more than thirty days, per YMC 15.02.020) is a Class (3) use in SR, R-1, R-2, R-3, B-1, SCC, LCC and GC, meaning a Type (3) hearing before the hearing examiner, and Class (1) only in the CBD. Table 4-2 makes a short term rental conducted as a home occupation Class (1) in SR, R-1, R-2 and R-3, but home occupations require the practitioner's primary residence to be on the property and must be conducted only by immediate family members residing in the dwelling. YMC 15.09.045(B)(9) also bars subdividing or segregating ownership so the ADU and the house end up on different lots, except through a Title 14 subdivision, so the ADU cannot be sold off separately today.