Background: Growth Management Act. The Growth Management Act (GMA) is the comprehensive land use planning framework for county and city governments in Washington. Enacted in 1990 and 1991, the GMA establishes numerous planning requirements for counties and cities obligated by mandate or choice to fully plan under the GMA and a reduced number of directives for all other counties and cities. Twenty-eight of Washington's 39 counties, and the cities within those counties, are planning jurisdictions.

Local Planning for Accessory Apartments. Local governments are required to have accessory apartments, commonly referred to as ADUs, provisions incorporated in their development regulations, zoning regulations, or official controls. These provisions must be consistent with a 1993 report from the Department of Community, Trade, and Economic Development (CTED) that provided recommendations to the Legislature designed to encourage the development and placement of accessory apartments in areas zoned for single-family residential use. The CTED recommendations include standards and criteria regarding size, parking, design, and quantity of accessory apartments. "Local government" means a county planning under the GMA, a city with a population of over 20,000, and a county with a population of over 125,000.

Accessory Dwelling Unit Regulation. In 2019, the Legislature encouraged fully planning cities to take an array of specified planning actions to increase residential building capacity. Specified planning actions relating to ADUs include authorizing attached ADUs on all parcels containing single-family homes where the lot is at least 3200 square feet in size, and permitting both attached and detached ADUs on all parcels containing single-family homes if the lots are at least 4356 square feet in size. If this planning action is taken:

qualifying city ordinances or regulations could not provide for on-site parking requirements, owner occupancy requirements, or square footage limitations below 1000 square feet for the ADU or prohibit the separate rental or sale of ADUs and the primary residence;
cities would be required to set applicable impact fees at no more than the projected impact of the ADU; and
to allow other local flexibility, ADUs would be subject to such regulations, conditions, procedures, and limitations as determined by the local legislative authority, and be required to follow all applicable state and federal laws and local ordinances.

Summary: By July 1, 2021, any city within a county planning under the GMA must adopt or amend ordinances, regulations, or other official controls that do not require the provision of off-street parking for ADUs within 0.25 mile of a major transit stop. However, such a city may require the provision of off-street parking for an ADU located within 0.25 mile of a major transit stop if the city determines the ADU is in an area with a lack of access to street parking capacity, physical space impediments, or other reasons to support that on-street parking is infeasible for the ADU. In addition, such a city that has adopted or substantively amended its ADU regulations within the previous four years is exempt from the new ADU requirements regarding off-street parking. Major transit stop is defined as:

a stop on certain high capacity transportation systems;
commuter rail stops;
stops on rail or fixed guideway systems, including transitways;
stops on bus rapid transit routes or routes that run on high occupancy vehicle lanes; or
stops for a bus or other transit mode providing fixed route service at intervals of at least 15 minutes during the peak hours of operation.

Beginning July 1, 2021, the new ADU requirements apply and take effect in any GMA city that has not adopted or amended such regulations and supersede, preempt, and invalidate any conflicting local development regulations.

Governing documents of condominium, homeowner, and common interest ownership associations are not modified or limited by the provisions of the bill.

Votes on Final Passage:

Senate	31	17
House	94	3	(House amended)
Senate	41	8	(Senate concurred)