{"data":{"id":"us-wa/rcw-36.70a.685","jurisdiction":"us-wa","citation":"RCW 36.70A.685","heading":"Accessory dwelling units outside of urban growth areas.","body":"(1) Counties that are required or choose to plan under this chapter may allow detached accessory dwelling units outside of urban growth areas if the county meets the requirements in subsections (2) and (3) of this section, and such detached accessory dwelling units are subject to development regulations that include the following limitations:\n(a) No parcel may have more than one accessory dwelling unit, whether attached or detached;\n(b) The detached accessory dwelling unit must be subject to the water supply requirements of RCW 19.27.097 and any groundwater mitigation requirements adopted by the county or department of ecology;\n(c) The combined water withdrawal for the detached accessory dwelling unit, the principal unit, and any other domestic uses on the parcel may not exceed the use limitations in RCW 90.44.050 for domestic use;\n(d) Withdrawals of water by each dwelling unit on the parcel must be metered;\n(e) The applicant must provide documentation that the existing or proposed sewage or septic system is capable of handling the additional demand placed upon it by the detached accessory dwelling unit;\n(f) The gross floor area of the detached accessory dwelling unit may not exceed the gross floor area of what could be authorized by the county as an expansion of the principal unit to create an attached accessory dwelling unit; however, in no case may the gross floor area be greater than 1,296 square feet. Floor areas exclude garages, porches, and unfinished basements;\n(g) The detached accessory dwelling unit must utilize the same driveway or other means of ingress and egress as the principal unit;\n(h) The detached accessory dwelling unit must be sited within 150 feet of the principal unit;\n(i) The detached accessory dwelling unit may be the existing principal unit if the existing principal unit meets the requirements of this subsection, is a single-family dwelling unit, and a new principal unit that is a single-family dwelling unit is constructed on the same parcel;\n(j) The detached accessory dwelling unit must not be allowed on nonconforming lots under one acre; and\n(k) A parcel may not be subdivided for the purposes of avoiding the limits on development regulations described in this subsection.\n(2) In addition to the requirements in subsections (1) and (3) of this section, counties that allow detached accessory dwelling units outside of urban growth areas must have the following code enforcement measures in place:\n(a) A voluntary county code compliance process through which the owner of an unpermitted detached accessory dwelling unit may bring the unpermitted detached accessory dwelling unit into compliance with applicable regulations. In such a case, a permit penalty of at least double the normal permit fee must be applied;\n(b) Owners who do not seek voluntary compliance and are found to have constructed or placed a detached accessory dwelling unit without all required permits must be subject to a civil infraction of at least $1,000 and must be required to remove the detached accessory dwelling unit or ensure that it meets all existing development regulations, if applicable. A penalty of at least triple the normal permit fee must be applied if the accessory dwelling unit remains and meets all existing development regulations; and\n(c) Any owner who does not seek voluntary compliance and has received a civil infraction for constructing or placing an accessory dwelling unit without all required permits must be prohibited from receiving any permits for the placement or construction of new accessory dwelling units for a period of at least three years.\n(3) In addition to the requirements in subsections (1) and (2) of this section, counties that allow detached accessory dwelling units outside of urban growth areas must take the following actions to account for detached accessory dwelling unit development:\n(a) The county must track and annually report to the department the number of detached accessory dwelling unit permits completed;\n(b) Utilizing the data collected and reported in (a) of this subsection, the county must update its comprehensive land use plan during its next required review and all subsequent reviews required under RCW 36.70A.130(5) to properly account for the number of detached accessory dwelling units completed since June 11, 2026, and the projected development over the next 20-year planning period so that the housing units will not exceed the underlying densities for the comprehensive plan designations and zones outside of urban growth areas;\n(c) The county must limit future amendments to its comprehensive land use plan under (b) of this subsection such that these amendments may not occur more than once every five years; and\n(d) The county must include the following limits on population growth targets in its comprehensive plan:\n(i) If the county is a rural county as defined in RCW 43.160.020, the county may allocate no more than 10 percent of its rural population target to detached accessory dwelling units; and\n(ii) If the county is not a rural county as defined in RCW 43.160.020, the county may allocate no more than seven percent of its rural population target to detached accessory dwelling units.\n(4) Subsection (1) of this section is in addition to other county authority enumerated in this chapter and does not:\n(a) Affect or modify the validity of any county ordinance authorizing accessory dwelling units adopted prior to June 11, 2026;\n(b) Exclude other means of authorizing accessory dwelling units in urban or rural areas, if consistent with this section; or\n(c) Exclude other innovative techniques under RCW 36.70A.070(5)(b), 36.70A.090, or 36.70A.177, if consistent with this section.","path":["Title 36","Chapter 36.70A"],"source_url":"https://app.leg.wa.gov/rcw/default.aspx?cite=36.70A.685","current_through":"July 15, 2026","vintage":"","retrieved_at":"2026-09-06T02:31:23Z","sha256":"f7efefc33697f8accf0a2bb5f3bcf29c54fe37be4d7f169d88abccae709cbd0e","source_id":"us-wa","stale":false,"prev":"us-wa/rcw-36.70a.683","next":"us-wa/rcw-36.70a.690"},"notice":"GroundRules: Original legal text. Not legal advice."}