Counties may allow detached homes outside growth areas under limits

Counties may allow detached accessory homes outside urban growth areas if they adopt the listed limits. These rules apply to counties that must or choose to plan under the state land-use law and allow detached accessory homes outside urban growth areas. A parcel may have only one accessory home, attached or detached. Water use must meet state limits, withdrawals must be metered, and the applicant must show the sewage or septic system can handle the added demand. The home must meet county water and groundwater rules, use the principal home's driveway or other access, and be within 150 feet of it. Its size cannot exceed what the county could allow for an attached accessory home and cannot exceed 1,296 square feet. A detached home cannot be allowed on a nonconforming lot under one acre. An existing single-family home may become the detached accessory home if a new single-family principal home is built on the parcel. The section took effect June 11, 2026.

Counties that allow these homes must enforce permit rules, track permits, and account for the homes in their growth plans. These requirements apply to counties that allow detached accessory homes outside urban growth areas and to owners who place or build them without required permits. Counties must offer owners a voluntary way to bring an unpermitted home into compliance, with a permit penalty of at least twice the regular fee. Owners who do not seek voluntary compliance and are cited must pay at least $1,000 and remove the home or bring it into compliance; if it stays, a penalty of at least three times the regular fee applies. An owner who skips voluntary compliance and receives a civil infraction cannot get a permit to build or place another accessory home for at least three years. Counties must report completed permits each year and update their plans at the next required review and later reviews. The plans must account for completed homes and projected development over 20 years while keeping housing within planned densities. Plan amendments may occur no more than once every five years. Counties may assign no more than 10 percent of a rural county's rural population target, or 7 percent of another county's rural population target, to detached accessory homes. Counties must update plans at the next required review and later reviews; they may amend those plans no more than once every five years.