The Washington County Planning Commission voted unanimously on Jan. 7, 2025, to recommend approval of Ordinance 912, which would amend the countycomprehensive plan and community development code to allow rural accessory dwelling units (ADUs) in the county's rural residential districts.

Senior planner Todd Borkowitz, presenting the staff report, said the ordinance would "allow accessory dwelling units or rural ADUs in the rural residential areas of the county." He told commissioners the change implements state allowances while retaining county authority to add safeguards.

Why it matters: The state now enables counties to allow two rural ADU types: a new rural ADU accessory to an existing single detached dwelling and a rural historic ADU converting an existing historic home when a new primary dwelling is built. Those state rules limit eligible lots (for example, lots must be at least 2 acres, cannot be inside urban reserves, and are screened out where groundwater use is restricted). Borkowitz emphasized that counties may be more restrictive than state law and proposed two additional county requirements for rural historic ADUs to improve public safety.

Key provisions and limits
- One rural ADU or conversion of one historic home to a rural historic ADU would be allowed per lot in rural residential districts, subject to state minimums and county additions.
- Rural ADUs are limited to 900 square feet of usable/habitable floor area. For a historic home converted to a rural historic ADU, the historic home may not be enlarged more than 120% of its square footage at the time construction of the new dwelling begins.
- State filters include minimum lot size (2 acres), exclusion from urban reserves, and prohibitions in groundwater-restricted areas unless a property is served by an outside water provider; rural ADUs (but not rural historic ADUs) must be served by a structural fire protection service provider.
- The county proposed two added requirements for rural historic ADUs: the lot must not be subject to an order or pending action declaring it a nuisance, and the lot must be served by a structural fire protection service provider with adequate access for firefighting and safe evacuation.
- Vacation occupancy would not be allowed for rural ADUs; Todd read the statutory definition for vacation occupancy, noting it applies to short-term, non-principal stays that do not exceed 45 days.

Public comment: Three people spoke in favor of limited changes and raised concerns. Jacob van der Eames said ADUs would help his multigenerational family "be able to help families like this" but noted mapping that places his property inside a groundwater conservation area excluded them from eligibility. Suzanne Smith asked for flexibility on the 100-foot proximity requirement for properties with difficult topography. Robert Bailey reiterated written testimony expressing concern about the potential for vacation or short-term rentals and objections to using so-called "undesignated" land for housing.

Commission discussion and follow-up: Commissioners asked staff to confirm technical questions about groundwater-restricted areas and whether hauled or purchased water held in cisterns would meet statutory requirements; staff said they would check statutory language and noted some exceptions exist where community water plan or district coverage applies. Commissioners also clarified that the 100-foot proximity requirement applies only to rural ADUs (not rural historic ADUs) and that this requirement is set by state rule and would require legislative change to alter.

Vote and next steps: A motion to recommend approval passed by a 7-0 vote; the commission will transmit its recommendation to the Board of Commissioners, which postponed action on the county's related resolution and is scheduled to consider community participation changes and related items at upcoming meetings (the assistant director referenced Jan. 27 and Feb. 3 as forthcoming dates).