Thurston County commissioners direct staff to 'support' 5% rural‑growth aim, clear path for detached ADUs and conservation subdivisions

The Thurston County Board of County Commissioners on Dec. 2 directed staff to include a revised comprehensive‑plan ordinance that ‘‘supports a sustainable development pattern’’ with a target to direct roughly 5% of new growth to rural areas, rather than language that would legally ‘‘establish’’ the target. The change reflects legal counseladvice intended to reduce exposure to Growth Management Hearings Board appeals while preserving the countyads policy aim.

Planning and legal staff told commissioners recent case law has made mandatory targets more likely to trigger appeals that would require zoning or regulatory changes to implement. "Based on very recent case law, we would essentially be on the hook for having enacting regulations or zone changes," a planning staff member said during the discussion, urging the softer "support" formulation so the county can keep the goal without immediate regulatory obligations.

Why it matters: commissioners said the phrasing affects what the county can require and how quickly implementation steps must follow. Support language still puts the county on record as pursuing more compact development and gives staff direction to prepare an implementation plan the board can act on Dec. 16.

Detached ADUs: board approves direction to draft implementing language Commissioners also debated whether to allow detached accessory dwelling units (ADUs) in rural unincorporated areas and how to limit their impacts. After extensive discussion about density, equity and environmental protections, the board voted to direct staff to draft ordinance language permitting rural detached ADUs of up to 1,000 square feet with "flexibility" on the 100‑foot proximity standard (for example, allowing placement tied to an existing driveway to avoid creating extra impervious surface). Staff committed to circulate draft code language to the board before final action.

Supporters said permitting ADUs recognizes existing household needs and can regularize housing that is sometimes built without permits; opponents warned that loosening rural restrictions risks eroding the countyads rural‑growth goals. Commissioners emphasized the change is a direction to staff to prepare concrete language to return to the board for final approval.

Cluster developments and conservation tools: staff to remove barriers The board also directed staff to prepare code changes to remove barriers to cluster or conservation subdivisions designed to concentrate housing on smaller footprints while conserving farmland, habitat and water resources elsewhere. Planning staff highlighted examples in Thurston County where clustering preserved hundreds of acres of working land and habitat while concentrating homes in a compact pattern.

Battery energy storage code delayed Separately, staff requested and the board agreed to delay a proposed new code for battery energy storage systems so staff can gather additional technical input; the administration will bring a revised package to a January–February 2026 work session.

What comes next: staff will prepare ordinance text and draft development‑code language on the boardads direction and circulate it to the commissioners before the Dec. 16 meeting for final action. The board also asked staff to provide reporting and monitoring commitments so the policies and implementing code changes can be evaluated against the countyads goals.