Do I need a permit for accessory dwelling unit (adu) in Unincorporated Klickitat County?
Yes. In Washington, accessory dwelling unit (adu) generally requires a permit, and Unincorporated Klickitat County is no exception.
A 2023 state law (chapter 334, Laws of 2023) requires cities and counties planning under the Growth Management Act to allow at least two ADUs on lots in urban growth areas that allow single-family homes, and bars owner-occupancy requirements (RCW 36.70A.681). Those cities and counties may not cap ADU floor area below 1,000 square feet and must allow ADUs converted from existing structures such as detached garages even if they break current setback or lot coverage rules (RCW 36.70A.681). The ADU law changes zoning only; it does not apply on lots with critical areas or their buffers, and the ADU still needs building permits and inspections. Creating an ADU inside an existing house triggers smoke alarms throughout the dwelling as required for new construction (WAC 51-51-0314).
Documents you may need
- Building permit applicationRequired
- Site plan with setbacks, lot coverage, and parkingRequired
- Construction drawings (floor plan, foundation, framing, sections)Required
- Washington State Energy Code compliance documentationRequired
- Separate electrical, plumbing, and mechanical permitsLikely required
Possible inspections
- Footing and foundation inspection
- Framing and rough-in inspections (electrical, plumbing, mechanical)
- Insulation inspection
- Final inspection before occupancy
Frequently asked questions
- Do I need a permit for accessory dwelling unit (adu) in Unincorporated Klickitat County?
- Yes. In Washington, accessory dwelling unit (adu) generally requires a permit, and Unincorporated Klickitat County is no exception. The documents and inspections sections on this page list what the building department typically asks for.
- Who issues the permit in Unincorporated Klickitat County?
- The local building department for Unincorporated Klickitat County handles permitting. This page lists its contact details and online portal. Your mailing city is not always the permitting authority, so confirm the jurisdiction before you apply.
- How do I find out the exact requirements for my project?
- Run the free PermitRoadmap check for your specific project and answers. It returns the likely permits, documents, inspections, and next steps, each linked to its official source.
PermitRoadmap is an independent informational service and is not affiliated with any city, county, state agency, or permitting authority. Results are informational and do not replace confirming requirements with the local permitting authority.