Skamania County, WA ADU (accessory dwelling unit) Rules (2026): County, City, or Gorge?

Skamania County is gorge country: Stevenson, North Bonneville, Carson, and a lot of land that is not in any city. Washington’s urban ADU statute, summarized in the Washington ADU laws guide, doesn’t cover everything here. Many parcels also sit in the Columbia River Gorge National Scenic Area. Scenic-area review can control where a second dwelling goes, how it looks, and whether it is allowed at all. Confirm that overlay before you treat a state ADU law as a yes.

White Salmon and Bingen are across the line in Klickitat County. Hood River is in Oregon. Their rules don’t apply to a Skamania parcel.

What to confirm before you pick a model

• City limits (Stevenson or North Bonneville) versus unincorporated county.
• Whether the parcel is inside the National Scenic Area, and which agency reviews it.
• Septic or sewer, water, and shoreline or slope constraints. Gorge lots run into access and critical-area problems as often as zoning ones.
• A legal road approach and a place to stage a trailer. Scenic roads and tight driveways affect how the home gets delivered.
• Any design review that could reject a roof form or exterior the factory builds. Find that out before you pick finishes.

For Gorge delivery and how Skamania compares with other mountain counties, see mountain cabins and ADUs in the Cascades.

What Wolf does

We start with the parcel: who reviews it, whether a module can reach the pad, and whether scenic-area rules rule the project out. The house would be built in Battle Ground, and turn-key service in Washington still depends on a lot the county, the city, or the Gorge Commission will permit.

If the rules are the open question, send the address and mention it’s in Skamania County. If the scenic area won’t allow a second home on the parcel, we’ll tell you before any design work starts.

General planning notes. Scenic-area and county rules change by parcel. Confirm them with the reviewing agency before you commit to a design.