Do I Need a Permit for a Pole Barn in Washington State?

Yes—you do need a permit to build most pole barns in Washington State. But don't let that slow you down. At Columbia Structure, we help clients navigate the entire process.

Here’s what you need to know before submitting your application.

1. When Is a Permit Required?

According to state and county regulations, a building permit is typically required if your pole barn:

- Is over 200 square feet (or any size with utilities)

- Will be used for agriculture, storage, shop space, or residential purposes

- Is intended as a permanent structure (posts in the ground, slab, etc.)

Even basic “ag barns” often require approval for zoning, snow load, and setbacks.

2. What Agencies Oversee Permits?

- Cowlitz County Building & Planning – for Castle Rock, Kelso, Longview, etc.

- Lewis County Community Development – for customers further north

- City jurisdictions – If you're inside city limits, separate zoning rules may apply

3. What Do You Need to Submit?

Typical permit packages include:

- Engineered plans with load calcs

- Site plan showing location, access, setbacks

- Utility plan (if plumbing/electrical involved)

- Soil report or elevation data (for flood zones or slopes)

Don’t worry—we provide most of this for you as part of our kit or build service.

4. How Long Does It Take?

- Simple rural projects: 1–2 weeks

- City builds or barndominiums: 3–6+ weeks depending on plan checks

We help fast-track by submitting complete packages and coordinating with your local inspector.

5. Want Us to Handle It?

We offer full-service permitting as part of our pole barn design and build process. We know the forms, codes, and local quirks—so you can focus on the project, not the paperwork.