County Building Permits
Cowlitz County Building Permit Guide (Unincorporated Area)
How to apply for a building permit in unincorporated Cowlitz County, Washington. Permit authority, application steps, fees, and inspection requirements.
Permit Authority
All properties in unincorporated areas of Cowlitz County.
- Department
- Department of Building and Planning
- Address
- 311 First Avenue North, Kelso, WA 98626
- Phone
- (360) 577-3050
Online Permit Portal
Platform: Paper-based application system • Account required: No • Submission: In-person only
Application Process
- Obtain permit application forms from the Department of Building and Planning.
- Prepare a plot plan showing actual dimensions, existing and proposed buildings, setback information, and zoning compliance verification.
- Prepare construction plans and specifications.
- If applicable, provide proof of contractor registration with Washington State L&I.
- Submit completed application, plot plan, construction plans, and payment of plan review fees in person or by mail.
- County staff reviews application for completeness and performs plan review.
- Pay remaining permit fees upon approval and before beginning work.
Typical processing time: Residential: 2-4 weeks typical; Commercial: 3-5 weeks typical. Timeframes may vary based on complexity and workload.
General Requirements
Building permits are required for all construction, alterations, and repairs in unincorporated Cowlitz County.
Required Documents
- Completed permit application forms
- Plot plan with actual dimensions and building locations
- Construction plans and specifications
- Proof of contractor registration with Washington State L&I (if applicable)
- Payment of plan review fees
- Permit validity
- Permit must be activated by inspection within 180 days of issuance or it expires.
- Building code
- 2021 International Building Code (IBC) with Washington State amendments (effective March 5, 2024); 2021 IRC, 2021 IMC, 2021 IFC, 2021 IFGC, 2021 IEBC, Uniform Plumbing Code (UPC), Washington State Energy Code (WSEC)
- Owner-builder
- Property owners may obtain permits for work on their own property.
- Contractor requirements
- All contractors must be registered with Washington State Department of Labor and Industries (L&I) under RCW 18.27.
Fees
- Minimum permit fee
- Valuation-based
- Plan check fee
- 65% of building permit fee for residential; 70% for commercial
- Permit fee formula
- Valuation-based fees per County resolution; exact rates available from Department
- Trade permit fee
- Varies by trade
- Reinspection fee
- Applies for failed inspections or incomplete work
- Payment note
- Contact Department for current fee schedule and payment methods.
Work That Does NOT Require a Permit
- Repairs, maintenance, re-roofing, or minor alterations to existing buildings that do not affect structural supports, egress, fire-rated construction, or fire protection (for firms with on-site engineering and maintenance staff)
- Installation of tanks, process equipment, wire mesh fences up to 8 feet high
- Small slabs (less than 50 sq ft) for equipment bases less than 4 feet high
- Pressure vessels registered with Washington State L&I
- Process ventilation equipment meeting IFC requirements
- Access stairs, platforms, or walkways integral to equipment (must meet WISHA standards)
- Conveyors nominally at ground or floor level
Important: Electrical work is handled by Washington State L&I, not Cowlitz County. Always verify exemption status with the Department of Building and Planning before proceeding without a permit.
Inspections
How to Schedule
- (360) 577-3050 (phone)
- Scheduling deadline
- 24-hour advance notice typically required
- Inspection hours
- Monday-Friday, 8:00 AM to 5:00 PM (closed for lunch 12:00-1:00 PM)
Typical inspection sequence: Inspections required at various stages of construction. Final inspection required for certificate of occupancy/completion.
Additional Resources
- Building code: 2021 International Building Code (IBC) with Washington State amendments (effective March 5, 2024); 2021 IRC, 2021 IMC, 2021 IFC, 2021 IFGC, 2021 IEBC, Uniform Plumbing Code (UPC), Washington State Energy Code (WSEC)
- Verify contractor license: WA L&I Contractor Lookup
- License lookup guide: Washington Contractor License Requirements
- Contract template: Washington Homeowner-Contractor Agreement
- Washington hub: Washington Contractor License & Permit Hub
Information on this page was last verified: March 2026. Permit rules and fees change — confirm current requirements directly with the Department of Building and Planning before applying.
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