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When a permit is required
Permit triggers and exempt work for Snohomish County
A building permit is required for most construction in unincorporated Snohomish County.
- Exempt One-story detached accessory structures under 200 sq ft (with limitations)
- Exempt Fences under 6 feet high (setback requirements still apply)
- Exempt Retaining walls under 4 feet high
- Exempt Driveways and sidewalks on private property
- Exempt Painting, papering, and similar finish work
- Exempt Minor repairs
Note: While exempt from building permits, other permits may be required (setback compliance, flood hazard permits, etc.). See Assistance Bulletin #74 and Snohomish County Code Section 30.50.103 for the complete exemption list.
- Residential Building Application Checklist
- Structural plans (stamped by WA licensed engineer/architect for complex projects)
- Site plan
- Drainage plan
- Water and Sewer Approval from Snohomish County Health Department (if applicable)
- Building code
- 2021 International Building Code (IBC), 2021 International Residential Code (IRC), 2021 International Mechanical Code (IMC), 2021 International Fire Code (IFC), Uniform Plumbing Code, and Washington State Energy Code, all with Washington amendments (effective March 15, 2024).
- Contractor requirements
- All contractors must be registered with Washington State L&I.
Application process
Typical processing: Varies by project complexity. Contact PDS for current timeline estimates.
- 01 Create an account on the MyBuildingPermit.com portal.
- 02 Submit application online with required documents (Residential Building Application Checklist, structural plans, site plan, drainage plan, water/sewer approval if applicable).
- 03 Pay base application fee ($150) and plan check fee through the portal account.
- 04 Application reviewed for completeness by Planning and Development Services.
- 05 Technical review conducted by county staff.
- 06 Pay permit fee upon approval and receive permit issuance.
Typical processing time: Varies by project complexity. Contact PDS for current timeline estimates.
Fee schedule
Snohomish County building permit fees
Sample residential valuation rates: First floor $170.80/sq ft, Second/Third floor $170.80/sq ft, Unfinished basement/foundation $31.50/sq ft, Garage $69.64/sq ft, Carport/Covered deck $31.50/sq ft. 11% added for plumbing/mechanical fixtures on new construction. State surcharge $6.50 per permit. Technology surcharge 3% of permit fees. Access/Driveway permit $350 per county road connection. Site review fee $320. Critical area site plan review $250. School, park, and transportation impact fees apply (vary by project and location).
Required inspections
Scheduling and sequence
- MyBuildingPermit.com portal (online)
Typical sequence: Required inspections vary by project type. Typical sequence includes: foundation, framing, mechanical, plumbing, and final inspection. Approved plans must be on-site during inspections.
Frequently asked
Common questions about unincorporated Snohomish County permits
01 Do I need a building permit in unincorporated Snohomish County, WA? ▸
02 How much does a building permit cost in unincorporated Snohomish County, WA? ▸
03 How do I apply for a building permit in unincorporated Snohomish County, WA? ▸
04 How long does it take to get a building permit in unincorporated Snohomish County, WA? ▸
05 What work is exempt from building permits in unincorporated Snohomish County, WA? ▸
06 How do I schedule a building inspection in unincorporated Snohomish County, WA? ▸
Educational reference. Permit rules and fees change — confirm current requirements directly with Planning and Development Services (PDS) before applying. Jaspector is not legal advice.