Snohomish County, WA Building Safety: Building Permits (2026)
Key Facts
- Governing section
- SCC 30.50.406
- Application form
- Written, filed with building official
- Fee timing
- Due before permit is valid
- Permit expiration
- 18 months after issuance
- Extension allowed
- One, up to 18 more months
- Work-before-permit penalty
- Investigation penalty, SCC 30.86.400(9)
- Issuing department
- Planning and Development Services
Summary
Any owner who intends to build, enlarge, alter, repair, move, demolish, or change the occupancy of a structure in unincorporated Snohomish County must first apply to the building official and obtain a permit before work starts. Gas, mechanical, and plumbing system changes trigger the same requirement.
Any owner or owner's authorized agent who intends to construct, enlarge, alter, repair, move, demolish or change the occupancy of a building or structure, or to erect, install, enlarge, alter, repair, remove, convert or replace any gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be performed, shall first make application to the building official and obtain the required permit.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through legislation passed August 12, 2026).
Full Breakdown
406 sets the trigger for residential work: any owner or authorized agent who intends to construct, enlarge, alter, repair, move, demolish or change the occupancy of a building, or to install, alter, remove, convert or replace a gas, mechanical or plumbing system regulated by the code, must first make application to the building official and obtain the required permit before doing or causing that work. 102. 144). 103 exempts specific categories of minor work, such as one-story detached accessory structures under 200 square feet in an urban growth area, sidewalks, driveways, and painting or similar finish work, though flood hazard or critical area rules can still apply to exempt work. 400(9), on top of the standard permit fees.
Violations & Fines
Beginning construction, alteration, or system work before the permit is issued draws an investigation penalty under SCC 30.86.400(9) in addition to the regular permit fee (SCC 30.50.162). The building official can also suspend or revoke an issued permit under SCC 30.85.300 or 30.85.310 (SCC 30.50.146), and a permit never authorizes work that otherwise violates the construction codes or another county ordinance (SCC 30.50.142).
Frequently Asked Questions
Do I need a permit to remodel or repair my house in unincorporated Snohomish County?
How long is a Snohomish County building permit good for?
What happens if I start work before my permit is issued?
Is any home project exempt from a building permit?
Sources & Official References
Other rules in Snohomish County
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