Municipal GuideWashingtonSnohomish County · Unincorporated

Snohomish County Building Permit — Filed & Tracked For You

Your shed can be twice the size outside the urban growth area as inside it — the same county, the same code, a different line on a map.

Scope: Unincorporated Snohomish CountyCode route: State code, county amendmentsElectrical: State programme
Authority
Snohomish County Planning and Development ServicesUnincorporated areas only
Inside a growth area
Two hundred square feetShed and accessory exemption
Outside a growth area
Four hundred square feetThe same exemption, doubled
Repeat designs
Registered Basic PlansPre-approved and held on file

Snohomish County is the third most populous county in Washington, running from the Everett waterfront to the Cascade crest. Its permit exemption list contains the clearest illustration in this state of something no city guide can show you: the growth management boundary changing what you may build without a permit.

Planning and Development Services reviews and issues residential and commercial building permits, boundary line adjustments, subdivisions, driveway aprons, clearing and grading and other approvals, through its online permit portal.

This guide covers unincorporated Snohomish County. Everett and Marysville are incorporated and permit separately, and the county warns that many addresses reading as a city are in fact unincorporated — do not rely on the mailing address.

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The exemption threshold doubles outside the urban growth area. Single-storey sheds, playhouses, agricultural and similar structures not used for human habitation are exempt from a building permit up to two hundred square feet inside an urban growth area and four hundred square feet outside one. The same split applies to carports and patio covers not attached to a dwelling. Cities sit entirely inside growth areas, so this distinction only ever appears at county level.

What requires a building permit in Snohomish County?

Washington has a mandatory statewide building code. The codes enumerated in chapter 19.27 RCW, the State Building Code Act, are adopted and amended by the State Building Code Council within the Department of Enterprise Services, and they are required in all cities and counties — local government administers and enforces them rather than deciding whether to have them. A city or county may amend the state code, but it amends upward from a floor it cannot opt out of. So the question in Snohomish County is not whether a code applies, but which edition is in force and what Snohomish County Planning and Development Services has added to it.

Permit required

  • New buildings, additions, alterations and change of occupancy or use
  • Structural alterations, load-bearing changes, foundations, decks and retaining walls
  • Plumbing work under the Uniform Plumbing Code as adopted by the state
  • Mechanical and HVAC change-outs, fuel gas work and ventilation
  • Work affecting the Washington State Energy Code envelope or systems
  • Re-roofing above the exempt scope, demolition, and work in critical areas

Often exempt

  • Ordinary repairs and maintenance replacing materials in kind
  • Small accessory structures below the code threshold, where zoning allows
  • Painting, flooring, cabinetry and other finish work
  • Like-for-like fixture swaps with no alteration to piping

Local amendments, fee schedules and exempt thresholds differ from one jurisdiction to the next, so an exempt list from a neighbouring city is not reliable. An exemption from a building permit is never an exemption from zoning, critical areas review, the energy code or a trade permit. Confirm scope with Snohomish County Planning and Development Services before work starts.

Your electrical permit almost certainly does not come from the city. For most of Washington, electrical permits are issued and electrical inspections are carried out by the Electrical Program at the Department of Labour and Industries under chapter 296-46B WAC — not by the local building department. A minority of cities run their own electrical programme instead. Establish which applies to the parcel before you assume a single counter handles everything, because the electrical track runs on its own timetable and its own inspector.

The statewide features that catch projects everywhere

Four things shape a Washington filing more than the model code does. First, the edition is set by the state on a three-year cycle and adopted in two groups over a two-year timeline, so the building, residential, mechanical and plumbing parts do not all arrive on the same day. Second, plumbing runs on the Uniform Plumbing Code as adopted by the state, not the International Plumbing Code that most of the country uses. Third, the Washington State Energy Code is its own code under chapter 19.27A RCW rather than the international energy code, and it is among the most demanding in the country. Fourth, growth management and critical areas regulation reach ordinary residential work near wetlands, steep slopes, streams and shorelines far more often than owners expect. Cascadia subduction zone seismic detailing applies statewide. The county also runs a pre-approval scheme that shortens review on repeat designs: single family residences and duplexes can be built from pre-approved plans held on file, known as Registered Basic Plans for houses and Basics for duplexes, so a builder repeating a design across lots is not reviewed from scratch each time

⚠️ Confirm the edition in force and the electrical route, then permit before you build. Building without a required permit exposes the job to stop-work orders, penalties, correction orders and delayed occupancy — and in Washington it can also cost you lien rights, because courts have denied liens under chapter 60.04 RCW where the work was performed in violation of permit requirements.

Who handles permitting in Snohomish County?

Planning and Development Services reviews and issues building permits and land use applications for unincorporated Snohomish County, and maintains the current and historical development record for those areas including applications, site plans, house plans and permits.

Snohomish County permitting contact
DetailInformation
DepartmentSnohomish County Planning and Development Services
Address3000 Rockefeller Avenue, Everett, WA 98201
Phone(425) 388-3311
Counter hoursMonday to Friday 8:00 a.m. to 5:00 p.m., except Thursdays 10:00 a.m. to 5:00 p.m.
Sign-in cut-offsBy 3:30 p.m. for information consultations, by 4:00 p.m. for the Records Room
Records RoomClosed from noon to 1:00 p.m.
Records heldUnincorporated county only, organised by property tax account number
Utility coordinationCoordination with the public utility district may be required

Records sit strictly on the unincorporated side of the line. The department holds permit histories organised by property tax account number, land use files and permits for residential and commercial construction — but only for unincorporated Snohomish County. For a property inside a city’s limits the record is held by that city, and the department directs people to its map portal rather than to the address to establish which applies.

Even where a permit is not required, other approvals may still be. The county is explicit that being exempt from a building permit does not exempt a structure from setbacks, from other permit types or from other approvals — a hundred square foot shed may need no building permit and still have to meet siting rules.

Permit types

Residential permits

Residential permits cover single family residences and duplexes, whether custom designed or built from the pre-approved plan sets. Each project is assessed on its own design, size and configuration and on the property location, and environmental factors on a specific parcel may trigger additional requirements beyond the standard submittal.

How Washington contractor credentials work

Washington registers contractors rather than licensing them. Under chapter 18.27 RCW every contractor must register with the Department of Labour and Industries, file a continuous surety bond — thirty thousand dollars for a general contractor, fifteen thousand for a specialty contractor — and keep liability insurance on file. Registration runs for two years and carries no continuing education requirement at the base level. Crucially, registration is not a competence test and it does not authorise trade work: electrical work requires certification under chapter 19.28 RCW and plumbing under chapter 18.106 RCW, each with its own examination and its own programme office.

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A general registration does not let anyone touch the wiring or the pipes. A registered general contractor must subcontract electrical and plumbing work to appropriately certified trades, and an electrical contractor licence additionally requires at least one certified electrician on staff. Verify the registration is active and the bond and insurance current with Snohomish County Planning and Development Services and with the department, because registration lapses are common and an expired registration invalidates the credential the permit relies on.

Commercial permits

Commercial and multifamily permits run through the same portal, with the county fire marshal issuing seasonal burn restrictions for unincorporated areas that can affect site operations. Coordination with the public utility district may be required depending on the project.

Registrations, trade certifications and design professionals

Three credential layers appear on Washington projects: the state contractor registration under chapter 18.27 RCW, which nearly everyone doing the work needs; separate state trade certification for electricians and plumbers, each examined and administered by its own programme; and, on commercial and larger residential work, drawings stamped by a Washington-licensed architect or professional engineer. Confirm what Snohomish County Planning and Development Services requires for the specific building before filing.

Snohomish County permit costs and fees

Snohomish County fees follow the published schedule by permit type and valuation. Because electrical permits come from the state rather than the county, that cost is invoiced separately and does not appear on the county schedule.

How Snohomish County permit fees are structured
Fee componentHow it works
Building permitSet by the local jurisdiction, usually on project valuation; the state sets the code, not the fee
Plan reviewA percentage of the permit fee or a flat charge, set locally
Plumbing and mechanicalSeparate local permits under the adopted plumbing and mechanical codes
ElectricalUsually a state permit fee through the Labour and Industries Electrical Program, not a city fee
Energy codeCompliance documentation for the Washington State Energy Code, and review time for it
Critical areas and land useSeparate review and fees where wetlands, slopes, streams or shorelines are involved

Washington sets the code statewide but leaves the fee schedule local, so two jurisdictions on the same edition can price the same project very differently. The electrical fee is the one that most often surprises people, because on most projects it is paid to the state rather than to the city. Ask Snohomish County Planning and Development Services for the schedule in force on your filing date, and confirm the electrical route separately.

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Need a real number for a specific Snohomish County project? Send us the scope, address and valuation and we will identify the edition in force, the local amendments, the electrical route and the fee categories that will apply.

Trade permits and who may pull them

Trade permits are separate from the building permit and, in Washington, are not all issued by the same body. Plumbing and mechanical permits come from the local jurisdiction under the codes the state has adopted. Electrical permits come from the Electrical Program at the Department of Labour and Industries, unless this jurisdiction runs its own. That split is the single most common source of confusion on a Washington project.

Your electrical permit almost certainly does not come from the city. For most of Washington, electrical permits are issued and electrical inspections are carried out by the Electrical Program at the Department of Labour and Industries under chapter 296-46B WAC — not by the local building department. A minority of cities run their own electrical programme instead. Establish which applies to the parcel before you assume a single counter handles everything, because the electrical track runs on its own timetable and its own inspector.

  • Electrical work follows chapter 19.28 RCW and the state electrical rules at chapter 296-46B WAC, performed by a certified electrician working for a licensed electrical contractor.
  • Plumbing work follows the Uniform Plumbing Code as adopted by the state, performed by a plumber certified under chapter 18.106 RCW.
  • Mechanical and fuel gas work follows the state mechanical and fuel gas provisions, permitted locally.

Permit required

  • Service installations, panel upgrades, new circuits, solar PV and EV chargers
  • New plumbing, repipes, water heater change-outs, fixtures, backflow and gas piping
  • HVAC installation and change-out, ductwork, venting and commercial kitchen exhaust
  • Sprinkler, standpipe and fire alarm work on commercial and multi-family structures

Typically exempt

  • Replacing a fixture, switch, receptacle or light with no alteration to wiring or piping
  • Clearing a stoppage without replacing or rearranging concealed piping
  • Filter, thermostat and routine component service
  • Like-for-like appliance repair that does not alter the connection

How to apply for a Snohomish County building permit

1. Establish which side of the growth boundary you are on

It doubles the shed, carport and patio cover exemption thresholds from two hundred to four hundred square feet.

2. Do not trust the mailing address

Many addresses reading as a city are unincorporated; use the map portal to confirm.

3. Ask about registered basic plans

Pre-approved plan sets for houses and duplexes shorten review on repeat designs.

4. Remember exemption is not exemption from everything

An exempt structure still has to meet setbacks and may need other permits or approvals.

5. Plan the counter visit around Thursday

The counter opens at ten on Thursdays, with sign-in cut-offs at half past three and four.

6. Confirm the trade route

Electrical comes from the state programme rather than the county.

Review, corrections and what actually causes delay

In Washington the first cause of delay is the energy code, because the state code is its own instrument and more demanding than the international one most designers default to. After that comes critical areas review, which reaches ordinary residential work near wetlands, streams, steep slopes and shorelines and adds its own study and mitigation timeline. Then the electrical split, where a project waits on a city inspection that was never going to happen because the electrical permit sits with the state. Then edition confusion, because the state adopts in two groups and the parts do not all move together. Build review time into the schedule and confirm the checklist with Snohomish County Planning and Development Services before filing.

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Approvals do not stay live indefinitely. Permit validity periods are set locally on top of the state code, so they differ between neighbouring jurisdictions and cannot be assumed from a previous job. On phased or financed work, confirm the expiry window and keep the permit alive with progress inspections.

Inspections in Snohomish County

Where a permit is required, standard checkpoints include footing and foundation, framing, rough-in plumbing and mechanical, insulation and energy code compliance, fire systems on commercial work, and final, with a certificate of occupancy before the building is used. The county holds the development record only for unincorporated areas, so a due diligence search on a parcel near a city boundary has to start with the jurisdiction question.

The point to plan around is that the electrical inspections may be booked with a different body entirely. Where the state Electrical Program holds the electrical permit, its inspector attends on the state’s schedule and the local inspector will not sign off electrical work. Sequencing a cover-up around two independent inspection queues is the practical skill on a Washington job.

Do not cover work before the required inspection has been approved. Keep the issued permits — plural — the approved plans and the energy code documentation available on site.

Snohomish County permit search and official resources

Permit records in Washington are split the same way the permits are. Where Snohomish County Planning and Development Services is the authority for unincorporated Snohomish County, it holds the building, plumbing and mechanical records — but the electrical record for most projects sits with the state Electrical Program instead. If you are buying, refinancing or renovating, check both, because a clean local record does not mean the electrical work was ever permitted.

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Confirm the edition, the local amendments and the electrical route. Washington sets a mandatory statewide minimum under chapter 19.27 RCW, but the edition moves in two groups on a three-year cycle and every jurisdiction may amend upward. All three questions have to be answered for the parcel and the filing date.

These are the primary sources behind this guide. Codes, fee schedules and procedures change — confirm the position for your filing date.

Frequently asked questions

How big a shed can I build without a permit?

It depends which side of the urban growth area boundary you are on. Single-storey sheds, playhouses, agricultural and similar structures not used for human habitation are exempt up to two hundred square feet inside an urban growth area and four hundred square feet outside one, with a roof overhang allowance on top.

Does that apply to carports too?

Yes. Carports and patio covers not attached to a dwelling follow the same split, exempt up to two hundred square feet inside a growth area and four hundred square feet outside one.

If my shed is exempt, am I finished?

No. The county is explicit that being exempt from a building permit does not exempt the structure from setbacks or from other permit types and approvals that may still be required.

Am I actually in the county?

Check rather than assume. Many addresses that read as a city are in fact unincorporated, and the county directs people to its map portal rather than the mailing address to establish which jurisdiction applies.

Which code edition applies?

The state edition as amended by the county. Washington has a mandatory statewide building code. The codes enumerated in chapter 19.27 RCW, the State Building Code Act, are adopted and amended by the State Building Code Council within the Department of Enterprise Services and are required in all cities and counties, so local government administers and enforces them rather than choosing whether to have them. The two thousand twenty-one editions took effect on the fifteenth of March, two thousand twenty-four after two delays, and the two thousand twenty-four editions are dated to take effect on the third of May, two thousand twenty-seven. Adoption runs in two groups over a two-year timeline, so the building, residential, mechanical and plumbing parts do not all move on the same day. A city or county may amend upward from the state minimum but cannot opt out of it.

Who registers my contractor?

The state. Washington registers contractors rather than licensing them. Under chapter 18.27 RCW a contractor registers with the Department of Labour and Industries, files a continuous surety bond of thirty thousand dollars as a general contractor or fifteen thousand as a specialty contractor, and keeps liability insurance on file, renewing every two years. Registration is not a competence test and does not authorise trade work: electrical certification comes under chapter 19.28 RCW and plumbing under chapter 18.106 RCW. The electrical permit itself usually comes from the state rather than the city, because the Electrical Program at Labour and Industries issues electrical permits and carries out electrical inspections for most of Washington under chapter 296-46B WAC.

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  • Twenty-two years of filing, so the edition and the electrical route are settled before submission
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  • State contractor registration, bond and insurance verified as active before filing
  • Energy code and critical areas documentation prepared rather than discovered in review
  • Two inspection queues sequenced so a cover-up never waits on the wrong inspector

Alliance Permitting is a permit documentation and submission company in Washington. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.

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This guide is provided by Alliance Permitting for general information about Snohomish County permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.

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