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.
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 200 square feet inside an urban growth area and 400 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 make the state code stricter but cannot opt out of it, and local changes affecting houses or apartments need State Building Code Council approval. 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
Short on time to read all of this?
Get a free quote →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.
Local rules worth knowing
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
Washington has a mandatory statewide building code under chapter 19.27 RCW that every city and county enforces and may make stricter; electrical permits come from the Department of Labor and Industries unless the city runs its own programme or Tacoma Power serves the site. Building codes in Washington
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.
| Detail | Information |
|---|---|
| Department | Snohomish County Planning and Development Services |
| Address | Administration West Building, second floor, 3000 Rockefeller Avenue, Everett, WA 98201 |
| Phone | (425) 388-3311 |
| Counter hours | Monday 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-offs | By 3:30 p.m. for information consultations, by 4:00 p.m. for the Records Room |
| Records Room | Closed from noon to 1:00 p.m. |
| Records held | Unincorporated county only, organised by property tax account number |
| Utility coordination | Coordination 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 — 100 square foot shed may need no building permit and still have to meet siting rules.
In 2025, building permits issued in unincorporated Snohomish County authorized 1,162 new privately owned housing units, 1,024 of them single-family homes, according to the U.S. Census Bureau Building Permits Survey.
Permit types
Not sure this scope needs a permit?
Get a free quote →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
A general registration does not let anyone touch the wiring or the pipes. A general contractor needs a licensed electrical contractor and a licensed plumbing contractor for that work, or must hold those licences itself, and each electrical contractor must name a master electrician or a certified administrator. Owners may do their own electrical and plumbing work on their own property, with limits for buildings meant for sale or rent. 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.
Most Washington contractors register with the Department of Labor and Industries (with a surety bond and insurance) rather than holding a licence; electrical and plumbing contractors also need an L&I contractor licence. Contractor licensing in Washington
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.
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 it is paid to L&I rather than with the building permit. Ask Snohomish County Planning and Development Services for the schedule in force on your filing date, and confirm the electrical route separately.
Rather talk it over?
Call 1-855-478-4290 →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.
Fees are set locally, plus a small state permit fee (RCW 19.27.085); the electrical fee goes to whichever body issues the electrical permit. Permit fees in Washington
Trade permits and who may pull them
Permit required
- Service installations, panel upgrades, new circuits, solar PV and EV chargers
- New plumbing, repipes, water heater change-outs, fixtures and backflow, plus gas piping (usually on a mechanical or gas permit)
- 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
Plumbing and mechanical permits are local; electrical permits come from the Department of Labor and Industries unless the city runs its own electrical programme or Tacoma Power serves the site. Trade permits in Washington
How to apply for a Snohomish County building permit
It doubles the shed, carport and patio cover exemption thresholds from 200 to 400 square feet.
Many addresses reading as a city are unincorporated; use the map portal to confirm.
Pre-approved plan sets for houses and duplexes shorten review on repeat designs.
An exempt structure still has to meet setbacks and may need other permits or approvals.
The counter opens at 10 on Thursdays, with sign-in cut-offs at half past three and four.
Electrical comes from the state programme rather than the county.
Rather not deal with the Snohomish County building department?
Get a free quote →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 local inspection that was never going to happen because the electrical permit sits with L&I. Then edition confusion around the switch-over date, when a new state edition takes effect and local amendments change with it. Build review time into the schedule and confirm the checklist with Snohomish County Planning and Development Services before filing.
The state code sets a 180-day default for permit validity, but Snohomish County may change it, so confirm the expiry on phased or delayed work. Permit validity in Washington
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. Because L&I holds the electrical permit here, 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 — while the electrical record sits with the state Department of Labor and Industries (L&I), which issues the electrical permits and carries out the electrical inspections here. If you are buying, refinancing or renovating, check both, because a clean local record does not mean the electrical work was ever permitted.
Want this handled start to finish?
Get a free quote →Confirm the edition, the local amendments and the electrical route. Washington sets a mandatory statewide minimum under chapter 19.27 RCW, the edition changes on a three-year cycle, and every jurisdiction may make it stricter. 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.
- Snohomish County permitting
- Snohomish County residential building permits
- Snohomish County Planning and Development Services
- Labor and Industries contractor laws and rules
- Washington State Building Code Council
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 200 square feet inside an urban growth area and 400 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 200 square feet inside a growth area and 400 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.
Inspections are where schedules slip.
Get a free quote →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 2021 editions took effect on the fifteenth of March, 2024 after two delays, and the 2024 editions are dated to take effect on the third of May, 2027. The state adopts a new edition every three years and reviews the codes in two groups, but all of them take effect on the same date (the 2021 codes on 15 March 2024, the 2024 codes on 3 May 2027). A city or county may make the state code stricter but cannot opt out of it; local changes affecting houses or apartments need State Building Code Council approval, and the residential energy code cannot be changed locally.
Who registers my contractor?
The state. Most Washington contractors register rather than hold a licence; electrical and plumbing contractors must also hold an L&I contractor licence. Under chapter 18.27 RCW a contractor registers with the Department of Labor and Industries, files a continuous surety bond of $30,000 as a general contractor or $15,000 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 comes from the state, because the Electrical Program at the Department of Labor and Industries (L&I) issues electrical permits and carries out electrical inspections here under chapter 296-46B WAC.
Simplify Snohomish County permitting with Alliance Permitting
A growth boundary that doubles what you may build unpermitted is the kind of thing worth checking before the shed is ordered, not after.
Trusted by leading builders, developers, and national contractors — 21+ years of filing in the jurisdictions we write about.
Contractors and builders choose Alliance for Snohomish County because the work is done by people who have stood at the counter:
- 21+ years of filing, so the edition and the electrical route are settled before submission
- We confirm which state code group governs each part of the work on your filing date
- 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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More Washington permitting guides
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.