Washington permit requirements
We have read and dated 80 permit rules across 8 jurisdictions in Washington. They do not all say the same thing: shed thresholds alone run from 120 to 200 sq ft across 8 of them.
- Jurisdictions
- 8
- Verified rules
- 80
- Permit always required
- 28
- Depends on the project
- 48
Do you need a building permit in Washington?
Usually it depends on the size of the job, and the size that decides it is not set by Washington: permits are issued by the city or county, not the state, so the rule that governs your project is the one your own jurisdiction publishes. 28 of those local rules require a permit outright, 48 depend on a size or scope condition the office publishes, and 4 need none. Washington sets the building code those local rules derive from; your city or county sets the threshold and the fee.
Recent rule changes in Washington
Effective January 1, 2026, Bellevue, Washington charges a flat $290 issuance fee for standard re-roof permits under Ordinance 6879, its 2026 development services fee schedule.
Bellevue, WA · Ord. 6879 · published
How permitting works in Washington
By Mario Bailey Last checked · 11 official sources
Who writes the code, and who enforces it
Washington’s residential code is the Washington State Residential Code, part of the Washington State Building Code, based on the International Residential Code with Washington amendments. The Washington State Building Code Council (SBCC) adopts it; the 2021 code took effect March 15, 2024. Local jurisdictions enforce it and may adopt limited amendments.
What the state sets
Two rules reach every Washington address. RCW 18.27.090(12) exempts anyone working on property they own from state contractor registration, unless meant to sell, demolish, or lease it. RCW 19.28 makes electrical licensing a state matter under L&I, which issues most permits; RCW 19.28.141 exempts a city enforcing an equal-or-stricter ordinance, and Seattle, Bellevue, and Tacoma issue their own. RCW 19.28.261 lets you wire your own residence, farm, or place of business without an electrician’s license, unless it is new construction for rent, sale, or lease (an owner in one of up to four new units may apply by affidavit), or the property is offered for sale within 12 months of obtaining it.
What your county or city decides
Counties and cities enforce the state code (RCW 19.27.050), may charge their own fees (RCW 19.27.100), and may amend it, though a residential amendment needs Council approval (RCW 19.27.060). That is why the 8 jurisdictions we track differ: a permit-free deck must stay at or under 18 inches in Seattle and 30 inches elsewhere, and Clark County and Tacoma also exempt only freestanding decks of 200 square feet or less. See what you can build without a permit in Washington for the comparison.
If work was done without a permit
Washington has no statewide fine for building without a permit; counties and cities enforce the code under RCW 19.27.050, so stop work orders and fines come from local ordinance. Where L&I issues the permit, unpermitted electrical work costs $250 for a first offense, $1,000 for a second, $2,000 after, and L&I may double a scheduled penalty for a serious violation, capped at $10,000 (WAC 296-46B-915, including (11)). Plumbing trade work without the required certificate is a separate infraction: $100 minimum for an individual’s first infraction, $500 for a contractor’s, up to $5,000 for a later one (RCW 18.106.020, 18.106.270). There is no statewide after-the-fact building permit program; whether unpermitted building work can be legalized is a local decision. See building without a permit in Washington for citations.
- Washington State Building Code Council (SBCC), home page and the current 2021 code adoption cycle, read
- SBCC Residential Code Amendments page, the 2021 Washington State Residential Code and its March 15, 2024 effective date, read
- WAC 296-46B-915, the L&I civil penalty schedule for electrical work, including subsection (11) on unpermitted work, read
- RCW 19.27.050, delegating state building code enforcement to counties and cities, read
- RCW 19.27.100, letting a city, town, or county impose its own permitting fees, read
- RCW 19.27.060(1)(a), the Council-approval requirement for a local residential code amendment, read
- RCW 19.28.261, the owner exemption from electrician licensing, including the four-unit owner-occupant affidavit exception in subsection (1), read
- RCW 19.28.141(1): "the provisions of RCW 19.28.101 shall not apply: (a) Within the corporate limits of any incorporated city or town which has heretofore adopted and enforced or subsequently adopts and enforces an ordinance requiring an equal, higher or better standard..."; the exemption that lets Seattle, Bellevue, and Tacoma run their own electrical permitting, read
- RCW 18.27.090, contractor registration exemptions: subsection (12) for an owner working on their own property, subsection (11) for an owner who hires a registered contractor, read
- RCW 18.106.020, the plumbing certificate requirement and infraction for violating it, read
- RCW 18.106.270, the monetary penalty amounts for a plumbing infraction, read
Do Washington jurisdictions agree?
Every row below is a measurement at least two Washington jurisdictions publish, compared against each other. This is the question a statewide answer cannot settle, because the number that governs your project is the one your own city or county publishes.
| Project | Published threshold | Jurisdictions | Agreement |
|---|---|---|---|
| Shed | 120 to 200 sq ft | 8 | 2 different numbers |
| Deck | 18 to 30 inches | 7 | 2 different numbers |
| Fence | 6 to 8 feet | 8 | 3 different numbers |
| Solar | 3.5 to 4 lbs per sq ft | 3 | 2 different numbers |
| Pool | 24 inches | 7 | Same number in all 7 |
| Patio | 30 inches | 2 | Same number in all 2 |
2 of 6 comparable measurements are uniform across Washington; 4 are not. Latest verification 2026-07-19.
Where Washington jurisdictions split
The verdict for each project across the 8 Washington jurisdictions we cover. On 6 of 10 projects they do not give the same answer, which is why a statewide answer is not one.
| Project | Permit required | Depends | No permit | Across the state |
|---|---|---|---|---|
| HVAC | 7 | 1 | Answer varies | |
| Patio | 6 | 2 | Answer varies | |
| Plumbing | 7 | 1 | Answer varies | |
| Pool | 1 | 7 | Answer varies | |
| Roof Replacement | 1 | 5 | 2 | Answer varies |
| Solar | 4 | 4 | Answer varies | |
| Deck | 8 | Same answer everywhere | ||
| Electrical | 8 | Same answer everywhere | ||
| Fence | 8 | Same answer everywhere | ||
| Shed | 8 | Same answer everywhere |
Building without a permit in Washington
Washington has no statewide fine for building without a building permit. The State Building Code Act, RCW 19.27, hands enforcement to local government: RCW 19.27.050 requires the state building code to be enforced by counties and cities, so stop work orders and fines for unpermitted construction come from your city or county ordinance, not from a state statute.
Penalties, the as-built path, and what the statute actually says
What you can build without a permit in Washington
4 of the 80 answered rules across Washington need no permit at all and 48 turn on a size or scope condition the jurisdiction publishes, by project and jurisdiction, in each office's own words.
What a permit costs in Washington
There is no single Washington permit fee. Each jurisdiction in Washington sets and publishes its own, and they do not use the same pricing model, so the figure that applies to your project is the one your own city or county publishes. Below is every Washington project where we have quoted one, verbatim, from the office's own schedule.
| Project in Washington | Jurisdictions publishing a fee |
|---|---|
| HVAC | 7 |
| Roof Replacement | 7 |
| Fence | 6 |
| Plumbing | 6 |
| Pool | 6 |
| Shed | 6 |
| Solar | 6 |
| Deck | 5 |
| Patio | 5 |
| Electrical | 3 |
Each row links to the Washington table carrying every quoted fee, its source and its verification date. We do not publish a Washington average: the notes mix flat minimums, valuation percentages and per-fixture charges, so an average would be a number no office charges.
Building code in Washington
Washington State Residential Code (part of the Washington State Building Code). Based on the International Residential Code (IRC), with Washington amendments.
Administered by Washington State Building Code Council (SBCC). Official source
Local jurisdictions enforce the state code and may adopt limited amendments.
Most local permit thresholds derive from this code. See our sources and standards.
What each Washington jurisdiction publishes
One line per jurisdiction, written from its own rules rather than from a state summary. This is the section that used to be a list of links, and the states with the fewest jurisdictions to compare are the ones it says the most about.
- Bellevue 10 rules
9 of 10 projects need a permit, and 1 does not. Only electrical and HVAC work always needs one. No permit at all for patio. Published thresholds include deck at 30 inches and fence at 8 feet.
- Clark County 10 rules
5 of 10 projects always need a permit and 5 turn on the size or scope of the work. The ones that depend on the project are deck, fence, patio, pool and shed. Published thresholds include fence at 7 feet and deck at 30 inches.
- King County 10 rules
9 of 10 projects need a permit, and 1 does not. Only electrical, HVAC and plumbing work always needs one. No permit at all for roof replacement. Published thresholds include fence at 6 feet and solar at 4 lbs per sq ft.
- Pierce County 10 rules
4 of 10 projects always need a permit and 6 turn on the size or scope of the work. Published thresholds include fence at 6 feet and deck at 30 inches.
- Seattle 10 rules
8 of 10 projects need a permit, and 2 do not. The ones that depend on the project are deck, fence and shed. No permit at all for patio and roof replacement. Published thresholds include deck at 18 inches and shed at 120 sq ft.
- Snohomish County 10 rules
3 of 10 projects always need a permit and 7 turn on the size or scope of the work. Only electrical, HVAC and plumbing work always needs one. Published thresholds include deck at 30 inches and fence at 8 feet.
- Tacoma 10 rules
4 of 10 projects always need a permit and 6 turn on the size or scope of the work. Published thresholds include fence at 7 feet and deck at 200 sq ft.
- Thurston County 10 rules
2 of 10 projects always need a permit and 8 turn on the size or scope of the work. Only electrical and plumbing work always needs one. Published thresholds include deck at 30 inches and fence at 8 feet.