Building permits in King County, Washington
Of the 10 common home projects we have verified in King County, 3 need a permit outright and 6 depend on size or scope. Click any project for the full rule, fee, and how to apply.
By Mario Bailey Last checked · 2 official sources
Verified against official sources- Project types verified
- 10
- in King County
One thing King County does not make you permit
Worth knowing before you call anyone. Most jurisdictions we cover require all of these.
- Roof Replacement Permit
Replacement of roofing or siding on a detached one or two-family house in unincorporated King County does not require a building permit
King County Department of Local Services Permitting Division
- 919 SW Grady Way Suite 300, Renton, WA 98057
- Phone: (206) 296-6600
- Email: PermitQuestions@kingcounty.gov
- Official permit page
- Permit portal
- Official fee schedule
Look up a permit in King County
King County runs an online permit portal. Many local portals let you check application status, search permit records, and view inspection results without calling the office.
Search the King County permit portal
What needs a permit in King County
Of the 10 common home projects we have verified in King County, 3 need a permit outright and 6 depend on size or scope. Click any project for the full rule, fee, and how to apply.
| Project | Permit needed? | Threshold | Typical fee |
|---|---|---|---|
| Deck Permit | It depends | uncovered decks 30 inches or less above ground do not require a building permit in unincorporated King County; decks over 30 inches above grade require a permit | Most permit fees increased approximately 14% on January 1 2026 plus a $126 application... |
| Electrical Permit | Permit required | Any size | ...(effective 7/1/2026): new single or two family home wiring starts at $119.90 for... |
| Fence Permit | It depends | fences 6 feet or less do not require a building permit in unincorporated King County; fences over 6 feet require a permit | Most permit fees increased approximately 14% on January 1 2026 plus a $126 application... |
| HVAC Permit | Permit required | Any size | Mechanical installation-only permit is a flat $183 inspection fee covering up to six... |
| Patio Permit | It depends | at-grade patios and uncovered decks 30 inches or less above ground are exempt; covered patios and taller structures require a building permit | ...(which the county states includes porches or decks of any size) applies, $772... |
| Plumbing Permit | Permit required | Any size | the plumbing and backflow permit fee is $137 plus $27 per fixture, effective 1/1/2026 |
| Pool Permit | It depends | prefabricated above-ground pools less than 24 inches deep and not exceeding 5000 gallons are exempt; all other pools require a building permit in unincorporated King County | Most permit fees increased approximately 14% on January 1 2026 plus a $126 application... |
| Roof Replacement Permit | No permit needed | Exempt | Most permit fees increased approximately 14% on January 1 2026 plus a $126 application... |
| Shed Permit | It depends | storage sheds 200 sq ft or less as accessory to a residential house do not require a building permit in unincorporated King County; sheds over 200 sq ft require a permit | Most permit fees increased approximately 14% on January 1 2026 plus a $126 application... |
| Solar Permit | It depends | roof-mounted solar PV panels weighing less than 4 pounds per square foot on residences do not require a building permit; heavier installations require a permit | Most permit fees increased approximately 14% on January 1 2026 plus a $126 application... |
What you can build in King County
- Shed size, height and setback rules in King County (4 rules, each quoted from an official King County source)
- Fence size, height and setback rules in King County (5 rules, each quoted from an official King County source)
- Deck size, height and setback rules in King County (2 rules, each quoted from an official King County source)
- Pool size, height and setback rules in King County (1 rule, each quoted from an official King County source)
Planning a project in King County?
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King County permit fees compared with nearby Washington localities
| Washington locality | Deck Permit | HVAC Permit | Electrical Permit |
|---|---|---|---|
| King County | ...approximately 14% on January 1 2026 plus a $126... | Mechanical installation-only permit is a flat $183... | ...single or two family home wiring starts at $119.90... |
| Bellevue | ...fee by valuation per Table 4 of Ordinance 6879, $44... | ...8 of Ordinance 6879: furnace up to 100,000 BTU $59... | ...fee by valuation per Table 6 of Ordinance 6879, $79... |
| Clark County | See schedule | Application rev 1.30.23: $94 issuance plus per-appliance... | See schedule |
| Pierce County | ...PCC Table 17C.10-1-B (valuation based): $69.00 for... | Issue each mechanical permit fee $58.00, plus unit fees... | See schedule |
Each cell is the opening clause of that Washington jurisdiction's own fee schedule; the full wording and source sit on each permit page.
King County permit questions, answered from the data
- Do you need a permit in King County?
- For most projects, yes. Of the 10 permit types we have verified for King County, 3 always require a permit (for example an electrical permit), 6 depend on size or scope (a deck permit, for instance), and 1 needs no permit at all in King County. Each King County permit type's page states the exact rule and its source.
- How much does a permit cost in King County?
- King County publishes a fee for 10 of the 10 permit types we cover, each quoted on its page from the jurisdiction's own schedule (linked on every page that carries one). Fees are set by King County Department of Local Services Permitting Division; we do not estimate or mark them up.
- Where do you apply for a permit in King County?
- King County Department of Local Services Permitting Division issues permits in King County, with an online portal for applications, plan uploads and status checks, and takes questions at (206) 296-6600. The King County official page and portal are linked in the office section above.
How the King County pages were verified. 10 permit types, 5 distinct official sources, most recently checked . Every rule is read from King County Department of Local Services Permitting Division or the applicable code and cited on its page; anything we could not confirm for King County is marked rather than estimated. How we verify.
Permitting activity in King County
In 2025, King County authorized permits for 8,505 new residential housing units (2,510 single-family, 5,995 in multi-family buildings), valued at $2.5B , down from 10,564 the year before. That works out to about 3.6 permits per 1,000 residents. It is a useful gauge of how busy the local permit office is.
Source: U.S. Census Bureau, Building Permits Survey, 2025 annual data · population 2,344,939.
About King County
King County has about 988,330 housing units. The median home is valued at $811,200, against a median household income of $122,148. About 56% of homes are owner-occupied, and the typical home was built around 1983. Older housing stock usually means more renovation, electrical, and plumbing permits.
Source: U.S. Census Bureau, American Community Survey 2023 5-year.