Pool Permit in King County, Washington
It depends
Sometimes, depending on the project
Before constructing any pool except small exempt above-ground units in unincorporated King County
Issued byKing County Department of Local Services Permitting Division
By Mario Bailey, verified against official sources
Quick answer
In unincorporated King County a building permit is required for most swimming pool installations. Prefabricated above-ground pools less than 24 inches deep and not exceeding 5,000 gallons are exempt from the permit requirement. All in-ground pools and larger above-ground pools require a building permit through MyBuildingPermit.com. These rules apply to unincorporated King County only.
Typical threshold: 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.
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When a permit is usually needed
Before constructing any pool except small exempt above-ground units in unincorporated King County
What your pool permit must meet in Washington
Washington's 2021 Residential Code (WAC 51-51, effective statewide March 15, 2024) requires backyard swimming pools, spas, and hot tubs at single-family and duplex homes to be designed and built to the 2021 International Swimming Pool and Spa Code, incorporated by direct statewide reference rather than left to local option.
- The design and construction of swimming pools, spas, and other aquatic recreation facilities must comply with the 2021 International Swimming Pool and Spa Code whenever the facility falls into one of three defined residential categories (WAC 51-51-0327).
- That mandatory ISPSC standard covers pools for the sole use of a single-family dwelling's residents and guests, the sole use of a resident-owned duplex, or a facility used exclusively for medical physical therapy under a licensed practitioner's supervision (WAC 51-51-0327).
- Any other water recreation facility outside those residential categories is regulated under separate Washington Department of Health rules, not the Residential Code (WAC 246-260; WAC 51-50-3109).
Based on 2021 International Swimming Pool and Spa Code (ISPSC), incorporated by WAC 51-51-0327 into the 2021 Washington State Residential Code. Read the code. Local amendments can be stricter; confirm the current requirement with your office before you build.
What a pool permit costs in King County
How King County compares in Washington
| Jurisdiction | Permit needed? | Threshold |
|---|---|---|
| Bellevue | It depends | swimming pools over 24 inches deep require a permit with plan review; above-ground pools 24 inches or less may be exempt |
| Clark County | It depends | A permit is required for any structure intended for swimming or recreational bathing that contains water over 24 inches deep, including in-ground, aboveground and on-ground pools, hot tubs and spas. |
| King Countythis page | 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 |
| Pierce County | It depends | Prefabricated swimming pools accessory to a single family residence (Group R-3 occupancy) are exempt if less than 24 inches deep, with no separate gallon volume cap; in-ground pools and pools 24 inches deep or deeper require a building permit. Self-contained spas and hot tubs installed entirely above ground and not connected to the potable water system or a septic or sewer drain are separately exempt regardless of depth. |
| Snohomish County | It depends | prefabricated swimming pools regulated under the IRC (one- and two-family dwellings) exempt if less than 24 inches deep, with no gallon-volume cap; in-ground pools or pools 24 inches deep or more require a building permit |
| Tacoma | It depends | prefabricated above-ground pools less than 24 inches deep and not greater than 5000 gallons are exempt; all other pools require a building permit |
| Thurston County | It depends | Pools are exempt only if prefabricated, entirely above ground, less than 24 inches deep, and under 5,000 gallons capacity. |
Closest pool permit thresholds outside Washington
Jurisdictions we cover whose limit sits nearest King County's 24 inches.
- Brevard County, Florida, Permits are issued for in-ground pools and spas, and for above-ground pools with a depth of 24 inches or greater.
- Charlotte County, Florida, This residential pool/spa permit type includes spas, swim spas, and above-ground pools that are 24 inches or greater in depth.
- Hernando County, Florida, Manufactured pools less than 24 inches deep are exempt from a building permit
- Lee County, Florida, All in-ground pool construction or renovation requires a permit; an above-ground pool requires a permit when its water depth is 24 inches or more.
How to apply in King County
In King County, a residential pool permit application covers both construction and safety: a scaled site plan, structural plans for the pool, a barrier plan showing how the pool will be enclosed, and an electrical plan covering bonding and the equipment disconnect.
What most pool permit applications include:
- Pool and spa design and construction fall under the residential code chapter that folds in the swimming pool and spa code, and permit review checks plans against that chapter (IRC R326).
- For King County, the site plan must show pool equipment such as pumps, filters, and heaters set back at least 36 inches from the outside of the required barrier (ISPSC 305.2.9).
- For an in-ground pool, engineered structural plans covering the shell and reinforcing steel, with the responsible structural engineer's license information, are a standard part of the submittal (per official pool submittal checklists).
- For King County, a barrier plan identifying the fence, pool structure, or dwelling wall that will enclose the pool must be submitted and must comply with the code's barrier chapter (ISPSC 305).
- Electrical plans must show the pool's equipotential bonding design, since the shell, perimeter surfaces, and metal fittings within 5 feet of the water must all tie into a common bonding grid (NEC 680.26).
- For King County, the electrical plan must also show a disconnecting means for the pool equipment that is readily accessible and within sight of the equipment (NEC 680.13).
General submittal guidance from 2021 IRC R326 (adopting the ISPSC), ISPSC 2021 Section 305, and NEC 2020 Article 680. Source. King County Department of Local Services Permitting Division sets the exact checklist for King County.
Where to apply in King County:
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
Pool Permit in King County compared with nearby Washington localities
| Locality | Permit needed? | Threshold | What each Washington schedule says | Verified |
|---|---|---|---|---|
| King County | 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... | |
| Bellevue | It depends | swimming pools over 24 inches deep require a permit with plan review; above-ground pools 24 inches or less may be exempt | Pool equipment electrical inspection fee of $94 without plan review per Table 7 of... | |
| Clark County | It depends | A permit is required for any structure intended for swimming or recreational bathing that contains water over 24 inches deep, including in-ground, aboveground and on-ground pools, hot tubs and spas. | Fees are established by county ordinance and calculated automatically during the... | |
| Pierce County | It depends | Prefabricated swimming pools accessory to a single family residence (Group R-3 occupancy) are exempt if less than 24 inches deep, with no separate gallon volume cap; in-ground pools and pools 24 inches deep or deeper require a building permit. Self-contained spas and hot tubs installed entirely above ground and not connected to the potable water system or a septic or sewer drain are separately exempt regardless of depth. | Where a permit is required: in-ground pool permit $230.00 | |
| Seattle | Permit required | Not specified | An unenclosed pool accessory to a single-family or duplex home is a flat fee of four... |
Inspections and closing out your permit
In King County, pool inspections track the concrete pour: the steel and bonding grid are checked before gunite or shotcrete goes in, bonding is checked again before decking is poured, and the permanent barrier and remaining electrical work are checked at final before the pool can be filled and used.
- In King County: before gunite or shotcrete is sprayed, the inspector checks the rebar against the engineered plans and confirms the equipotential bonding wire is stubbed out and tied into the steel, since it will be buried in concrete afterward (NEC 680.26).
- In King County: a bonding inspection separately confirms coping, decking, ladders, handrail cups, and any other metal within 5 feet of the water are tied to the bonding grid, and it must pass before coping is installed (NEC 680.26).
- In King County: a temporary barrier at least 4 feet high must enclose the site from the moment excavation starts until the permanent barrier is finished, and inspectors check for it throughout construction (ISPSC 305.1.1).
- In King County: a pre-plaster inspection confirms the circulation equipment's electrical work is installed and all bonding is complete before the pool's interior finish goes on (NEC 680.26).
- In King County: at final inspection the permanent barrier is checked against the code's requirements and the equipment and cover-mechanism bonding must be complete before the pool can be filled and used (ISPSC 305, NEC 680.26).
Schedule each inspection in advance and pass the final before you use the work or close the permit. Request inspections through the King County permit portal or by phone at (206) 296-6600.
Inspection sequence from NEC 2020 Article 680.26 (equipotential bonding) and ISPSC 2021 Section 305 (barriers). Source. An open permit left un-inspected can surface later in a title search or home sale.
Your Pool Permit checklist for King County
- Confirm the requirement. Sometimes, depending on the project. Typical threshold: 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. Usually needed: Before constructing any pool except small exempt above-ground units in unincorporated King County.
- Budget the fee. Most permit fees increased approximately 14% on January 1 2026 plus a $126 application screening fee. Official fee schedule.
- Apply. In King County, a residential pool permit application covers both construction and safety: a scaled site plan, structural plans for the pool, a barrier plan showing how the pool will be enclosed, and an electrical plan covering bonding and the equipment disconnect. Start at the King County permit portal.
- Keep the office details handy. King County Department of Local Services Permitting Division. Phone: (206) 296-6600. Address: 919 SW Grady Way Suite 300, Renton, WA 98057.
- Plan for inspections. In King County, pool inspections track the concrete pour: the steel and bonding grid are checked before gunite or shotcrete goes in, bonding is checked again before decking is poured, and the permanent barrier and remaining electrical work are checked at final before the pool can be filled and used.
Compiled from the official sources on this page. Last checked .
Permitting activity in King County
In 2024, King County authorized permits for 10,564 new residential housing units (2,352 single-family, 8,212 in multi-family buildings), valued at $2.7B, down from 10,601 the year before. That works out to about 4.5 permits per 1,000 residents.
Source: U.S. Census Bureau, Building Permits Survey, 2024 annual data · population 2,340,211.
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.
Source: U.S. Census Bureau, American Community Survey 2023 5-year.
Frequently asked questions
- Do you need a pool permit in King County?
- In unincorporated King County a building permit is required for most swimming pool installations. Prefabricated above-ground pools less than 24 inches deep and not exceeding 5,000 gallons are exempt from the permit requirement. All in-ground pools and larger above-ground pools require a building permit through MyBuildingPermit.com. These rules apply to unincorporated King County only. 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. Always confirm with the office before starting.
- How much does a pool permit cost in King County?
- Most permit fees increased approximately 14% on January 1 2026 plus a $126 application screening fee. See the official fee schedule for current amounts.
- Where do you apply for a pool permit in King County?
- You can apply through the King County permit portal or contact the King County Department of Local Services Permitting Division directly. The links are listed on this page.
- Can a homeowner pull a pool permit themselves in King County?
- Under Washington law (RCW 18.27.090(11), (12); RCW 19.28.261(1); RCW 18.106.150(1)): Washington lets homeowners do their own construction work, including the licensed trades, on property they own. RCW 18.27.090(12) exempts any person working on his or her own property from contractor registration, but the exemption does not apply if you do contractor type work for the purpose of selling, demolishing, or leasing the property, and the separate owner exemption in RCW 18.27.090(11) is lost if you sell or lease improved property owned less than 12 months. For electrical work, RCW 19.28.261 lets you wire your own residence, farm, or place of business without an electrician license, unless the work is on construction of a new building intended for rent, sale, or lease, or on property offered for sale within 12 months after you obtained it. RCW 18.106.150(1) gives the same kind of exemption for plumbing work at your own residence, farm, or place of business. These exemptions waive the license, not the permit: an owner doing electrical work still buys an L&I electrical work permit and passes inspection (WAC 296-46B-901), and building and plumbing permits still come from your local building department. Confirm how King County applies this before you apply.
From the Library
What else needs a permit in King County
Every other permit type we have verified for this jurisdiction, with the rule that applies here.
| 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 | Not specified | Set by state L&I, not King County, under WAC 296-46B-906 (effective 7/1/2026): new... |
| 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 | Not specified | 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 | No separate patio line |
| Plumbing Permit | Permit required | Not specified | Issued by Public Health Seattle and King County rather than the county Permitting Division |
| Roof Replacement Permit | No permit needed | Not specified | 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... |
Pool Permit in other Washington localities
Everything above, sourced
Code references
National and state model-code sections the general guidance on this page is drawn from. They are not King County documents; the office above sets the local rules.
How this pool permit page for King County was verified. 2 official sources: kingcounty.gov, kingcounty.gov; fee schedule: official document. Last checked by Mario Bailey, not confirmed with King County Department of Local Services Permitting Division. Rules change; confirm before you build. How we verify.
Last checked: Report an error on this page
Compare Pool Permit requirements across Washington localities
Permit office
King County Department of Local Services Permitting Division
(206) 296-6600Permit portalWashington rule changes