King County, WA Building Safety: Plumbing Permits (2026)
Key Facts
- Base permit fee
- $132 + $26 per fixture
- Permit expiration
- 18 months from issuance
- Adopted code
- 2018 Uniform Plumbing Code, WAC-amended
- Enforcing agency
- Public Health – Seattle & King County
- Penalty
- Misdemeanor; fine or imprisonment per day
Summary
Unincorporated King County adopts the 2018 Uniform Plumbing Code as its plumbing code, requiring a permit for plumbing work; the base permit fee is $132 plus $26 per fixture, and permits expire 18 months after issuance.
Chapters 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 16 and 17 and Appendices A (Recommended Rules for Sizing the Water Supply System), B (Explanatory Notes on Combination Waste and Vent Systems), I (Installation Standard for PEX Tubing Systems for Hot- and Cold-Water Distribution) and M (Peak Water Demand Calculator) of the Uniform Plumbing Code, 2018 Edition, as published by or jointly with the International Association of Plumbing and Mechanical Officials and as amended in chapter 51-56 WAC and the gas piping provisions of the International Fuel Gas Code, 2018 Edition, the National Fuel Gas Code, 2018 Edition (2018 ANSI Z223.1/NFPA 54), the Liquefied Petroleum Gas Code, 2017 Edition (2017 NFPA 58) as amended in chapter 51-52 WAC and the International Residential Code, 2018 Edition, as amended in chapter 51-51 WAC, are hereby adopted and together with King County amendments, additions, exceptions and deletions adopted in this chapter are adopted as the King County Plumbing Code and may be cited as such and referred to in this chapter as "this code." This code shall have precedence over documents adopted by reference.
B. This code also may be further clarified and implemented by administrative rules adopted in accordance with K.C.C. chapter 2.98. (Ord. 19485 § 134, 2022: Ord. 17837 § 70, 2014: Ord. 17191 § 6, 2011: Ord. 15802 § 116, 2007: Ord. 10589 § 1, 1992: Ord. 9151 § 1, 1989: Ord. 8008, 1987: Ord. 6746 § 5, 1984).
Full Breakdown
King County Code chapter 16.32 adopts the 2018 Uniform Plumbing Code, with Washington WAC amendments and county-specific changes, as the King County Plumbing Code for unincorporated areas. Public Health - Seattle & King County is the authority having jurisdiction and issues permits. A base permit costs $132 plus $26 per fixture (plumbing, gas, or backflow), with a $264/hour plan review fee where plans are required. Permits expire 18 months from issuance and can be renewed once before expiration; after that a new permit and full fee are required. Seattle, Bellevue, Kent, Renton and other incorporated cities enforce their own plumbing codes, not this chapter.
Violations & Fines
Violating the plumbing code is a misdemeanor punishable by fine or imprisonment; each day a violation continues counts as a separate offense, and the county can issue a stop-work order or suspend the permit.
Frequently Asked Questions
Does King County's plumbing code apply inside Seattle?
How long is a King County plumbing permit valid?
What plumbing code edition does King County use?
Sources & Official References
Other rules in King County
Compare King County to another location·View the Washington building safety overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.