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Thurston County, WA Building Safety: Plumbing Permits (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Adopted code
Uniform Plumbing Code per RCW 19.27.031
Administering department
Community Planning and Economic Development Dept.
Maximum penalty
$1,000 fine and/or 90 days imprisonment
Work without permit
Fee doubled under UPC § 103.4.3
Excluded chapters
UPC Chapters 12 and 14 not adopted

Summary

Thurston County adopts the Uniform Plumbing Code as its plumbing code under TCC § 14.28.010, administered by the Community Planning and Economic Development Department. All plumbing installations require a permit and plan review before work begins, and specific UPC chapters covering fuel-fired appliance venting and building sewers are excluded from adoption.

These county ordinances apply to unincorporated areas of Thurston County. Incorporated cities within the county may have their own rules that take precedence over county-level regulations.

A.That portion of the State Building Code known as the Uniform Plumbing Code, as defined in RCW 19.27.031, and as amended and updated by the State Building Code Council pursuant to RCW 19.27.074 and Chapter 51-56 WAC and 51-57 WAC, and as amended throughout this title, except to the extent prohibited by Chapter 19.27 RCW, is adopted as the Plumbing Code for Thurston County. Provided that Chapters 12 and 14 of this code are not adopted and that Appendices A, B, and I are adopted. Provided further that those requirements of the Uniform Plumbing Code relating to the venting and combustion air of fuel fired appliances as found in Chapter 5 and those portions of the Code addressing building sewers are not adopted. B.The Plumbing Code shall be administered in Thurston County by the Community Planning and Economic Development Department.

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 77).

Full Breakdown

074 and WAC 51-56/51-57, as the county's plumbing code. The adoption carves out specific exclusions: UPC Chapters 12 and 14 are not adopted, while Appendices A, B and I are adopted. The county also declines the UPC's venting and combustion-air requirements for fuel-fired appliances in Chapter 5, and the portions addressing building sewers, since those areas are covered elsewhere in county code. The Community Planning and Economic Development Department administers the plumbing code, and any reference to the Plumbing Code or Uniform Plumbing Code in county law means the UPC as amended by the State Building Code Council and then by the county. 17 TCC. 3. 6. 010(C).

Violations & Fines

UPC § 102.5, as amended by TCC § 14.28.020, makes plumbing code violations a misdemeanor: a fine of up to one thousand dollars, imprisonment up to ninety days, or both. Each day a violation continues counts as a separate offense. The code official may also seek injunctive relief to stop ongoing violations, independent of criminal penalties, under the same section.

Frequently Asked Questions

Does Thurston County have its own plumbing code?
No. Thurston County adopts the state-mandated Uniform Plumbing Code as defined in RCW 19.27.031 rather than writing its own, per TCC § 14.28.010. The Community Planning and Economic Development Department administers it, applying county-specific amendments only to the exact UPC sections listed; everything else stays as printed in the UPC.
Do I need a permit before starting plumbing work?
Yes. TCC § 14.28.030 requires a permit before plumbing installation, alteration or repair begins. If you start work first, UPC § 103.4.3 charges a fee equal to twice the normal building and plan review fee once the permit is issued, on top of the standard permit charges.
What happens if I violate the plumbing code?
Violating the Uniform Plumbing Code as adopted in Thurston County is a misdemeanor under UPC § 102.5, punishable by up to a $1,000 fine, up to 90 days in jail, or both, with each day of a continuing violation charged as a separate offense.
Are all Uniform Plumbing Code sections in effect in Thurston County?
No. UPC Chapters 12 and 14 were not adopted, and the UPC's venting/combustion-air rules for fuel-fired appliances in Chapter 5 and its building-sewer provisions were excluded, per § 14.28.010(A). Appendices A, B, and I were adopted; everything else in the UPC applies unless a specific county amendment says otherwise.

Sources & Official References

Other rules in Thurston County

All Thurston County rules

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