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Plumbing permit — SeaTac, Washington · Requirements sheet
Verified 2026-09-16 · Source: https://www.codepublishing.com/WA/SeaTac/#!/SeaTac13/SeaTac13170.html
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Plumbing permit in SeaTac, Washington
Permit for plumbing installations in SeaTac under the Uniform Plumbing Code as adopted at SMC 13.170.010, which also allows the International Plumbing Code as an applicant-elected alternate.
Verified 2026-09-16 · Source
When you need this permit
- SMC 13.170.010 adopts “The most current edition of the Uniform Plumbing Code as amended by the Washington State Building Code Council and published in Chapter 51-56 WAC … as now or hereafter amended”. No edition year is printed.
- YOU MAY CHOOSE A DIFFERENT PLUMBING CODE, AND THE CHOICE IS ALL OR NOTHING. SMC 13.170.010(A) lets “The most current edition of the International Plumbing Code, as published by the International Code Council” be “used as an approved alternate to the Uniform Plumbing Code per SMC 13.100.040 as an alternate material, design and method of construction.” Subsection B then closes off mixing the two: “When the approved alternate plumbing code is utilized, the entire plumbing installation shall be installed and governed under provisions of the alternate code and the permit documents shall clearly state which code is used.”
- SMC 13.170.020 is titled “Repealed.” The chapter's live content is 13.170.010.
- A plumbing permit expires one year from issuance and may be extended once by a maximum of six months under SMC 13.100.060(K)(2).
- CHECK WHO YOUR BUILDING OFFICIAL IS BEFORE YOU APPLY — ON PORT OF SEATTLE LAND IT MAY NOT BE THE CITY. SMC 13.100.010(C): “the City recognizes concurrent authority of the Port to administer, implement, and enforce the technical codes and standards adopted in this title and defers to the Port's exercise of such jurisdiction as to development projects on Port-owned property within the City which are for airport uses, as that term is defined in the February 17, 2018, interlocal agreement between the City and the Port.” The agreement is authorised by Resolution No. 17-021. The code does not reproduce the definition of “airport uses”, and that interlocal agreement was not read for this entry, so which projects fall inside the carve-out is NOT ASSERTED HERE.
- THE APPLICATION HAS ITS OWN CLOCK, SEPARATE FROM THE PERMIT'S. SMC 13.100.060(H): an application for which no permit issues within eighteen months “shall expire by limitation”; separately it expires for inactivity if the applicant “fails to respond to the Department's written request for revisions, corrections, or additional information within ninety (90) days of the date of request”. The 90-day response period can be extended on an approved schedule, but the code is explicit that doing so “shall not extend the time limitation of the application” — the two clocks do not merge. Tolling is available for a cumulative maximum of 180 days: 90 days where a land use approval must come first, or 180 where issuance waits on a related construction permit, or on both. A separate one-time 30-day extension exists only “for the purpose of paying fees, submitting required paperwork, and posting financial sureties”.
- SMC 13.100.100: appeals from the Building Official go to the Hearing Examiner, and “All references in the technical codes to the Board of Appeals shall be deemed to refer to the Hearing Examiner system of Chapter 1.20 SMC.” The section further limits the Examiner's authority over code interpretation; Chapter 1.20 SMC was not opened for this entry, so the procedure and any deadline are not asserted.
Required documents
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Fee schedule
Permit and plan review fee
SMC 13.100.070(A): “A permit or permit revision shall not be issued until all fees owed to the City of SeaTac have been paid. Show full citationHide
SMC 13.100.070(A): “A permit or permit revision shall not be issued until all fees owed to the City of SeaTac have been paid. The permit and plan review fees, together with other fees, shall be as set forth in the most recently adopted City of SeaTac Fee Schedule.” NO DOLLAR AMOUNT APPEARS IN THE CODE, and the absence is bounded: The absence is bounded to SMC 13.100.060 and 13.100.070; the Fee Schedule itself is a separate document that was not opened. WHAT THE CODE DOES PUBLISH IS THE VALUATION METHOD, which is the input the fee is computed from — 13.100.070(B): “Project valuation shall be calculated based on the then-current August Building Valuation Data Square Foot Construction Costs Table published by the International Code Council or the actual value of the work for work not included in the published table”, and “The project valuation shall be set by the Building Official.” So an applicant can reconstruct the basis of the charge without being able to read the rate.Set by City of SeaTac Fee Schedule
Investigation fee (work started without a permit)
SMC 13.100.070(C), work commencing before permit issuance: the investigation fee “shall be an amount equal to the permit fee with a minimum fee of one (1) hour at the standard hourly rate in the most… Show full citationHide
SMC 13.100.070(C), work commencing before permit issuance: the investigation fee “shall be an amount equal to the permit fee with a minimum fee of one (1) hour at the standard hourly rate in the most recent City of SeaTac Fee Schedule”, and it “shall be in addition to the required plan review and permit fees” — so starting early roughly doubles the permit cost. It reaches buildings, electrical, gas, fuel tank, mechanical, plumbing and fire suppression work, work in the right-of-way, and land clearing including grubbing. The hourly rate is not published in the code.Equal to the permit fee; 1 hour minimum
Refund of a paid permit fee
SMC 13.100.070(D) publishes the refund rule, which is unusual — most codes in this Washington set do not. Show full citationHide
SMC 13.100.070(D) publishes the refund rule, which is unusual — most codes in this Washington set do not. A full refund where the fee “was erroneously paid or collected”; “A partial refund of eighty percent (80%) if a request for refund has been received within one hundred eighty (180) days of the expiration of an application or the issuance of a permit, and for which no plan review has started or inspections have been conducted.” Permits issued on incorrect, inaccurate or incomplete information, or in violation of any ordinance, are not eligible for a refund at all.80% within 180 days if no review started
Review timeline
Plan review
Not published — contact the department
Inspection process
Tips
- THE IPC ALTERNATE IS AN ALL-OR-NOTHING ELECTION AND IT MUST BE VISIBLE IN THE PERMIT DOCUMENTS. You cannot detail part of the job to the IPC and part to the UPC — SMC 13.170.010(B) requires “the entire plumbing installation” to follow the alternate once it is chosen. Decide before drawings are issued, not at inspection.
- SeaTac is the second city in this Washington set to publish an applicant-elected plumbing alternate; Longview does too, at LMC 16.02.020. The two sit on DIFFERENT base bindings — SeaTac's plumbing adoption names no year, Longview's names 2021 — so this is two published instances of the same option, not evidence of a statewide practice.
Frequently asked questions
SeaTac requires a plumbing permit for: SMC 13.170.010 adopts “The most current edition of the Uniform Plumbing Code as amended by the Washington State Building Code Council and published in Chapter 51-56 WAC … as now or hereafter amended”. No edition year is printed.; YOU MAY CHOOSE A DIFFERENT PLUMBING CODE, AND THE CHOICE IS ALL OR NOTHING. SMC 13.170.010(A) lets “The most current edition of the International Plumbing Code, as published by the International Code Council” be “used as an approved alternate to the Uniform Plumbing Code per SMC 13.100.040 as an alternate material, design and method of construction.” Subsection B then closes off mixing the two: “When the approved alternate plumbing code is utilized, the entire plumbing installation shall be installed and governed under provisions of the alternate code and the permit documents shall clearly state which code is used.”; SMC 13.170.020 is titled “Repealed.” The chapter's live content is 13.170.010.; A plumbing permit expires one year from issuance and may be extended once by a maximum of six months under SMC 13.100.060(K)(2).; CHECK WHO YOUR BUILDING OFFICIAL IS BEFORE YOU APPLY — ON PORT OF SEATTLE LAND IT MAY NOT BE THE CITY. SMC 13.100.010(C): “the City recognizes concurrent authority of the Port to administer, implement, and enforce the technical codes and standards adopted in this title and defers to the Port's exercise of such jurisdiction as to development projects on Port-owned property within the City which are for airport uses, as that term is defined in the February 17, 2018, interlocal agreement between the City and the Port.” The agreement is authorised by Resolution No. 17-021. The code does not reproduce the definition of “airport uses”, and that interlocal agreement was not read for this entry, so which projects fall inside the carve-out is NOT ASSERTED HERE.; THE APPLICATION HAS ITS OWN CLOCK, SEPARATE FROM THE PERMIT'S. SMC 13.100.060(H): an application for which no permit issues within eighteen months “shall expire by limitation”; separately it expires for inactivity if the applicant “fails to respond to the Department's written request for revisions, corrections, or additional information within ninety (90) days of the date of request”. The 90-day response period can be extended on an approved schedule, but the code is explicit that doing so “shall not extend the time limitation of the application” — the two clocks do not merge. Tolling is available for a cumulative maximum of 180 days: 90 days where a land use approval must come first, or 180 where issuance waits on a related construction permit, or on both. A separate one-time 30-day extension exists only “for the purpose of paying fees, submitting required paperwork, and posting financial sureties”.; SMC 13.100.100: appeals from the Building Official go to the Hearing Examiner, and “All references in the technical codes to the Board of Appeals shall be deemed to refer to the Hearing Examiner system of Chapter 1.20 SMC.” The section further limits the Examiner's authority over code interpretation; Chapter 1.20 SMC was not opened for this entry, so the procedure and any deadline are not asserted.. If your project isn't listed, confirm with City of SeaTac at (206) 973-4800 before starting work.
In SeaTac, the published Permit and plan review fee is: Set by City of SeaTac Fee Schedule. Additional published fees: Investigation fee (work started without a permit) — Equal to the permit fee; 1 hour minimum; Refund of a paid permit fee — 80% within 180 days if no review started. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.
SeaTac does not publish a plan-review timeline for this permit. Contact City of SeaTac at (206) 973-4800 for current turnaround.
You'll need: Construction permit application naming the plumbing code used; Applicant's estimated project value; Permit and approved plans kept on site. See the required-documents checklist on this page for details on each.
Apply through City of SeaTac at 4800 S 188th St, SeaTac, WA 98188. Phone: (206) 973-4800. Official information: https://www.seatacwa.gov/.
SeaTac, Washington has adopted: SMC 13.110.020, opening: “The most current edition of the International Building Code, including Appendix E, as amended by the Washington State Building Code Council and published in Chapter 51-50 WAC is hereby adopted by reference as now or hereafter amended.” Subsection A adds: “Appendixes E and H are hereby adopted.”; IRC — “The most current edition of the International Residential Code” as amended by the Washington State Building Code Council and published in Chapter 51-51 WAC, with Appendices F, Q and U.; IEBC — “The most current edition”, Chapter 51-50 WAC.; IWUIC — “The most current edition”, Chapter 51-55 WAC.; IMC — SMC 13.160.010: “The most current edition of the International Mechanical Code as amended by the Washington State Building Code Council and published in Chapter 51-52 WAC is hereby adopted by reference, as now or hereafter amended.”; UPC — SMC 13.170.010: “The most current edition of the Uniform Plumbing Code”, Chapter 51-56 WAC, with the International Plumbing Code available as an applicant-elected alternate under subsection (A).; NEC — SMC 13.180.010(A): “The most current edition of the National Electrical Code (NFPA 70) approved by the Washington State Building Code Council, including Annexes A, B, and C, is hereby adopted by reference, as now or hereafter amended.”; Washington Cities Electrical Code — SMC 13.180.030, “as now in effect and as may subsequently be amended, updated, or issued as new editions”.; Chapter 19.28 RCW — SMC 13.180.020, for electricians and electrical installations, with “Department” and “Director” read as the City Department of Community and Economic Development and its Director.; NOT OPENED FOR THIS ENTRY and therefore not listed above: SMC 13.150 Fire Code, 13.200 Off-Site and On-Site Improvements, 13.210 Property Maintenance, 13.220 Energy, 13.250 Recycling Space Requirements and 13.270 Building Addresses. SMC 13.230 is shown in the Title 13 contents as Repealed.. Local amendments apply — see the SeaTac overview page for the full list.
Yes. SMC 13.170.010(A) approves the most current edition of the IPC as an alternate to the UPC under the alternate materials, design and methods provision at SMC 13.100.040. Two conditions apply under subsection (B): the entire plumbing installation must then be installed and governed under the alternate code, and the permit documents must clearly state which code is used. There is no partial election.
Sources & verification
Verified against official sources. Last reviewed 2026-09-16.
Codes & ordinances
Fees, timelines, and adopted codes are researched from each jurisdiction's published records — see how we verify. Requirements change and vary by project, so always confirm the current details with the SeaTac building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.
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