Hawaii plumbing code: which edition applies and what it requires
Hawaii uses the Uniform Plumbing Code (UPC). The current edition is 2018 UPC, effective 2020-05-19 (counties adopt within ~2 yrs), adopted by the Hawaii State Building Code Council (SBCC), DAGS; counties adopt by ordinance and enforced by the local authority having jurisdiction (AHJ).
Hawaii plumbing code at a glance
| Adopted code | Hawaii State Plumbing Code (2018 UPC), HAR Title 3 SBCC |
|---|---|
| Code family | UPC |
| Current edition | 2018 UPC |
| Effective date | 2020-05-19 (counties adopt within ~2 yrs) |
| Adopting authority | Hawaii State Building Code Council (SBCC), DAGS; counties adopt by ordinance |
| Trap seal protection | Addressed in Chapter 10 (Traps); barrier-type floor drain devices conform to ASSE 1072 (UPC Section 1007). |
| Waterless trap seal acceptance | The UPC recognizes barrier-type floor drain trap seal protection devices (ASSE 1072) as a trap seal protection method (UPC Section 1007). Whether one serves in lieu of a trap primer is an AHJ decision. Confirm with the AHJ. |
| Local amendments / enforcement | Statewide model + 4 counties adopt with local amendments |
This page summarizes how Hawaii adopts and applies its plumbing code. It is a reference for planning, not legal or code-compliance advice. Always confirm current requirements with the adopted code text and your local AHJ.
Does Hawaii use the IPC or the UPC?
Hawaii uses the UPC. Its plumbing code is based on the Uniform Plumbing Code published by IAPMO, not the International Plumbing Code.
The adopted code is the Hawaii State Plumbing Code (2018 UPC), HAR Title 3 SBCC, which uses the UPC as its base with state amendments. Hawaii is one of the states in the UPC family.
What edition of the plumbing code does Hawaii use, and when did it take effect?
Hawaii's current edition is 2018 UPC, effective 2020-05-19 (counties adopt within ~2 yrs), adopted by the Hawaii State Building Code Council (SBCC), DAGS; counties adopt by ordinance.
Codes update on a multi-year cycle, and an adopted-but-not-yet-effective edition can circulate near a changeover. Confirm which edition your project falls under by its permit date and your local jurisdiction.
How do local jurisdictions affect Hawaii's plumbing code?
Hawaii's code is the statewide baseline, but local jurisdictions enforce it and may add amendments. The local authority having jurisdiction (AHJ) resolves how it applies to a specific project.
Statewide model + 4 counties adopt with local amendments. Confirm any local amendments and the accepted trap-seal methods with your city or county building department before relying on a provision.
Does the plumbing code vary by city in Hawaii?
Yes. Key jurisdictions in Hawaii can differ, so the adopted code or edition changes from one city or county to the next.
Plumbing code is adopted county by county. Honolulu (Revised Ordinances Chapter 19), Maui (Chapter 16.20C), Hawaii County, and Kauai each adopt the state UPC base with local amendments. Confirm the edition with your county building department.
Pin down the exact jurisdiction before you specify or install, since the model code, edition, and amendments can differ between neighboring cities.
What does the plumbing code require for floor drains and trap seals?
Floor drains rely on a trap, and the code requires that trap seal to be maintained. A floor drain that receives little water can lose its seal to evaporation, which opens a path for sewer gas, odors, and pests.
To prevent that, codes recognize trap seal protection methods. The two most common are a trap seal primer (which adds water to the trap) and a barrier-type floor drain trap seal protection device (which provides a mechanical seal). The right approach depends on the drain, the space, and the AHJ.
In Hawaii, the requirement is in the traps chapter of the adopted code (UPC Section 1007). The UPC recognizes a barrier-type device conforming to ASSE 1072 as a trap seal protection method; whether one stands in for a trap primer is decided by the AHJ.
Are barrier-type (ASSE 1072) trap seals allowed under Hawaii's code?
Yes, as a recognized method. The UPC recognizes barrier-type floor drain trap seal protection devices conforming to ASSE 1072 (UPC Section 1007). Whether a barrier device serves in lieu of a trap primer is a decision for the AHJ under the UPC's trap-seal requirement.
Note that a restrictive "shall not be used in lieu of" clause some references show is an Oregon amendment, not part of the base UPC, so it does not apply here. As with any device, acceptance for a specific installation rests with the local AHJ.
Do I need a permit to add a floor-drain trap seal in Hawaii?
Usually not for the device itself, but always confirm with your local authority having jurisdiction.
A drop-in barrier-type trap seal device generally does not require a plumbing permit because it does not alter any piping, similar to changing a drain grate. On new construction or an already-permitted renovation, include it in the plumbing specifications.
In Hawaii, plumbing permits and inspections run through Hawaii State Building Code Council and the local building department, and a licensed plumber pulls permits for plumbing work. Licensing rules and reciprocity vary, so confirm them with the authority or your local jurisdiction.
Where can I read Hawaii's plumbing code?
The adopting authority and code text are linked below. Always confirm current requirements against the adopted code and your local AHJ.
Where Green Drain fits. Green Drain is a barrier-type waterless trap seal for floor drains. It is cUPC listed through IAPMO (File No. 9301) and tested to ASSE 1072-2020, the standard this code references for these devices. For a floor drain at risk of a dry trap, it is one code-recognized way to keep the trap seal intact, and it works alongside the existing P-trap rather than replacing it.
Acceptance for any specific installation rests with your local AHJ. See Green Drain certifications for listing details, or browse waterless trap seals by drain size.
Protecting floor drains in Hawaii?
Find the right waterless trap seal for your drain size, or talk to our team about a project.