Hawaii (HI) Plumbing Code & Permit Rules
Uniform Plumbing Code (2018) · Updated 2026-05-31
Data: State plumbing boards, ICC, IAPMO, EPA Last verified: 2026-05-31
Hawaii has some of the strictest plumbing regulations in the country. A licensed plumber is required for most work, annual backflow testing is mandatory, and seismic strapping is required for water heaters. Homeowners should budget for professional plumbing services and compliance costs.
Plumbing Code
Hawaii follows the Uniform Plumbing Code (2018 edition).
Key Regulations
| Regulation | Status | Details |
|---|---|---|
| Plumbing Code | UPC (2018) | Uniform Plumbing Code |
| Homeowner DIY | Not allowed | Licensed plumber required |
| Water Heater Permit | Required | Seismic strapping required |
| Backflow Testing | Annual, required | |
| Seismic Strapping | Required | Water heater restraint |
DIY Plumbing in Hawaii
Hawaii requires a licensed plumber for most plumbing work. Licensed plumber required
While this increases costs, it ensures:
- Work meets current code requirements
- Proper permitting and inspection
- Warranty and liability protection
- Safe connections to water and sewer systems
Backflow Prevention
Hawaii requires annual backflow testing to protect the public water supply from contamination. Testing must be performed by a Certified tester.
Non-compliance penalty: Water service may be shut off if testing is not completed on schedule.
Water Conservation Requirements
Hawaii follows federal water conservation standards. Federal minimums apply
Lead Service Line Replacement
Hawaii has an active lead service line replacement program. Following EPA Lead and Copper Rule 2021
Data Sources
- Hawaii state plumbing board and licensing agency
- International Code Council (ICC)
- IAPMO
- EPA Safe Drinking Water Act
Updated as regulations change.
Need a licensed plumber in Hawaii?
Plumbing regulations vary by city. Connect with a licensed professional who knows your local code requirements.
Find a Licensed Plumber →Frequently Asked Questions
What plumbing code does Hawaii follow?
Hawaii follows the Uniform Plumbing Code (2018 edition).
Can I do my own plumbing work in Hawaii?
No, Hawaii requires a licensed plumber for most plumbing work.
Do I need a permit to replace a water heater in Hawaii?
Yes, Hawaii requires a permit for water heater replacement. A licensed plumber is required for the installation.
Is backflow testing required in Hawaii?
Yes, Hawaii requires annual backflow testing.
Does Hawaii require seismic strapping for water heaters?
Yes, Hawaii requires seismic strapping for water heaters. This typically involves two metal straps securing the water heater to the wall to prevent toppling during an earthquake.