Retaining Walls: Kapolei vs Waipahu
How do retaining walls rules compare between Kapolei, HI and Waipahu, HI?
Kapolei and Waipahu have similar restriction levels.
Kapolei, HI
Honolulu County
ROH Sec. 21-4.40 limits fill-containing retaining walls in Kapolei to six feet within required yards and combines terraced wall heights for compliance measurement.
View full Kapolei rules →Waipahu, HI
Honolulu County
Waipahu retaining walls fall under ROH 21-4.40, capping fill-bearing walls in required yards at 6 feet with terraced heights combined, impacting stream-side and hillside plantation lots.
View full Waipahu rules →Key Facts Comparison
| Fact | Kapolei | Waipahu |
|---|---|---|
| - | - | |
| Yard max height | - | 6 feet |
| Terraced rule | - | Heights combined |
| Code section | - | ROH 21-4.40 |
| Drainage overlay | - | Chapter 14 |
Highlighted rows indicate differences between cities.
Kapolei FAQ
Can I stack two three-foot walls to build a six-foot terrace?
Terraced walls are measured together, so stacking does not avoid the six-foot cap in required yards under 21-4.40.
Do I need a permit for a short planter wall?
Planter or retaining walls under 30 inches are often exempt, but check ROH 18-3.1 and HOA rules before starting.
Waipahu FAQ
How tall can a Waipahu retaining wall be?
Walls with fill in a required yard cap at 6 feet under ROH 21-4.40. Terraced walls are measured as combined height. Engineering review is required above the 30-inch permit threshold for taller installations.
Do old rock walls still comply?
Many legacy plantation-era rock walls are grandfathered. However, substantial alteration, repair, or replacement triggers current ROH 21-4.40 standards and may require engineered drawings plus drainage review.
Compare other topics
See how Kapolei and Waipahu compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool