Retaining Walls: East Honolulu vs Kapolei
How do retaining walls rules compare between East Honolulu, HI and Kapolei, HI?
East Honolulu and Kapolei have similar restriction levels.
East Honolulu, HI
Honolulu County
East Honolulu retaining walls on Kuliouou, Hawaii Loa Ridge, and Niu Valley hillsides fall under ROH 21-4.40, which caps fill-bearing walls in required yards at 6 feet with terraced heights combined.
View full East Honolulu rules →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 →Key Facts Comparison
| Fact | East Honolulu | Kapolei |
|---|---|---|
| Yard max height | 6 feet | - |
| Terraced rule | Heights combined | - |
| Code section | ROH 21-4.40 | - |
| Engineering trigger | Above 30 inches | - |
| - | - |
Highlighted rows indicate differences between cities.
East Honolulu FAQ
How tall can a Hawaii Kai retaining wall be?
Walls containing 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 hillside lots.
Do Kuliouou hillside walls need extra review?
Yes. Steep Kuliouou and Hawaii Loa Ridge sites typically require geotechnical and drainage review, engineered drawings, and sometimes grading permits under Chapter 14 alongside the 21-4.40 retaining wall rules.
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.
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