Retaining Walls: Kapolei vs Mililani Town
How do retaining walls rules compare between Kapolei, HI and Mililani Town, HI?
Kapolei and Mililani Town 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 →Mililani Town, HI
Honolulu County
Mililani Town retaining walls follow ROH Sec. 21-4.40 rules and HOA review. Fill-retaining walls in required yards cannot exceed 6 feet, and terraced walls are measured in combination.
View full Mililani Town rules →Key Facts Comparison
| Fact | Kapolei | Mililani Town |
|---|---|---|
| - | - |
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.
Mililani Town FAQ
Do planter walls count as retaining walls?
If they hold back soil, yes; decorative low planters that don't retain earth are typically not regulated under 21-4.40.
Is HOA approval needed for a 24-inch garden wall?
Usually yes. Even ROH-exempt walls typically still need HOA architectural review in Mililani before construction.
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