East Honolulu, HI Fence Regulations: Retaining Walls (2026)

Retaining walls in East Honolulu are governed by Section 21-4.40 of the Honolulu Land Use Ordinance. A retaining wall containing fill within a required yard may not exceed six feet, measured from existing or finish grade (whichever is lower) to the top of the wall along the exposed face; terraced or combined retaining walls in the required yard are measured together. A retaining wall protecting a cut below existing grade has no height limit, except that a wall that both protects a cut and contains fill is capped at a total of six feet. A safety railing may be erected on top of any retaining wall in a required yard; if it is a different material than the wall and open at intervals so it cannot retain earth, it may not exceed six feet above the retaining wall. Safety railings or fences built of the same material as the retaining wall may not exceed a combined six-foot height measured from finish grade along the exposed face, and additional fence height of a different, non-earth-retaining material may be added up to six feet measured from the finish grade of the retained material (see Figures 21-4.2(A) and (B)). Retaining walls over 30 inches require a building permit under ROH Chapter 18.