ROH §26-1.4 (Oʻahu Shoreline Setback)
ROH §26-1.4 is the City & County of Honolulu ordinance that sets the shoreline setback on Oʻahu — the buffer, measured landward from the certified shoreline, within which building is restricted. It's the rule that determines how much of a coastal lot is actually buildable.
The setback is measured from the certified shoreline and scales with lot depth, subject to a minimum and maximum. On a shallow coastal lot the setback can consume a large share of the parcel; on a deep lot it's a smaller constraint. The certified shoreline itself can move over time, and sea-level-rise guidance is increasingly folded into coastal-setback thinking.
Because the setback is measured from the shoreline rather than the property line, two lots of the same size can have very different buildable footprints depending on their depth and orientation to the coast.
On an Oʻahu coastal parcel, the shoreline setback is often the single biggest control on buildable area — more than zoning. Estimating it from the certified shoreline and lot geometry, at today's shoreline and under sea-level-rise scenarios, is central to underwriting a coastal deal.
Under ROH §26-1.4, it's measured landward from the certified shoreline and scales with lot depth, within a minimum and maximum — not from the property line, which is why lot depth matters so much.
This is a plain-language reference, not legal advice. KILO is a pre-development screening tool, not a system of record — confirm any determination with the agency of jurisdiction.