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Ikena Permit
ROH Chapter 21

R-10 Residential

A low-density residential district with a 10,000 sf minimum lot area, 35% maximum coverage, 15-ft front yard, and 10-ft rear yard. The 35% coverage limit is significantly more restrictive than the 50% standard in smaller residential zones. R-10 projects often involve pool additions and guest houses that combine to approach the coverage limit.

Common locations: Hawaii Loa Ridge, Portlock, portions of upper Kailua, and some Maunawili Valley properties.

Development standards

StandardRequirement
Minimum lot area10,000 sf
Front yard15 ft min
Rear yard10 ft min
Interior side yard5 ft min
Street-side yard10 ft min
Max lot coverage35%
Max building height30 ft
FAR limitNone

Rear yard minimum is 10 ft (doubled from R-5/R-3.5). Detached accessory structures must maintain this 10-ft rear setback unless qualifying for the reduced accessory structure exception.

Source: ROH §21-3.10-4 (R-10 district standards)

Sample calculation

Lot area12,000 sf
Max coverage (35%)4,200 sf
House + garage2,800 sf (23.3%)
Pool coping + equipment pad+180 sf
Proposed covered lanai+300 sf
New total3,280 sf (27.3%) — PASS

Common DPP plan-check violations

1Coverage exceeding 35% — pool equipment pads, covered lanais, and guest house combined
2Rear yard setback at 10 ft minimum — not the 5 ft standard architects may assume from R-5 work
3Guest house exceeding allowable floor area as percent of primary dwelling

Key exceptions and reliefs

Reduced accessory structure setbacks (3-ft rear, 3-ft side) for structures 200 sf / 15 ft or less

Development standards are based on ROH Chapter 21 as of May 2026. Verify all values against the current DPP-adopted code before relying on them. Overlay districts (SMA, flood zone, historic), special area requirements, and neighborhood-specific provisions may impose additional standards not reflected here.