ADU rules in Kailua, HI — also called accessory dwelling unit regulations or granny flat ordinances — cover setbacks, owner-occupancy, parking, and permit requirements.
Kailua homeowners may add one ADU per zoning lot in eligible residential districts, subject to city-wide density, parking, occupancy, and rental-duration restrictions set by the Honolulu Land Use Ordinance.
Under ROH Sec. 21-5.720, one accessory dwelling unit is permitted per zoning lot in Country, R-3.5, R-5, R-7.5, R-10, and R-20 districts, which cover most Kailua neighborhoods from Coconut Grove to Maunawili. The ADU must comply with minimum lot size, parking, and occupancy standards. Rentals of fewer than 30 days are prohibited, distinguishing ADUs from short-term vacation rentals heavily enforced in windward beach communities. After-the-fact permits may be pursued for structures built before September 14, 2015. Ordinance 25-2 (2025) refined advertising and rental provisions.
Unpermitted ADUs, illegal short-term rental advertising, and occupancy violations can trigger notices of violation, daily fines, and required removal.
Kailua, HI
Residential pool barriers in Kailua must meet ROH Sec. 16-6.2, which mandates fencing and other protective devices around swimming pools. These rules reduce ...
Kailua, HI
Retaining walls in Kailua follow ROH Sec. 21-4.40, which caps fill-retention walls within required yards at 6 feet. Terraced walls count toward combined heig...
Kailua, HI
Kailua fence materials are defined under ROH Sec. 21-4.60, which recognizes wrought iron, wire, wood, vinyl, plastic, and masonry with post foundations. Corr...
Kailua, HI
Fences along shared property lines in Kailua are governed by ROH Sec. 21-4.30 yard and setback rules. Honolulu has no dedicated spite-fence statute, so dispu...
Kailua, HI
Kailua public parks are closed to entry during posted night hours under ROH Sec. 10-1.2, with narrow exceptions for traversing beach parks to reach the shore...
Kailua, HI
Kailua follows the state juvenile curfew under HRS Sec. 577-16, which bars children under 16 from public places between 10:00 p.m. and 4:00 a.m. without a pa...
Side-by-side rule comparisons with other cities in Honolulu County.
See how other cities in Honolulu County handle adu rules.
See how Kailua's adu rules rules stack up against other locations.
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