Hawaii Building Codes

Hawaii State Building Code (HSBC) based on 2018 I-Codes with Hawaii amendments. Statewide mandatory adoption enforced at county level by 4 counties: City and County of Honolulu (Oahu), Hawaii County (Big Island), Maui County (Maui/Molokai/Lanai), Kauai County (Kauai/Niihau). Honolulu has extensive local amendments (ROH). Climate Zone 1 (Very Hot-Humid) statewide. SHGC 0.25 critical glazing metric. Hurricane-prone region statewide (105-130 mph basic wind speed). Wind-borne debris region. SDC D statewide (higher on Big Island due to volcanism). Active volcanic hazard zones 1-9 (Big Island). Tsunami evacuation zones (all coastal areas). Special Management Area (SMA) coastal permits (HRS 205A). Severe Formosan subterranean termite zone - mandatory soil treatment. Salt air corrosion - stainless steel/galvanized fasteners required within 300 ft of saltwater. No statewide GC license (county-level licensing). UPC (not IPC) for plumbing. 4 counties, no incorporated cities.; Updated 2026-03: Corrected to IRC 2018 (HSBC-R 2018 is current per applicableCodes); Identity: legal=HSBC-R 2018 (Hawaii State Building Code - Residential), basis=IRC 2018 (content served from basis). See task #527.