Kauai County, HI Building Safety: Fire Sprinkler Requirements (2026)

Section R313.2, One- and Two-Family Dwellings Automatic Fire Sprinkler Systems, was amended by Kaua'i County Code Section 12-2.3(34) to state flatly that an automatic residential fire sprinkler system shall be installed in one- and two-family dwellings. Two exceptions follow. The first exempts additions or alterations to existing buildings that were never equipped with a residential sprinkler system in the first place, so retrofitting is not triggered by a remodel. The second, larger exception incorporates Hawai'i Revised Statutes Section 46-19.8: until June 30, 2027, no county may require installation or retrofitting of automatic fire sprinklers in any new or existing detached one- or two-family dwelling unit used only for residential purposes, or in nonresidential agricultural and aquacultural buildings located outside an urban area.

That state-law exception has a carve-out of its own: it does not apply to a new home that needs a variance from the access-road or firefighting water-supply requirements, so a house built on a substandard road or without adequate hydrant flow can still be required to sprinkler in exchange for that variance. In practice, this means the sprinkler mandate in R313.2 mainly reaches townhouses, duplexes and other structures outside the detached one- and two-family exemption, plus any detached home whose access or water supply falls short of code and needs a variance to build at all.