Accessory Structures in Kauai County, HI (2026)
5 rules for unincorporated Kauai County, Hawaii.
Verified from official government sources
ADU Rules
On Kaua'i (Kaua'i County), a residentially zoned lot with only one single-family home may add one more dwelling unit, attached or detached, as an additional dwelling unit (ADU) under Sec. 8-15.2 of the Comprehensive Zoning Ordinance. The unit must meet standard height, setback, lot coverage, parking and floor area rules before a building permit issues.
Kaua'i County Additional Dwelling Unit Rules
Some RestrictionsKaua'i County Code § 8-15.2
(a) Notwithstanding other provisions to the contrary, for any residentially zoned lot where only one (1) single-family residential dwelling is permitted, one (1) additional single-family residential dwelling unit (attached or detached) may be developed, provided: (1) All applicable County requirements, not inconsistent with Section 46-4(c), Hawai'i Revised Statutes and the County's zoning provi...
ADU Impact Fees
On Kaua'i (Kaua'i County), owners adding an Additional Rental Unit (ARU) can tap a County-funded subsidy to help pay the Facilities Reserve Charge, but taking affordable-rental credit and later dropping out triggers a sliding repayment secured by a lien on the property.
Kaua'i ARU Subsidy Offsets FRC Impact Fee
Some RestrictionsKaua'i County Code § 8-30.1(g)
Additional Rental Unit (ARU) Subsidy; Purpose. There is hereby established and created an account to be known as the "Additional Rental Unit (ARU) Subsidy" within the Housing Development Fund (Fund No. 512) for the purpose of subsidizing efforts associated with the Facilities Reserve Charge (FRC). ... Appropriation of Funds. An appropriation of $113,200 from the Housing Development Fund shall b...
ADU Rental Restrictions
Kaua'i County Code Section 22-28.2 blocks private covenants, deed restrictions and HOA bylaws from limiting or prohibiting long-term rentals, Additional Dwelling Units, Additional Rental Units and guest houses. The county protects the right to rent rather than restricting it, subject to a few grandfathered exceptions.
Kaua'i bars covenants restricting ADU rentals
Few RestrictionsKaua'i County Code Sections 22-28.1, 22-28.2
With the exception of deed restrictions approved as a condition of approval by the Planning Commission during the subdivision process, covenants, conditions, deed restrictions, declarations of condominium property regime, association bylaws, and any other agreements that run with the land shall not limit or prohibit Long-Term Rentals, Additional Dwelling Units, Additional Rental Units, and Gues...
Shed & Carport Rules
Kaua'i County exempts small accessory buildings and garden sheds under seven feet tall and 400 square feet from residential yard setbacks, while newly built sheds and similar structures in Plantation Camp wildfire zones face a stricter cap of three structures per property near the main house.
Kaua'i Shed and Accessory Structure Rules
Some RestrictionsKaua'i County Code §§ 8-4.3(b)(6), 8-8A.5(g)(1)
(6) Accessory buildings and garden or service shelters not higher than seven feet nor covering more than 400 square feet, nor exceeding 20% of the rear side property line in the longest dimension facing the rear property line, may be built without setback. ... Construction Requirements. ... For any newly proposed ... unattached accessory structures or substantial improvements to unattached acce...
Tiny Homes
On Kaua'i (Kaua'i County), Building Code Section 12-2.4 lets a homeowner build a Tiny House under the International Residential Code's Appendix Q, and defines a Tiny House as a dwelling of 500 square feet or less in floor area, not counting lofts, measured to the interior faces of the exterior walls.
Kaua'i Tiny House Building Code Definition
Light RestrictionsKaua'i County Code § 12-2.4(1)
SECTION AQ102 DEFINITIONS TINY HOUSE. A dwelling that is 500 square feet (46 m2) or less in floor area excluding lofts. The maximum total floor area of 500 square feet shall mean the sum of the horizontal areas of each floor of a building, measured from the interior faces of the exterior walls. The total floor area shall include enclosed attached accessory structures such as garages or storage ...
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