Accessory Structures in Maui County, HI (2026)
4 rules for unincorporated Maui County, Hawaii.
Verified from official government sources
ADU Rules
Maui County scales an accessory dwelling's maximum floor area to lot size, from 500 square feet on small lots up to 1,200 square feet on lots over two acres, and caps how many can go on one lot depending on the island.
Maui County Accessory Dwelling Size & Count Rules
Some RestrictionsMaui County Code §§ 19.35.020, 19.35.050
Lot Area (in square feet) Maximum Gross Covered Floor Area (in square feet) Up to 7,499 500 7,500 to 9,999 600 10,000 to 21,779 720 21,780 to 43,559 840 43,560 to 87,119 960 87,120 or more 1,200 ... A.Maui:1.No more than one accessory dwelling shall be permitted on any lot that is less than 7,500 square feet.2.No more than two accessory dwellings shall be permitted on any lot that is 7,500 squ...
ADU Impact Fees
An accessory dwelling on Maui pays only half the water system development fee that a standalone home owes. Maui County Code section 14.07.080(A) sets the accessory dwelling building permit fee at one-half of the full water system development fee for the meter size required, and section 14.07.070 applies the same half-rate to a new meter added later for an existing accessory dwelling.
Maui County ADU Water System Development Fee
Some RestrictionsMaui County Code §§ 14.07.070, 14.07.080(A)
Additional meter(s) for existing accessory dwellings may be requested at premises presently provided water service and, if granted, shall be subject to one half of the water system development fee set forth in the annual budget. ... A.Any applicant for a building permit for an accessory dwelling will pay one-half of the water system development fee for the size meter required to be installed. I...
ADU Rental Restrictions
Maui County flatly bars any accessory dwelling from operating as a bed and breakfast home, short-term rental home, or transient vacation rental, closing off the ohana unit as a workaround for county's separately licensed vacation-rental categories.
Maui County Bans Short-Term Rentals in ADUs
Heavy RestrictionsMaui County Code § 19.35.010(D)
D.No accessory dwelling shall be used as a bed and breakfast home, short-term rental home, or transient vacation rental.
Shed & Carport Rules
Maui County's building code exempts small detached accessory structures like sheds from needing a building permit, but only within strict limits: one story, no more than 120 square feet of gross floor area, not used as living space or for storing a vehicle or hazardous materials, and clear of any required exit path.
Maui County Shed Permit Threshold
Light RestrictionsMaui County Code § 16.25.105, subsection 105.2(1)
Building permits will not be required for the following: 1. One-story detached accessory structures not greater than 120 square feet in gross floor area, not used as a habitable space, storage of motor vehicles or hazardous materials, and does not block egress.
All Maui County ordinances
See every category we cover for Maui County: parking, noise, fences, fires, animals, pools, and more.
Maui County Ordinance Hub →