By Benjamin Finnerty (S), REALTOR® (RS-83812) with Keller Williams Realty Maui · Kīhei, Maui · 808-481-9748

Quick Answer: As of July 8, 2026, Maui County allows up to two accessory dwelling units (ADUs, commonly called ʻohana units) per qualifying residential lot, on top of the main home, for three units in total. The ordinance implements Act 39, a 2023 state law. The added units are for long-term housing only: no vacation rentals, short-term rentals or bed-and-breakfasts.

I’m Benjamin Finnerty, a REALTOR® in Kīhei with Keller Williams Realty Maui, and I focus on South Maui condos, short-term-rental zoning and Maui County housing rules. Most of this year’s headlines have been about softening condo prices, the fallout from Bill 9’s short-term rental phase-out and rising insurance costs. The new ADU rules have gotten far less attention, yet for anyone buying, selling or building on a residential lot, they may be the most useful change of the year, because they change what a lot can legally hold.

What Changed With Maui’s ADU Rules in 2026?

Maui County adopted an ordinance, effective July 8, 2026, that implements Act 39, a 2023 state law requiring every Hawaii county to permit at least two ADUs on qualifying residential lots. A single-family lot that used to support one house can now, in the right zoning district, support three separate living spaces.

The county’s version standardizes the rules across Maui, Molokaʻi and Lānaʻi, and it opens eligibility to some residential properties in project districts where accessory dwellings were previously off the table entirely. Mayor Richard Bissen described the ordinance at the signing as another step toward increasing the county’s housing inventory. Three years after the Lahaina wildfire and in the middle of an ongoing housing shortage, the direction is clear: the county wants more homes on existing lots rather than more sprawl.

How Many ʻOhana Units Can You Build on a Maui Lot?

Up to two ADUs per qualifying lot, for three residential units including the main home. Here is what the county has confirmed:

• Up to two ADUs per qualifying lot, for a total of three residential units including the main home.
• Residential and rural zoning districts only. The rules don’t apply in agricultural, commercial or industrial zones.
• No vacation rentals. The added units can’t be used as transient vacation rentals, short-term rentals or bed-and-breakfasts.
• Standard development rules still apply. Each project has to meet setbacks, height limits, parking, water and wastewater capacity, and emergency access requirements, so whether a specific lot can support one or two ADUs is a parcel-by-parcel question.
• Countywide. The rules apply on Maui, Molokaʻi and Lānaʻi, and some residential properties in project districts are eligible for the first time.

Unit size limits, lot size minimums and permit timelines depend on your zoning district and your specific parcel. Confirm them with the County Department of Planning (planning@mauicounty.gov) before you budget a project.

Can a Maui ʻOhana Unit Be Used as a Vacation Rental?

No. The new ʻohana units cannot be used as vacation rentals, short-term rentals or bed-and-breakfasts. They are designed for long-term housing: a long-term rental, a caretaker’s unit, or extra space for your own household.

If the goal for a second unit is vacation-rental income, this rule isn’t the path. If the goal is long-term rental cash flow or future flexibility on your own property, it is a meaningful shift.

Is There Funding to Help Build an ADU on Maui?

Yes, potentially. The county Department of Housing’s ʻOhana Assistance Program provides up to $100,000 toward ADU construction for qualifying homeowners. Program availability and eligibility rules can change, so check current status before you count on it in a budget.

Why Do the New ADU Rules Matter for Maui Home Prices Right Now?

They arrive while prices are softer. August 2026 data from the REALTORS® Association of Maui showed the single-family median down roughly 8% year over year to around $1.2 million, and the condo median down about 13% to $564,950, even as sales volume ticked up.

For buyers, softer prices plus expanded building rights on residential lots is a combination worth a second look, especially for larger parcels in Central Maui, Upcountry or other areas zoned for the added density. For owners, a lot that can legally support three units has more potential uses, for resale and for long-term rental income, than one that can only support one. And it is a useful contrast to the condo side: while short-term rental options are narrowing there, long-term housing built through ADUs is one of the few paths the county is actively trying to make easier.

My Take: What I’m Telling Buyers and Owners About ADUs

If you’re buying, treat ADU potential as something to verify, not something to assume. Before you pay a premium for a lot because it “could” hold two more units, confirm it sits in a residential or rural zone, then check setbacks, parking, and water and wastewater capacity for that parcel. On larger Upcountry lots, water is often the deciding factor, which is why I’d read up on the Upcountry water meter waitlist before you write an offer.

If you own a residential lot and are weighing whether to sell now or wait, find out first whether your property qualifies for a second or third unit. A clear answer from the Planning Department, documented in your listing materials, gives buyers something concrete to price instead of a guess.

If you’re an investor, underwrite any ADU on long-term rents only. The vacation-rental ban on these units is explicit, and it sits alongside the condo-side changes I cover in how Bill 9 is reshaping Maui’s condo market.

This is general information, not legal or zoning advice. Please confirm your parcel with the County Department of Planning or a Hawaiʻi attorney.

Frequently Asked Questions

What is an ʻohana unit on Maui?

An ʻohana unit is the common local name for an accessory dwelling unit (ADU): a separate living space on the same lot as the main home. Since July 8, 2026, qualifying residential lots can have up to two.

Do Maui’s new ADU rules apply to agricultural land?

No. The rules apply in residential and rural zoning districts only, not in agricultural, commercial or industrial zones.

Can I rent my Maui ʻohana unit on Airbnb?

No. ADUs added under the new rules cannot be used as transient vacation rentals, short-term rentals or bed-and-breakfasts. They are intended for long-term housing.

How much does the ʻOhana Assistance Program provide?

The Department of Housing’s program provides up to $100,000 toward ADU construction for qualifying homeowners. Availability and eligibility can change, so confirm current status first.

Ask Benjamin

If you’d like help figuring out whether a specific lot qualifies, or how the new ADU rules should factor into a buying or selling decision, I’m glad to walk through it with you. I’m Benjamin Finnerty; call or text me at 808-481-9748 or email benjamin@the808team.com. I’m happy to talk it through, with no pressure.

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Sources: County of Maui (ordinance effective July 8, 2026); Maui Now and Hawaii News Now reporting (July 2026); REALTORS® Association of Maui August 2026 statistics.