Maui ADU Rules: Can You Build Two ʻOhana Units on Your Property?

Maui County changed its accessory-dwelling rules in July 2026. Qualifying residentially zoned lots may now have up to two accessory dwellings—often called ʻohana units—in addition to the primary residence.

That sounds simple. On an actual property, it rarely is.

The new rule increases what may be possible, but it does not guarantee that every lot can physically or legally support three homes. Setbacks, water, wastewater, parking, fire access, private covenants and zoning still matter.

If you are buying a Maui property because you hope to build one or two additional units, verify that potential before assigning value to it.

What Changed in Maui County?

Effective July 8, 2026, Maui County allows up to two accessory dwellings on qualifying residentially zoned lots. With the primary residence, this creates the potential for three residential units on one property.

The County adopted the change in response to Hawaiʻi Act 39 of 2024 and HRS §46-4.8, which directed counties to allow at least two ADUs, or a reasonable equivalent, on qualifying residentially zoned lots.

The County says the new standard applies countywide and expands eligibility to certain residentially zoned properties in project districts.

This does not mean every Maui property qualifies. Agricultural, commercial and industrial properties generally do not receive the same rights under this particular ADU rule. Rural lots may also be subject to different zoning provisions.

Does Every Residential Lot Qualify for Two ADUs?

No. “Up to two” does not mean two units are guaranteed.

A proposed ADU must comply with the development and infrastructure standards that apply to the property. Before relying on ADU potential, buyers and owners should investigate:

• County zoning and project-district requirements
• Front, side and rear setbacks
• Building height and lot-coverage limits
• Water availability and meter status
• Sewer capacity or individual wastewater requirements
• Parking rules
• Driveway and emergency-access requirements
• Fire-protection requirements
• Recorded declarations and private covenants

Private restrictions are particularly easy to overlook. County zoning may permit something that an association rule or recorded covenant restricts.

A buyer should investigate both.

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

No. Maui County states that accessory dwellings may not be used as transient vacation rentals, short-term rental homes or bed-and-breakfast operations.

ADUs are intended to provide long-term residential housing. Depending on the property and household, an ADU might serve as:

• Housing for parents or adult children
• A caregiver’s residence
• A long-term rental
• A separate workspace
• Flexible living space as family needs change

It is not a shortcut to legal vacation-rental income.

When evaluating potential income from an ADU, use realistic long-term rents and confirm the permitted use directly with Maui County.

Why the New Rule Matters to Maui Buyers

An additional legal dwelling can change the practical value of a property.

For some buyers, the ability to create long-term rental income may help offset ownership costs. For others, the value comes from multigenerational living or having space for a caregiver.

However, unverified “ADU potential” should not be priced like an approved and buildable unit.

The cost and feasibility of construction can change substantially based on:

• Topography
• Utility connections
• Wastewater requirements
• Water availability
• Site access
• Grading
• Fire-code compliance

Ask for documentation. A seller’s statement that “you can build two cottages” should be treated as a starting point for research—not as a land-use approval.

Buyers comparing properties with expansion potential may also want to review my guide to buying land or building on Maui.

What Sellers Should Do Before Marketing ADU Potential

If your Maui property may support one or two additional dwellings, accurate documentation can help buyers understand the opportunity.

Start by gathering:

• The property’s zoning record
• Permits for existing structures
• A current survey, if available
• Water-meter information
• Sewer or wastewater records
• Recorded covenants and association rules
• Any existing plans or professional feasibility studies

Avoid promising that a buyer can build a specific number or size of units unless that claim is properly supported.

It is more accurate to describe a property as having “potential for additional dwellings, subject to County and other approvals” than to present an unverified concept as a certainty.

Is Financial Assistance Available?

Maui County says its Department of Housing’s ʻOhana Assistance Program may offer grants of up to $100,000 for qualifying ADU construction.

Funding, application status and eligibility requirements may change. Confirm the program’s availability directly with the Department of Housing before including assistance in a construction budget.

Purchase financing is a separate issue. Some mortgage programs have restrictions based on the property’s existing unit configuration. Buyers should ask a qualified lender to review the specific property early in the process.

ADU Due-Diligence Checklist

Before making an offer based on ADU potential:

1. Confirm the parcel’s zoning.
2. Verify that existing structures were properly permitted.
3. Review setbacks, lot coverage and height limits.
4. Confirm water availability and meter status.
5. Identify sewer service or evaluate the wastewater system.
6. Check parking, driveway and emergency access.
7. Review private covenants and association documents.
8. Obtain realistic design and construction estimates.
9. Calculate projected income using long-term rent only.
10. Do not pay an ADU premium until the important assumptions are verified.

You can explore current Maui homes for sale or view available Upcountry Maui homes to compare lot sizes, zoning and existing improvements.

Thinking About Buying or Selling a Property With ʻOhana Potential?

The most useful question is not simply whether Maui allows two ADUs. It is whether a particular property supports your plan at a cost that makes sense.

If you are comparing Maui properties—or preparing to sell one—I can help you review the available property information, evaluate comparable sales and identify the questions that should be taken to Maui County and the appropriate licensed professionals.

Call or text Benjamin Finnerty at 808-481-9748, email benjamin@the808team.com, or contact me online.

This article provides general real estate information, not legal, zoning, engineering, tax or lending advice. Regulations and program availability can change. Verify a specific property with Maui County and the appropriate licensed professionals.

Talk to Benjamin Finnerty, Your Maui REALTOR®

This guide was written by Benjamin Finnerty (S), REALTOR® (RS-83812) with The 808 Team at Keller Williams Realty Maui, based in Kīhei. Whether you’re buying, selling or planning a move to Maui, I’m happy to answer your questions—no pressure.

Call or text: 808-481-9748
Email: benjamin@the808team.com
Website: benjamin.the808team.com