A Maui homeowner called us in April asking whether her subdivision's CC&Rs—recorded in 1987—could block an ADU she wanted to build on a 12,000-square-foot lot. The covenants said "no secondary dwellings," and her homeowners association had sent a letter threatening legal action if she applied for a permit. We told her the covenants were unenforceable under Hawaii's new ADU law, Senate Bill 3202, which took effect in 2024 and explicitly prohibits private land-sale covenants from being used to prohibit ADUs. She submitted plans in May. The county issued the permit in June. The HOA didn't respond.
That's one datapoint, but it signals how SB 3202 is reshaping Hawaii's housing supply—not just by requiring counties to allow ADUs, but by overriding decades of private restrictions that kept ohana units and detached casitas off thousands of buildable lots. The law's December 31, 2026 deadline is still five months away, but the covenant override took effect immediately, and we're already seeing permit volume tick up on Oahu, Maui, and the Big Island.
What SB 3202 actually requires
Hawaii Senate Bill 3202, signed in 2024, does two things. First, it requires all five counties—Honolulu, Maui, Hawaii (the Big Island), Kauai, and Kalawao—to adopt zoning that allows at least two ADUs on residentially zoned lots by December 31, 2026. That's not a cap; it's a floor. A county can allow three or four ADUs if it wants, but it can't allow fewer than two.
Second, the law prohibits private land-sale covenants from being used to prohibit ADUs. If your deed restrictions or subdivision CC&Rs say "no accessory dwellings," "no ohana units," or "no structures other than a single primary residence," SB 3202 voids that language—at least as applied to ADUs that comply with the county's zoning. The homeowner still needs a building permit and still has to follow setback, height, and design rules, but the HOA can't block the project based on a covenant recorded before the law took effect.
The legislation cites a housing-cost crisis as justification: over half of Hawaii households spend more than 30% of their income on housing, according to the bill's preamble (via Maxable Space). Two ADUs per lot—especially on the larger parcels common outside Honolulu—means up to three housing units where only one existed before, without changing the underlying residential zoning or requiring a rezone.
The December 31 deadline and what happens if counties miss it
Unlike Nevada's hard July 1 backstop (covered in our Nevada post), Hawaii's SB 3202 doesn't spell out an automatic enforcement mechanism if a county misses the December 31 deadline. The law says counties "shall" adopt conforming zoning by year-end, but it doesn't say ADUs become by-right statewide if a county drags its feet.
That doesn't mean the deadline is optional. Hawaii has a history of legislative mandates with delayed local compliance—the state's short-term rental crackdown in 2019 took two years for some counties to fully implement—but SB 3202 was written tightly enough that we expect all five counties to adopt by December 31. Here's where each stands as of mid-2026:
- Honolulu (Oahu): Adopted updated ADU rules in November 2025, allowing two detached or attached ADUs on any residentially zoned lot 5,000 square feet or larger. Parking is required at one space per ADU, but the county waives the requirement within a half-mile of a bus stop.
- Maui County: Published a draft ordinance in February 2026 allowing two ADUs on lots 7,500 square feet or larger. The draft passed first reading in March and is scheduled for final adoption in August, well ahead of the deadline.
- Hawaii County (Big Island): Adopted interim ADU standards in January 2026 allowing two ADUs per lot countywide, with no minimum lot size. The interim rules expire December 31, 2026, at which point permanent zoning takes effect.
- Kauai County: As of June 2026, Kauai hadn't published a draft ordinance. The county planning department told us in May that it's working on standards but hasn't set a hearing date. This is the jurisdiction most at risk of missing the deadline.
- Kalawao County: Kalawao is the state's smallest county (population under 100, covering the Kalaupapa peninsula). It has no residential zoning as of mid-2026 and may request an exemption from the Legislature.
If Kauai or another county misses December 31, the likely outcome is a lawsuit from a housing-advocacy group or a homeowner whose ADU permit was denied. Hawaii courts have a track record of enforcing "shall adopt" language in state preemption statutes, so a county that drags its feet past the deadline risks losing any ability to set local standards—even if the law doesn't include an automatic backstop.
Why the covenant override is the bigger deal for builders
The two-ADU mandate affects how many units a county must allow, but the covenant override affects how many units actually get built. Before SB 3202, an estimated 40–60% of Oahu's single-family subdivisions had deed restrictions prohibiting secondary dwellings, according to anecdotal reports from county planning staff. Those covenants were enforceable as private contracts, even if the county's zoning allowed ADUs.
Now they're not. The law says private covenants "can't be used to prohibit ADUs," which means:
- An HOA can't deny architectural approval for an ADU on the grounds that the CC&Rs ban secondary structures.
- A neighbor can't sue to block an ADU based on a covenant, even if the covenant was recorded after the primary house was built.
- A title company can't flag a covenant as a cloud on title if the homeowner discloses that they plan to add an ADU.
The override doesn't void all covenant restrictions—just the ones that prohibit ADUs outright. If your CC&Rs require HOA design review, you still need approval. If they limit building height to 18 feet and your ADU design is 22 feet, the HOA can still reject it. But the HOA can't say "no ADUs, period," even if the covenant was recorded in 1985 and the homeowner signed a disclosure at closing.
For our ADU clients in Hawaii, that's been the bigger unlock than the two-unit mandate. We've drafted plans for three Maui projects where the homeowner previously thought an ADU was impossible because of subdivision restrictions. Once SB 3202 took effect, the path cleared. Two of those projects are permitted; the third is waiting on utility connections.
What "two ADUs" looks like in practice
The two-unit minimum doesn't mean every lot will support two full-size detached ADUs. Lot coverage, setbacks, and septic capacity still apply. On a 5,000-square-foot lot in urban Honolulu with 30% maximum coverage, you might fit one 800-square-foot detached ADU and one 400-square-foot attached ADU (say, a garage conversion plus a backyard cottage). On a two-acre lot in upcountry Maui, you could build two 1,200-square-foot detached structures and still have room for the primary house, a pool, and a half-acre of lawn.
The county ordinances we've seen so far don't specify that one ADU must be attached and one detached. Honolulu's November 2025 rules allow two detached ADUs on the same lot, as long as total lot coverage stays under the zoning cap. Maui's draft ordinance (not yet final) allows two detached or two attached, but requires at least 10 feet of separation between structures if both are detached.
Parking is the binding constraint on smaller urban lots. Honolulu requires one space per ADU unless the lot is near transit, which means a 5,000-square-foot lot with a two-car garage for the primary house needs to add two more spaces for the ADUs—often impossible without demolishing the garage or paving the front yard. The county's waiver for transit proximity helps, but it doesn't apply to most of the island's residential neighborhoods.
For infill multifamily developers, the two-ADU rule creates an odd planning scenario. If you buy a single-family lot, subdivide it into three parcels (legal in some Honolulu zones), and build a primary house on each parcel, you can theoretically add six ADUs across the three parcels—nine total units on what was originally one lot. We haven't seen that strategy executed yet, but the math works under current zoning, and it's a lot cheaper than going through the condo-conversion process.
How the December 31 deadline affects permit timelines
If you're planning an ADU project in Hawaii and want to break ground in early 2027, submit plans before December 31, 2026—even if your county has already adopted conforming zoning. Here's why: county planning departments across the state are understaffed, and we expect a flood of ADU applications in the last quarter of 2026 as homeowners rush to get in before any final rule changes. Honolulu's planning department told us in April that ADU permit reviews are running 12–14 weeks, up from 8 weeks in 2025, and Maui is at 16 weeks.
Submitting before year-end doesn't guarantee faster approval, but it locks in your place in the queue. If your county hasn't adopted final ADU zoning yet (looking at you, Kauai), you're taking a risk by submitting early—your plans might not comply with standards that get adopted in November—but waiting until January 2027 means you're competing with every other homeowner who waited.
For custom-home clients building new primary residences with ADU-ready sites, the strategy is different. Design the ADU into the civil plan from the start—shared driveway, shared utilities, coordinated grading—so you can permit the ADU six months after the primary house is complete. That avoids the year-end rush and spreads the permit cost over two budget cycles.
If your Hawaii subdivision CC&Rs say "no accessory dwellings" and your county allows ADUs, the covenant is unenforceable under SB 3202. Submit your permit application. If the HOA pushes back, cite the statute. We've seen this work three times in six months.
What's next for Hawaii ADU permits
We'll track county adoption through December and update this post with final ordinance links as they're published. If you're working on an ADU project in Kauai or Hawaii County and need help navigating interim zoning or the covenant override, reach out—we've permitted ADUs under preemption statutes in California, Nevada, and now Hawaii, and the compliance path is clearer than it looks once you map the county's specific rules against the state floor.
The two-ADU mandate won't solve Hawaii's housing shortage on its own—production is still constrained by construction cost, labor availability, and utility capacity—but it removes the biggest regulatory barrier we've seen in 15 years of Hawaii work. If your lot can physically support two ADUs, the county has to let you build them. That's a big shift from where Hawaii zoning was in 2023.