With Hawaiʻi home prices among the highest in the nation, more families are turning to ADUs and ohana units to grow, stay together, and stay in Hawaiʻi — a place for grandma, a home for adult kids, or rental income to make the mortgage work. Here's what you need to know.
ADU vs. Ohana Unit — what's the difference?
Both are a second living unit on your property, but the rules differ:
- ADU (Accessory Dwelling Unit) — the modern option. Includes a full kitchen, can be rented to anyone (with a minimum lease term), and is size-capped: up to 400 sq ft on lots of 3,500–4,999 sq ft, or up to 800 sq ft on lots 5,000 sq ft and larger.
- Ohana Dwelling Unit — the older, "family" designation. Traditionally limited to family members (related by blood, marriage, adoption, etc.) and not rentable to the general public, often built with a wet bar instead of a full kitchen, and typically requiring two off-street parking spaces — but not held to the same size caps.
In short: ADU = flexible and rentable; Ohana = family-focused.
Why 2026 is a big deal — the rules just opened up.
Recent legislation made this the most ADU-friendly climate Oʻahu has ever seen:
- Ordinance 25-2 now lets many homeowners build both an ADU and an ohana unit on the same lot — "one ADU + one ohana."
- State law (Act 39) requires counties to allow at least two ADUs on residentially zoned lots by the end of 2026.
- The owner-occupancy requirement was removed under current state law — so you can rent out the main home and the ADU.
The money part — fee waivers (act while they last).
To fight the housing shortage, Honolulu has been waiving major fees for qualifying ADUs — including building permit, plan review, and wastewater system facility charges. The current waiver was extended for five years starting July 1, 2025. These waivers can save homeowners thousands of dollars — but they're an incentive program, and incentive programs eventually sunset or change. Building while the waivers are active locks in real savings.
Why build now instead of "someday":
- 💰 Fee waivers are active now — thousands in savings that may not last.
- 📈 Construction costs keep climbing — today's price beats next year's.
- 🏠 Start the benefit sooner — rental income or family space now, not years from now.
- 🏝️ Keep your family in Hawaiʻi — an ohana or ADU is how many local families afford to stay, together, on one property.
- 🔑 It adds real value to your home.
The basics for your property:
- Your lot must be residentially zoned with at least 3,500 sq ft (a firm minimum — no variance below it).
- No covenants blocking an ADU.
- An ADU needs a full kitchen, bathroom, and sleeping area.
- The process runs through Honolulu's Department of Planning & Permitting (DPP).
Rules and waivers change, and every lot is different — so the real first step is a feasibility check on your property.
Cost & timeline: most ADUs run $200,000–$400,000+ depending on size, site, and finishes, with design + permitting + construction typically spanning several months to a year or more.
How IBBUILDERS helps: we confirm what your specific lot allows under today's rules, then handle design coordination, permitting (including the fee-waiver paperwork), and the full build — one team start to finish.
Wondering if your property qualifies — and what you'd save with the current waivers? Call or text (808) 840-3193 for a free ADU feasibility consult.