With Hawaii home prices among the highest in the nation, more families are turning to ADUs and ohana units to grow, stay together, and stay in Hawaii — 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 500 sq ft on lots up to 4,999 sq ft, or up to 1,000 sq ft on lots 5,000 sq ft and larger (Honolulu Ordinance 25-2, effective September 30, 2025).
- 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 Oahu 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. These waivers can save homeowners a meaningful amount — but they're an incentive program, and incentive programs eventually sunset or change. Building while the waivers are active locks in real savings. We confirm which waivers apply to your project when we scope it.
Why build now instead of "someday":
- Fee waivers are active now — savings that may not last.
- Construction costs keep climbing — building sooner beats waiting.
- Start the benefit sooner — rental income or family space now, not years from now.
- Keep your family in Hawaii — an 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 and meet Honolulu's minimum lot-size requirement for an ADU — we confirm this for your specific property.
- 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: an ADU is a full small home — design, permitting, site work, utilities, and construction — so the investment varies widely with size, your lot's conditions, and finish level. Timelines typically span several months to a year or more across design, permitting, and build. We'll give you a real number for your specific lot in a design consultation.
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) 330-1164 for an ADU feasibility consult.