That front end comes before any plan review clock starts. This page covers the order of steps, the conversion route for existing structures, and what our permit file shows. For a whole new house, see the Honolulu new home permit guide; for what an ADU is, what is an ADU.
ADU or ohana
| ADU | Ohana dwelling | |
|---|---|---|
| What it is | A second dwelling unit with its own kitchen, bedroom and bathroom, attached or detached | A second dwelling unit similar to an ADU |
| Who may live there | Not limited by DPP's definition | Only people related by blood, marriage or adoption to the family in the first dwelling |
| Pre-check form | ADU Pre-Check Form | Ohana Pre-Check Form |
| Covenant | ADU Restrictive Covenant | Ohana Restrictive Covenant |
| Rule cited by DPP | ROH Sec. 21-8.20 | ROH Sec. 21-8.20 |
Source: DPP's Preparation for Building Permit Application page, modified 9 July 2026. The lot-size, floor-area, parking and rental rules sit in the Land Use Ordinance (ROH Chapter 21); DPP's ADU Quick Guide and FAQ, linked from the same page, summarise them. Read the current versions there rather than an older third-party summary.
The order of steps
- Pre-check form. The form collects agency approvals; the clock starts at the first approval and the form is good for 210 days.
- Restrictive covenant. The Declaration of Restrictive Covenants is recorded with the Bureau of Conveyances; DPP publishes a template.
- Sewer Capacity Analysis. DPP requires an approved SCA for new structures and changes of occupancy or use; questions go to the Wastewater Branch.
- Building permit application, with the approved pre-check and covenant.
- Construction and inspections, then the final.
If 210 days pass before step 4, the pre-check is no longer valid. So the contractor's plans should be close to final before the pre-check is filed, not drawn after it comes back.
Converting an existing structure
DPP's zoning adjustment (revised 10 November 2025) lets an owner convert a legally established accessory structure built before the ADU ordinance took effect, in a country or residential district, even if it is over the ADU floor-area limit or has no room for the required parking, when the Director finds reducing it or adding parking is not feasible.
| Item | DPP's figure |
|---|---|
| Completeness check | 10 business days |
| Decision | 45 calendar days after a complete application, or the permit is deemed approved |
| Fees | $200 non-refundable initial review, plus $400 processing (2.35% surcharge on card payments) |
| Submittals | Written statement, dimensioned plans, photos, HRS Chapter 343 compliance |
The word that matters is "legally established". A garage or studio built without permits does not qualify; it first has to be legalized, see can an unpermitted ADU be legalized.
What it means for hiring
- Ask who prepares the pre-check and covenant. Some builders handle both; others expect the owner or an architect to. Put it in the contract.
- Ask how many Honolulu ADUs the firm has finished. The 210-day window, the SCA and the long build reward a firm that has done this before. Our data says few have done many: 62.6% of the 139 firms filed only one ADU permit, and just 4 filed ten or more.
- Check the license. Hawaii contractors are licensed by the state; see the Honolulu contractor license lookup.
What Honolulu ADU permits show
| Measure | Honolulu ADU and ohana |
|---|---|
| Permits, July 2022 to June 2025 | 297 |
| Firms | 139 |
| Usual filed value | $150,000 |
| Middle half of builders' usual value (31 firms) | $120,000 to $215,000 |
| Usual days, issue to final | 533 |
| Share finished | 79.6% |
| Firms with one ADU permit | 87 (62.6%) |
| Busiest / quietest month | April (184) / July (58) |
At 533 days from issue to final, the usual Honolulu ADU takes about a year and a half to build and inspect, longer than the usual addition (567 days). The usual filed value of $150,000 is the build, not the lot; against our Honolulu single-family value figure of $1,012,000, it is a fraction of what the main house is worth.
Compare Honolulu ADU builders by permits →
Typical filed values by firm: Honolulu ADU cost and addition cost. Builders side by side: compare Honolulu ADU builders. Timing by trade: how long a Honolulu permit takes. Older permits on your lot: Honolulu building permit search.
What this does not tell you
Our Honolulu file runs July 2022 to June 2025, so it misses the most recent permits, and it covers issued building permits, not pre-check forms or covenants, so it cannot show how long the front end took. DPP's ADU Quick Guide and FAQ could not be read for this page; the lot-size and floor-area limits are in those and in ROH Chapter 21.
How we know this
The pre-check, covenant and SCA steps are from Honolulu DPP's Preparation for Building Permit Application page (modified 9 July 2026), and the conversion route from DPP's zoning adjustment handout (revised 10 November 2025), both read 23 October 2026. Permit counts and filed values are City and County of Honolulu ADU and ohana building permits, July 2022 to June 2025; firm value ranges use builders with three or more permits.
Numbers come from City & County of Honolulu building permits (DPP), data through July 1, 2025. Nobody paid to be on this page and nobody can.
Questions
- What is the difference between an ADU and an ohana unit in Honolulu?
Both are a second dwelling on the lot. DPP describes an ADU as a second unit with its own kitchen, bedroom and bathroom, attached or detached, while an ohana dwelling may only be occupied by people related by blood, marriage or adoption to the family in the main house, and is subject to its own zoning and lot-area limits.
- What do I need before applying for an ADU building permit in Honolulu?
DPP says you must first get approvals on the ADU (or ohana) pre-check form and an approved Declaration of Restrictive Covenants from the Bureau of Conveyances. The approved pre-check is valid for only 210 days after the first agency approval.
- How long does it take to build an ADU in Honolulu?
The usual Honolulu ADU or ohana permit in our file reached its final inspection 533 days after issue, and that does not count the pre-check, covenant and plan review before the permit was issued.
- How much does an ADU cost in Honolulu?
The usual Honolulu ADU or ohana permit was filed at $150,000, and the middle half of builders usually file between $120,000 and $215,000. Those are the values on the permit, before design, the sewer analysis and fees.
- Can I turn an old garage or accessory structure into an ADU in Honolulu?
Possibly, with a zoning adjustment. DPP allows a legally established accessory structure built before the ADU ordinance, in a country or residential district, to be converted even if it exceeds the ADU floor-area limit or cannot meet the parking requirement, if the Director finds reducing it or adding parking is not feasible. Fees are $200 plus $400, and DPP must decide within 45 days of a complete application.
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- ADU construction cost in 2026: what ADU permits were filed at in 12 cities
- ADU vs home addition: what the permit file shows
- How to check a contractor's license in Hawaii
- Honolulu building permit search: HNL Build, TMK lookup and old records