How much does it cost to build an ADU in Honolulu? The usual ADU & ohana unit job filed with Honolulu is $150,000, from 297 priced permits (July 2022 through June 2025); the middle half of firms file between $120,000 and $215,000. A filed value is what the contractor wrote on the permit, not a quote or the final bill.
The usual ADU & ohana unit job filed with Honolulu is $150,000, from 297 priced permits, July 2022 through June 2025. The middle half of firms usually file between $120,000 and $215,000. Half of jobs were filed for less, half for more. A filed value is what the contractor wrote on the permit, not a quote or the final bill. An ADU & ohana unit permit here usually takes 533 days from issue to final inspection. How long permits take →
Approximately, from each firm's own spread: every firm's range of filed values, weighted by its 297 priced permits across 139 firms, pooled into one. Half of Honolulu ADU & ohana unit permits were filed between $99,800 and $245,000.
| Percentile | Filed value | Reads as |
|---|---|---|
| 10th | $39,900 | 1 in 10 permits filed below |
| 25th | $99,800 | 1 in 4 filed below |
| 50th | $150,000 | the middle permit |
| 75th | $245,000 | 1 in 4 filed above |
| 90th | $380,000 | 1 in 10 filed above |
Firms split into thirds by the usual value of the homes they work on, with each third's usual filed value weighted by permits. Home values: 2022 assessed values for Honolulu parcels.
| Firms working on | Usual home value | Usual filed value | Firms | Permits |
|---|---|---|---|---|
| Lower third | under $986,000 | $160,000 | 46 | 80 |
| Middle third | $986,000–$1,247,600 | $155,000 | 46 | 127 |
| Upper third | $1,253,700 and up | $150,000 | 46 | 69 |
Top 10 by permits in the last 12 months on file (Jul 2024–Jun 2025). Usual is each firm's middle filed value; middle half is the range its middle half of jobs were filed in; both are shown for firms with 5 or more priced permits. Busy is not the same as careful: pick what you value to build a list.
| Firm | Permits | Last 12 mo | Usual | Middle half | Finished |
|---|---|---|---|---|---|
| FU Long Construction Inc | 15 | 12 | $190,000 | $117,190–$288,125 | — |
| Pro Build Hawaii Construction | 13 | 11 | $90,000 | $15,000–$150,000 | — |
| Atlas Construction Inc | 7 | 6 | $120,000 | $101,707–$140,000 | — |
| K O Builders LLC | 6 | 5 | $120,000 | $106,050–$292,500 | — |
| Rui Construction, Inc | 10 | 4 | $106,500 | $97,500–$120,000 | 4 of 6 |
| S Tanaka Construction LLC | 7 | 4 | $160,000 | $123,600–$472,775 | — |
| HH Constructions Inc | 5 | 4 | $141,800 | $80,000–$160,000 | — |
| Ozzy's Construction Inc | 5 | 4 | $205,000 | $110,000–$310,000 | — |
| WQ Construction LLC | 4 | 4 | — | — | — |
| Mokulua Woodworking Ltd | 3 | 3 | — | — | — |
Line your quote up against the file. In Honolulu, 1 in 10 ADU & ohana unit filed values sit under $39,900, the middle half between $99,800 and $245,000, and 1 in 10 over $380,000.
Honolulu files the fewest ADU & ohana unit permits in July (58 against an average month of 100) and the most in April (184). If you can choose, ask for quotes in a quiet month. We have no prices by month, so this is about crews' schedules, not a discount. When each trade is busiest in Honolulu →
Source: City & County of Honolulu building permits (DPP). The window is July 2022 through June 2025; a permit filed after that isn't here yet.
Usual is the middle permit: half were filed for less, half for more. Only permits with a filed value count; a value of $0 or none is left out.
The spread is approximate: we keep seven points of each firm's own range of filed values, not every permit, and pool them.
Nobody paid to be on this page and nobody can. How the records work in Honolulu →
ADU & Ohana Unit cost in other cities: Nashville Raleigh Denver San Diego Palo Alto Bellingham San Francisco Anaheim Marin County (unincorporated) Sacramento County (unincorporated)
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