Composite deck cost in Kahului, HI
Local estimate from BLS wage data and BEA price levels. Reviewed Nov 4, 2026.
- Typical range (300 sq ft)
- $15,700 – $31,400
- Per sq ft
- $52 – $104
- before permit
- Versus US midpoint
- +30%
- US $18,100
- Rank of 300 metros
- #3
- 1 = most expensive
Local price for a composite deck in the Kahului area: $15,700 to $31,400 for 300 sq ft. The low end is a basic job on easy ground; the high end is a premium spec with harder access. The midpoint runs 30% higher than the US figure. Carpenters earn a median of $39.47 an hour in the Kahului area, 36% above the US median of $29.12.
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Estimated cost for 300 sq ft in Kahului, HI, standard level
$20,400 to $26,700
About $67.50 to $88.50 per sq ft before permits. Labor is about 65% of the bill.
| Part | Low | High |
|---|---|---|
| Materials | $6,950 | $9,100 |
| Labor | $13,300 | $17,400 |
| Permits and fees | $90 | $130 |
| Total | $20,400 | $26,700 |
Cost breakdown for 300 sq ft in Kahului, HI
| Part of the job | Low | Midpoint | High | Share |
|---|---|---|---|---|
| Materials | $5,350 | $8,050 | $10,700 | 34% |
| Labor | $10,200 | $15,400 | $20,500 | 65% |
| Permits and fees | $55 | $110 | $160 | 0% |
| Total | $15,700 | $23,500 | $31,400 | 100% |
What is behind the Kahului number
Labor is 65% of the midpoint bill here, against 60% nationally. The mix of trades behind this job is carpenters (80%), construction laborers (20%). We weight each trade's local median wage by that share and compare it with the national median. In Kahului the blended ratio comes out at 1.42.
Materials are scaled with BEA's regional price parity for goods. Kahului is at 111.6 against 100 for the US, so a materials line of $7,200 nationally becomes $8,050 here (midpoint, 300 sq ft). Permits follow the all-items index of 109.4: $55 to $160.
Extras that change the Kahului total
Add-ons start from national price ranges and are scaled by 1.27 for Kahului, which is the average of the area's wage index (1.42) and goods price index (1.12). The estimator above can add them to your total.
| Add-on | Local range |
|---|---|
| Add a deck railing (approx. 0.3 ft per sq ft) | $2,300 – $6,850 |
What nearby projects cost in Kahului
Jobs that often go together with composite deck are priced below at their usual sizes, using the same Kahului wage and price inputs. Compared with national midpoints, concrete patio comes out highest (+45%) and gutters lowest (+25%); the gap comes from the trades each job uses.
| Project | Size | Range | vs. US |
|---|---|---|---|
| Wood deck | 300 sq ft | $9,450 – $18,900 | +25% |
| Concrete patio | 300 sq ft | $1,700 – $5,900 | +45% |
| Paver patio | 300 sq ft | $4,000 – $7,250 | +33% |
| Gutters | 160 linear ft | $1,650 – $5,200 | +25% |
The best months for composite deck in Kahului
Climate numbers on this page come from NOAA's 1991-2020 U.S. Climate Normals at the nearest suitable station, Kahului Ap (5 miles from the city center). They are 30-year averages, so any one year can run hotter, colder or wetter.
For exterior installation, the comfortable months in Kahului are October through July: 10 of 12. Outside them, August and September have an average daytime high of 90°F or more.
Kahului gets about 16 inches of precipitation in a normal year. The wettest months are January, March and December (2.8 inches in December). Inside the workable window, June and July are the driest, at 0.2 and 0.5 inches. The station averages about 39 days a year at 90°F or above.
We do not adjust the estimate by month, because we have no reliable published data on seasonal pricing. It is still worth asking contractors whether an off-peak start date changes their bid.
| Month | Avg high °F | Avg low °F | Precip (in) | For this job |
|---|---|---|---|---|
| Jan | 82 | 64 | 2.4 | Workable |
| Feb | 82 | 64 | 2.0 | Workable |
| Mar | 83 | 65 | 2.6 | Workable |
| Apr | 85 | 67 | 1.3 | Workable |
| May | 87 | 68 | 0.7 | Workable |
| Jun | 88 | 70 | 0.2 | Workable |
| Jul | 89 | 72 | 0.5 | Workable |
| Aug | 90 | 72 | 0.5 | Hot |
| Sep | 90 | 71 | 0.5 | Hot |
| Oct | 89 | 70 | 0.8 | Workable |
| Nov | 86 | 68 | 1.8 | Workable |
| Dec | 83 | 66 | 2.8 | Workable |
Specs and site conditions that change a Kahului bid
Board grade
Composite materials run $16-$32 per sq ft and the installed price is $40-$80 per sq ft, including the substructure (HomeGuide).
Labor
Labor for composite is $24-$48 per sq ft, higher than wood because the boards need extra parts and more careful assembly.
Drainage
Ground-level decks over poorly draining yards may need $1,000-$4,000 of drainage work first.
Who does the work: Kahului trade wages
The labor line is built from BLS wage data, one trade at a time. This job draws on 2 trades. We compare each trade's local median with the US median, weight the ratios by how much of the job each trade does, and apply the blend to the national labor cost. For Kahului the blend is 1.42.
Carpenters (47-2031), 80% of the weighting: a median of $39.47 an hour, 36% above the US median of $29.12. The middle half of them earn between $30.77 and $48.89 an hour. About 700 work in the metro. That is 94.9 per 10,000 jobs, compared with 43.1 nationally, which suggests plenty of local crews to bid.
For construction laborers (47-2061, weighted 20%) the local median is $38.35 an hour, which is 69% above the national $22.66. The middle half of them earn between $28.72 and $47.03 an hour. BLS counts 630 of them working in the area, 85.4 for every 10,000 jobs (US: 70.5), so the local bench is deeper than average.
A quick sensitivity check: moving the lead trade (carpenters) from the median to the 75th percentile wage adds about $2,800 to the midpoint estimate; the 25th percentile takes off about $2,600. That is a swing of roughly 11.0% to 11.9% of the total, which is useful for judging whether a bid reflects wages or something else, such as scope or margin.
Kahului-Wailuku has 73,750 jobs in total (BLS, May 2025), ranking 250th by size among the 300 metros on this site.
| Trade | Weight | 25th pct | Median | 75th pct | US median | Ratio | Level used |
|---|---|---|---|---|---|---|---|
| Carpenters (47-2031) | 80% | $30.77 | $39.47 | $48.89 | $29.12 | 1.36 | metro |
| Construction laborers (47-2061) | 20% | $28.72 | $38.35 | $47.03 | $22.66 | 1.69 | metro |
| Blended | 100% | 1.42 | |||||
Kahului against nearby metros and the rest of Hawaii
Same job, same size (300 sq ft), priced for the nearest metros. Honolulu is the priciest of the group at $25,200. Santa Cruz is the cheapest at $21,400.
| Area | Range | Midpoint | vs. here |
|---|---|---|---|
| Kahului, HIthis page | $15,700 – $31,400 | $23,500 | |
| Honolulu, HI110 miles | $16,800 – $33,600 | $25,200 | +7% |
| Santa Rosa, CA2340 miles | $14,600 – $29,300 | $21,900 | −7% |
| Santa Cruz, CA2350 miles | $14,300 – $28,600 | $21,400 | −9% |
| San Francisco, CA2355 miles | $16,000 – $32,000 | $24,000 | +2% |
| Napa, CA2370 miles | $14,600 – $29,200 | $21,900 | −7% |
| Hawaii (statewide) | $15,900 – $31,800 | $23,800 | +1% |
| United States | $12,100 – $24,200 | $18,100 | −23% |
Out of the 300 metros we cover, Kahului ranks #3 for the cost of this job (#1 is the most expensive). Statewide, Kahului is 1% below the Hawaii figure.
Elsewhere in Hawaii
| Metro | Size | Range | Midpoint | vs. here |
|---|---|---|---|---|
| Honolulu, HI | 446,380 jobs | $16,800 – $33,600 | $25,200 | +7% |
Metros of a similar size
Big cities and small ones price differently, so here is Kahului against the 4 metros with the closest total employment.
| Metro | Size | Range | Midpoint | vs. here |
|---|---|---|---|---|
| Rapid City, SD | 73,820 jobs | $10,600 – $21,300 | $16,000 | −32% |
| Bloomington, IN | 73,240 jobs | $11,900 – $23,800 | $17,900 | −24% |
| Blacksburg, VA | 74,070 jobs | $10,500 – $21,000 | $15,800 | −33% |
| Auburn, AL | 72,710 jobs | $10,300 – $20,600 | $15,500 | −34% |
Cost by quality level and size in Kahului
The cited range is split into basic, standard and premium bands, then scaled to Kahului. Bands overlap, because plenty of standard jobs cost as much as a light premium one. Sizes run from 10x12 (120 sq ft) to 20x20 (400 sq ft).
Basic
$15,700 to $21,900
Entry-level composite boards, low deck, simple shape
Standard
$20,400 to $26,700
Mid-grade capped boards with railing and stairs
Premium
$25,100 to $31,400
Premium capped or PVC boards, multi-level, hidden fasteners
| Size | Basic | Standard | Premium |
|---|---|---|---|
| 10x12 (120 sq ft) | $6,300 – $8,850 | $8,200 – $10,700 | $10,100 – $12,600 |
| 12x12 (144 sq ft) | $7,550 – $10,600 | $9,800 – $12,900 | $12,100 – $15,100 |
| 16x20 (320 sq ft) | $16,700 – $23,400 | $21,700 – $28,400 | $26,700 – $33,400 |
| 20x20 (400 sq ft) | $20,900 – $29,200 | $27,100 – $35,500 | $33,400 – $41,800 |
Get 3 local quotes
Tell us about the job and we will try to connect you with up to three local contractors for written quotes. It is free and you are under no obligation to hire. Your estimate of $20,400 to $26,700 for Kahului, HI is attached.
A detailed PDF report of this estimate, $9
Multi-page report for Kahului, HI: low, typical and high cost, a line-item breakdown of materials and labor by trade, permit notes, the best months to schedule, a quote comparison sheet, red flags, questions for contractors, checklists and every source. Save your estimate above, preview page 1 free, and unlock the full report for $9 one-time, or get every report with CostLocal Pro.
Composite deck in Kahului: your questions
+How much does it cost to build a composite deck in Kahului?
For 300 sq ft, expect $15,700 to $31,400 in the Kahului area. A standard-spec job lands at $20,400 to $26,700. Small jobs usually cost more per sq ft and large ones less.
+What is the price per sq ft for composite deck in Kahului?
About $52 to $104 per sq ft for materials and labor, plus $55 to $160 for the permit if one is needed. The US range is $40 to $80.
+Is composite deck cheaper in Kahului or Honolulu?
Honolulu is 110 miles away. The midpoint for 300 sq ft there is $25,200, which is 7% more than Kahului ($23,500). Wage and materials indexes both feed that gap.
+How much of the bill is labor in Kahului?
About 65% at the midpoint, or $15,400 out of $23,500. Materials are 34% and permits 0%. Nationally, labor is 60%.
+What would 16x20 (320 sq ft) cost in Kahului?
$16,700 to $33,400. Pick a different size in the estimator above to get your own number.
+Does composite deck need a permit in Kahului?
Often, but rules are set by your city or county building office, so call before you hire. Budget $55 to $160 for fees in the Kahului area (our national range of $50 to $150 scaled by the local price level).
+Is Kahului expensive for composite deck compared with the rest of Hawaii?
Kahului is 1% below the Hawaii statewide estimate ($23,800 at the midpoint). We cover 2 metros in Hawaii; see the state page to compare them.
+What do carpenters earn in Kahului?
The BLS median is $39.47 an hour in the Kahului area, compared with $29.12 nationally. The 25th to 75th percentile range is $30.77 to $48.89.
+What do basic and premium composite deck work cost in Kahului?
For 300 sq ft, basic work runs $15,700 to $21,900 and premium work $25,100 to $31,400. Basic means: entry-level composite boards, low deck, simple shape. Premium means: premium capped or PVC boards, multi-level, hidden fasteners.
+When is the best time to build a composite deck in Kahului?
Based on NOAA 1991-2020 normals, the comfortable months for this kind of work are October through July. June and July are typically the driest of those months. Local contractors' schedules matter as much as the weather, so book early for the busy months.
+What does "add a deck railing" add in Kahului?
$2,300 to $6,850 for 300 sq ft, from a national range scaled by the local wage and goods indexes.
Composite deck near Kahului
Where these numbers come from
Base prices are national ranges from the sources below. We scale labor by local BLS wages, materials by BEA goods prices and permits by the BEA all-items price level. Full method on the methodology page.
- HomeGuide: How Much Does Composite Decking Cost? (2026) (accessed November 4, 2026)
- HomeGuide: 2026 Building Permit Costs | Fees & Cost Calculator (accessed November 4, 2026)
- BLS Occupational Employment and Wage Statistics, May 2025
- BEA Regional Price Parities, 2024
- NOAA NCEI U.S. Climate Normals, 1991-2020