Home addition cost in Montana
Statewide estimate from BLS wages and BEA prices. Reviewed Nov 4, 2026.
- Statewide range (300 sq ft)
- $38,700 – $78,400
- Per sq ft
- $128 – $255
- before permit
- Versus US midpoint
- +2%
- US $57,500
- Metros covered
- 3
Across Montana, a home addition costs about $38,700 to $78,400 for 300 sq ft. Statewide, that midpoint is 2% above the US figure of $57,500. Carpenters earn a median $28.28 an hour in Montana (US: $29.12).
Inside Montana, the metros we cover range from $57,900 (Missoula) to $60,500 (Bozeman) at the midpoint. Pick your closest city in the table for a tighter number.
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Estimated cost for 300 sq ft in Montana (statewide), standard level
$50,700 to $66,500
About $166 to $217 per sq ft before permits. Labor is about 68% of the bill.
| Part | Low | High |
|---|---|---|
| Materials | $15,000 | $19,600 |
| Labor | $34,800 | $45,500 |
| Permits and fees | $900 | $1,450 |
| Total | $50,700 | $66,500 |
Cost breakdown for 300 sq ft in Montana
| Part of the job | Low | Midpoint | High | Share |
|---|---|---|---|---|
| Materials | $11,500 | $17,300 | $23,000 | 29% |
| Labor | $26,800 | $40,100 | $53,500 | 68% |
| Permits and fees | $470 | $1,200 | $1,900 | 2% |
| Total | $38,700 | $58,600 | $78,400 | 100% |
Basic, standard or premium: Montana prices
Bands overlap on purpose, since a good standard job can cost as much as a light premium one. Below are the three bands for the default size, then a grid from bump-out (100 sq ft) to large suite (600 sq ft).
Basic
$38,700 to $54,600
Bump-out or simple room without plumbing
Standard
$50,700 to $66,500
Standard room addition with HVAC and electrical
Premium
$62,600 to $78,400
Large addition with bath or kitchen and a new foundation
| Size | Basic | Standard | Premium |
|---|---|---|---|
| bump-out (100 sq ft) | $13,200 – $18,900 | $17,500 – $23,200 | $21,700 – $27,400 |
| 20x20 room (400 sq ft) | $51,500 – $72,500 | $67,200 – $88,200 | $83,000 – $104,000 |
| large suite (600 sq ft) | $77,000 – $108,000 | $100,500 – $131,500 | $124,000 – $155,000 |
When Montana weather lets you build
Weather decides when digging and ground work can happen, and Montana is not uniform. The table uses NOAA's 1991-2020 climate normals from the weather station nearest each metro we cover, and counts the months that are neither cold nor hot enough to complicate the job.
Billings has the longest comfortable season of the metros we cover in Montana at 7 months (April through October); Missoula has the shortest at 5 (May through September). Rainfall runs from 14 inches a year in Missoula to 20 inches in Bozeman.
We do not adjust prices by month, because we have no reliable published data on seasonal pricing. Timing is still worth raising when you collect bids.
| Metro | Jan avg low °F | Jul avg high °F | Precip (in/yr) | Comfortable months |
|---|---|---|---|---|
| Billings | 18 | 87 | 14 | 7: April through October |
| Bozeman | 15 | 82 | 20 | 5: May through September |
| Missoula | 18 | 85 | 14 | 5: May through September |
Montana against its neighbors
Montana ranks 16 of 51 (the 50 states plus DC) for home addition, where 1 is the most expensive. The costliest is Hawaii at $76,300 and the cheapest Arkansas at $48,200, both for 300 sq ft at the midpoint. Montana sits at $58,600. The five states closest by workforce center are listed below.
| State | Distance | Range | Midpoint | vs. here |
|---|---|---|---|---|
| Idaho | 270 miles away | $34,700 – $70,300 | $52,500 | −10% |
| Utah | 400 miles away | $35,000 – $71,100 | $53,000 | −9% |
| Wyoming | 460 miles away | $36,100 – $73,000 | $54,600 | −7% |
| Washington | 500 miles away | $45,200 – $91,400 | $68,300 | +17% |
| Colorado | 550 miles away | $38,400 – $77,800 | $58,100 | −1% |
Related projects, priced for Montana
Each project weights the trades differently, so Montana's wage level does not push every price by the same amount. Compared with the US midpoint, bathroom remodel is +4% and kitchen remodel −2%.
| Project | Size | Range | vs. US |
|---|---|---|---|
| Kitchen remodel | 120 sq ft | $18,200 – $30,900 | −2% |
| Bathroom remodel | 45 sq ft | $4,900 – $24,200 | +4% |
| Detached garage | 576 sq ft | $28,900 – $58,000 | level |
| Roof replacement | 2,000 sq ft of roof | $6,300 – $12,700 | +2% |
What carpenters and the other trades earn in Montana
Montana's labor line is priced from 6 trades, each compared with its US median wage. After weighting by each trade's share of the work, the state comes out at 1.05 times the national level.
Carpenters (47-2031), 50% of the weighting: a median of $28.28 an hour, in line with the US median of $29.12. The middle half of them earn between $23.84 and $32.47 an hour. About 4,030 work in the state. That is 78.8 per 10,000 jobs, compared with 43.1 nationally, which suggests plenty of local crews to bid.
Cement masons and concrete finishers (47-2051), 10% of the weighting: a median of $29.63 an hour, 8% above the US median of $27.41. The middle half of them earn between $26.07 and $31.20 an hour. About 780 work in the state. That is 15.2 per 10,000 jobs, compared with 13.3 nationally, so the supply of crews looks typical.
For electricians (47-2111, weighted 10%) the local median is $36.90 an hour, which is 21% above the national $30.38. The middle half of them earn between $29.04 and $39.14 an hour. BLS counts 2,750 of them working in the state, 53.8 for every 10,000 jobs (US: 48.7), so the local bench is about average.
Plumbers, pipefitters and steamfitters (47-2152), 10% of the weighting: a median of $38.44 an hour, 25% above the US median of $30.67. The middle half of them earn between $29.32 and $45.37 an hour. About 1,860 work in the state. That is 36.4 per 10,000 jobs, compared with 30.0 nationally, which suggests plenty of local crews to bid.
For drywall and ceiling tile installers (47-2081, weighted 10%) the local median is $28.92 an hour, which is in line with the national $28.33. The middle half of them earn between $23.34 and $31.63 an hour. BLS counts 170 of them working in the state, 3.3 for every 10,000 jobs (US: 5.3), so the local bench is thinner than average.
Roofers (47-2181), 10% of the weighting: a median of $28.38 an hour, 6% above the US median of $26.65. The middle half of them earn between $23.17 and $31.09 an hour. About 370 work in the state. That is 7.2 per 10,000 jobs, compared with 8.7 nationally, so expect fewer local crews to bid.
A crew paid at the 75th percentile for carpenters ($32.47 an hour) would add about $2,750 to the statewide midpoint; one at the 25th percentile ($23.84) would take off about $2,900. Use that as a rough guide to how far a bid can sit from our midpoint on wages alone.
BLS counts 511,580 jobs across Montana (May 2025), which is 0.3% of US employment.
| Trade | Weight | 25th pct | Median | 75th pct | US median | Ratio | Level used |
|---|---|---|---|---|---|---|---|
| Carpenters (47-2031) | 50% | $23.84 | $28.28 | $32.47 | $29.12 | 0.97 | state |
| Cement masons and concrete finishers (47-2051) | 10% | $26.07 | $29.63 | $31.20 | $27.41 | 1.08 | state |
| Electricians (47-2111) | 10% | $29.04 | $36.90 | $39.14 | $30.38 | 1.21 | state |
| Plumbers, pipefitters and steamfitters (47-2152) | 10% | $29.32 | $38.44 | $45.37 | $30.67 | 1.25 | state |
| Drywall and ceiling tile installers (47-2081) | 10% | $23.34 | $28.92 | $31.63 | $28.33 | 1.02 | state |
| Roofers (47-2181) | 10% | $23.17 | $28.38 | $31.09 | $26.65 | 1.06 | state |
| Blended | 100% | 1.05 | |||||
Montana metro-by-metro prices
1 of the 3 metros sit above the statewide midpoint of $58,600, and the top-to-bottom gap is 5%. Each row prices the default size with that metro's own BLS wages and BEA price levels, so the gap between rows is real local variation rather than a flat markup.
| Metro | Range (300 sq ft) | Midpoint | vs. state |
|---|---|---|---|
| Bozeman, MT | $40,000 – $81,000 | $60,500 | +3% |
| Billings, MT | $38,700 – $78,400 | $58,600 | level |
| Missoula, MT | $38,300 – $77,500 | $57,900 | −1% |
Why two Montana quotes can differ
Type of addition
A new room is $125-$250 per sq ft; a bump-out $85-$200; an attic conversion $50-$150; a garage conversion $50-$200 (HomeGuide).
Plumbing and fixtures
Adding a bathroom or kitchen drives the price up the most.
Permits
Construction permits run $500-$2,000, or $5-$21 per $1,000 of project cost (HomeGuide).
Foundation
A foundation, framing, roofing and matching exterior finishes all have to be built before the interior work starts.
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Detailed home addition report for Montana, $9
Multi-page report for Montana: 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.
Home addition in Montana: your questions
+How much does it cost to build a home addition in Montana?
$38,700 to $78,400 for 300 sq ft, using statewide wages and prices. Metro areas inside Montana can sit above or below that.
+Which city in Montana is cheapest for home addition?
Missoula at about $57,900 (midpoint, 300 sq ft). The priciest is Bozeman at $60,500.
+Is home addition cheaper in Montana than the US average?
It is 2% more expensive: $58,600 against $57,500 for 300 sq ft at the midpoint.
+What share of the price is labor in Montana?
About 68% ($40,100). Materials are 29%. Statewide labor for this job is weighted 1.05x the national wage level.
+What do carpenters earn in Montana?
The BLS statewide median is $28.28 an hour, against $29.12 for the US. The 25th to 75th percentile range is $23.84 to $32.47.
+Where does Montana rank for home addition costs?
16th most expensive of 51 (the 50 states plus DC) at the midpoint, $58,600 for 300 sq ft. Rank 1 is the costliest.
+What do basic and premium home addition work cost in Montana?
For 300 sq ft, basic work runs $38,700 to $54,600 and premium work $62,600 to $78,400. Basic means: bump-out or simple room without plumbing. Premium means: large addition with bath or kitchen and a new foundation.
+Does the season matter for home addition in Montana?
Yes where winters or summers are hard. Of the Montana metros we cover, Billings has the most comfortable months (7 of 12) based on NOAA 1991-2020 normals. Our prices do not change by month, so ask contractors whether they charge more or less in busy and slow seasons.
Home addition by city in Montana
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 a Home Addition Cost? (2026) (accessed November 4, 2026)
- Cost to Renovate: Renovation Labor Report 2026: Where the Money Goes (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
Note on derived figures: Materials = 32% of the installed price, from Cost to Renovate's mid-range 'Structural' category split (56% labor, 32% materials, 11% permits and design). It is a category average rather than an addition-specific figure.