Home addition cost in Portland, ME
Local estimate from BLS wage data and BEA price levels. Reviewed Nov 4, 2026.
- Typical range (300 sq ft)
- $38,900 – $78,800
- Per sq ft
- $128 – $256
- before permit
- Versus US midpoint
- +2%
- US $57,500
- Rank of 300 metros
- #94
- 1 = most expensive
If you want to build a home addition in Portland, plan on $38,900 to $78,800 for 300 sq ft, all in. Per sq ft, that is $128 to $256 for materials and labor, with the permit on top. The local midpoint lands close to the national one. Carpenters earn a median of $30.91 an hour in the Portland area, 6% above the US median of $29.12.
Estimate your home addition cost
Pick a size, a quality level and where you live. Prices update as you type.
Estimated cost for 300 sq ft in Portland, ME, standard level
$50,900 to $66,900
About $166 to $218 per sq ft before permits. Labor is about 68% of the bill.
| Part | Low | High |
|---|---|---|
| Materials | $15,200 | $19,800 |
| Labor | $34,800 | $45,500 |
| Permits and fees | $970 | $1,600 |
| Total | $50,900 | $66,900 |
Cost breakdown for 300 sq ft in Portland, ME
| Part of the job | Low | Midpoint | High | Share |
|---|---|---|---|---|
| Materials | $11,700 | $17,500 | $23,300 | 30% |
| Labor | $26,700 | $40,100 | $53,500 | 68% |
| Permits and fees | $510 | $1,250 | $2,050 | 2% |
| Total | $38,900 | $58,900 | $78,800 | 100% |
What is behind the Portland number
We price the labor side from BLS wage data for 6 trades: carpenters at 50%, cement masons and concrete finishers at 10%, electricians at 10%, plumbers, pipefitters and steamfitters at 10%, drywall and ceiling tile installers at 10%, roofers at 10%. Weighted together, Portland wages are 1.05 times the national level. Labor makes up about 68% of the midpoint estimate (67% at national prices).
On the materials line, the BEA goods price index for the Portland metro is 97.2 (US = 100). The midpoint materials bill for 300 sq ft comes to $17,500, compared with $18,000 at national prices. Permit and inspection fees are scaled by the broader index (101.9) and land at $510 to $2,050.
Climate in Portland: timing your home addition job
We use NOAA's 1991-2020 climate normals for Portland Intl Jetport (5 miles from the city center). These are 30-year monthly averages, not forecasts.
April through October is the stretch where digging, grading and setting material in the ground runs into the fewest weather problems in Portland (7 of 12 months). January, February, March, November and December have an average overnight low at or below freezing (32°F).
In January, February, March, November and December the average low is at or below freezing, which means frozen ground and slower digging, compaction and sod or stone placement. NOAA counts about 144 days a year with a low at or below 32°F at this station.
Portland gets about 48 inches of precipitation in a normal year, including roughly 69 inches of snow. The wettest months are April, October and December (5.3 inches in October). Inside the workable window, July and August are the driest, at 3.4 and 3.6 inches. The station averages about 5 days a year at 90°F or above.
Does the season change the price? Probably, but we do not have a sourced seasonal price curve, so the estimator shows a year-round figure and does not adjust by month. When you collect quotes, ask whether scheduling in a slower month gets a better rate.
| Month | Avg high °F | Avg low °F | Precip (in) | For this job |
|---|---|---|---|---|
| Jan | 32 | 16 | 3.5 | Cold |
| Feb | 35 | 17 | 3.5 | Cold |
| Mar | 42 | 26 | 4.1 | Cold |
| Apr | 54 | 35 | 4.4 | Workable |
| May | 64 | 46 | 3.7 | Workable |
| Jun | 74 | 55 | 4.2 | Workable |
| Jul | 80 | 61 | 3.4 | Workable |
| Aug | 79 | 60 | 3.6 | Workable |
| Sep | 71 | 52 | 3.8 | Workable |
| Oct | 60 | 41 | 5.3 | Workable |
| Nov | 48 | 32 | 4.3 | Cold |
| Dec | 38 | 22 | 4.5 | Cold |
Specs and site conditions that change a Portland bid
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.
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).
Portland labor market for home addition
Wages are the part of this estimate that changes most from town to town. 6 trades carry the job here, and each is compared with its US median. The weighted result for Portland is 1.05 times the national level.
For carpenters (47-2031, weighted 50%) the local median is $30.91 an hour, which is 6% above the national $29.12. The middle half of them earn between $28.45 and $35.95 an hour. BLS counts 2,230 of them working in the area, 77.3 for every 10,000 jobs (US: 43.1), so the local bench is deeper than average.
For cement masons and concrete finishers (47-2051, weighted 10%) the local median is $30.01 an hour, which is 9% above the national $27.41. The middle half of them earn between $24.70 and $31.25 an hour. BLS counts 330 of them working in the area, 11.4 for every 10,000 jobs (US: 13.3), so the local bench is about average.
Electricians (47-2111), 10% of the weighting: a median of $34.45 an hour, 13% above the US median of $30.38. The middle half of them earn between $30.72 and $38.12 an hour. About 1,870 work in the metro. That is 64.8 per 10,000 jobs, compared with 48.7 nationally, which suggests plenty of local crews to bid.
For plumbers, pipefitters and steamfitters (47-2152, weighted 10%) the local median is $31.01 an hour, which is in line with the national $30.67. The middle half of them earn between $30.51 and $36.97 an hour. BLS counts 1,740 of them working in the area, 60.3 for every 10,000 jobs (US: 30.0), so the local bench is deeper than average.
Drywall and ceiling tile installers (47-2081), 10% of the weighting: a median of $28.72 an hour, in line with the US median of $28.33. The middle half of them earn between $26.59 and $31.76 an hour. About 70 work in the metro. That is 2.4 per 10,000 jobs, compared with 5.3 nationally, so expect fewer local crews to bid.
For roofers (47-2181, weighted 10%) the local median is $24.61 an hour, which is 8% below the national $26.65. The middle half of them earn between $22.84 and $29.30 an hour. BLS counts 140 of them working in the area, 4.9 for every 10,000 jobs (US: 8.7), so the local bench is thinner than average.
Quotes come from real crews, not medians. If the carpenters on your job are paid at the 75th percentile ($35.95 an hour) instead of the median, the labor line grows by about $3,300. At the 25th percentile ($28.45) it shrinks by about $1,600. The total moves by 5.6% or 2.7%, so wages alone rarely explain a quote that is far outside our range.
For context on the local economy, BLS counts 288,480 jobs in the Portland-South Portland area. That makes it the 89th largest of the 300 metros we cover, with 0.19% of US employment.
| Trade | Weight | 25th pct | Median | 75th pct | US median | Ratio | Level used |
|---|---|---|---|---|---|---|---|
| Carpenters (47-2031) | 50% | $28.45 | $30.91 | $35.95 | $29.12 | 1.06 | metro |
| Cement masons and concrete finishers (47-2051) | 10% | $24.70 | $30.01 | $31.25 | $27.41 | 1.09 | metro |
| Electricians (47-2111) | 10% | $30.72 | $34.45 | $38.12 | $30.38 | 1.13 | metro |
| Plumbers, pipefitters and steamfitters (47-2152) | 10% | $30.51 | $31.01 | $36.97 | $30.67 | 1.01 | metro |
| Drywall and ceiling tile installers (47-2081) | 10% | $26.59 | $28.72 | $31.76 | $28.33 | 1.01 | metro |
| Roofers (47-2181) | 10% | $22.84 | $24.61 | $29.30 | $26.65 | 0.92 | metro |
| Blended | 100% | 1.05 | |||||
Is Portland cheap or dear? The local comparison
Contractors rarely work more than an hour or two from home, so the neighboring metros set a rough ceiling and floor for your quotes. Midpoints for 300 sq ft range from $58,100 to $68,100 across Portland and its five closest metros.
| Area | Range | Midpoint | vs. here |
|---|---|---|---|
| Portland, MEthis page | $38,900 – $78,800 | $58,900 | |
| Manchester, NH85 miles | $38,400 – $77,800 | $58,100 | −1% |
| Boston, MA85 miles | $44,300 – $89,700 | $67,000 | +14% |
| Worcester, MA120 miles | $45,000 – $91,100 | $68,100 | +16% |
| Barnstable, MA135 miles | $42,400 – $85,800 | $64,100 | +9% |
| Providence, RI140 miles | $39,300 – $79,700 | $59,500 | +1% |
| Maine (statewide) | $38,200 – $77,400 | $57,800 | −2% |
| United States | $38,000 – $77,000 | $57,500 | −2% |
Across 300 US metros, Portland comes in at #94 from the top. The priciest is Honolulu, HI at $79,600; the cheapest is Brownsville, TX at $44,300 (midpoints, 300 sq ft). Statewide, Portland is 2% above the Maine figure.
Other Maine metros
| Metro | Size | Range | Midpoint | vs. here |
|---|---|---|---|---|
| Bangor, ME | 72,270 jobs | $35,900 – $72,900 | $54,400 | −8% |
Cities with a workforce like Portland's
Big cities and small ones price differently, so here is Portland against the 4 metros with the closest total employment.
| Metro | Size | Range | Midpoint | vs. here |
|---|---|---|---|---|
| Stockton, CA | 289,660 jobs | $41,900 – $84,800 | $63,300 | +8% |
| Lexington, KY | 286,910 jobs | $34,300 – $69,500 | $51,900 | −12% |
| Toledo, OH | 291,530 jobs | $38,400 – $77,700 | $58,100 | −1% |
| New Haven, CT | 281,410 jobs | $40,500 – $82,000 | $61,300 | +4% |
Pick a size, pick a tier: home addition pricing in Portland
Three bands are cut from the same cited range and localized for Portland wages and prices. They overlap on purpose: a good standard job and a modest premium job can cost the same. The grid below prices the same bands at 3 common sizes.
Basic
$38,900 to $54,900
Bump-out or simple room without plumbing
Standard
$50,900 to $66,900
Standard room addition with HVAC and electrical
Premium
$62,900 to $78,800
Large addition with bath or kitchen and a new foundation
| Size | Basic | Standard | Premium |
|---|---|---|---|
| bump-out (100 sq ft) | $13,300 – $19,000 | $17,600 – $23,300 | $21,900 – $27,600 |
| 20x20 room (400 sq ft) | $51,700 – $72,800 | $67,500 – $88,600 | $83,300 – $104,500 |
| large suite (600 sq ft) | $77,300 – $108,500 | $101,000 – $132,000 | $124,500 – $155,500 |
Related projects, priced for Portland
Because every project leans on different trades, Portland's wage level does not move all prices equally. Against the US midpoint, bathroom remodel runs +5% and roof replacement −5%.
| Project | Size | Range | vs. US |
|---|---|---|---|
| Kitchen remodel | 120 sq ft | $18,400 – $31,400 | level |
| Bathroom remodel | 45 sq ft | $4,950 – $24,600 | +5% |
| Detached garage | 576 sq ft | $29,300 – $58,800 | +1% |
| Roof replacement | 2,000 sq ft of roof | $5,800 – $11,900 | −5% |
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 $50,900 to $66,900 for Portland, ME is attached.
Detailed home addition report for Portland, ME, $9
The report lays out the home addition numbers for Portland, ME line by line, with the local wage and price inputs, permit and timing notes, a quote comparison sheet and the full method. 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 Portland: your questions
+How much does it cost to build a home addition in Portland?
For 300 sq ft, expect $38,900 to $78,800 in the Portland area. A standard-spec job lands at $50,900 to $66,900. Small jobs usually cost more per sq ft and large ones less.
+What is the price per sq ft for home addition in Portland?
About $128 to $256 per sq ft for materials and labor, plus $510 to $2,050 for the permit if one is needed. The US range is $125 to $250.
+Is home addition cheaper in Portland or Manchester?
Manchester is 85 miles away. The midpoint for 300 sq ft there is $58,100, which is 1% less than Portland ($58,900). Wage and materials indexes both feed that gap.
+How much of the bill is labor in Portland?
About 68% at the midpoint, or $40,100 out of $58,900. Materials are 30% and permits 2%. Nationally, labor is 67%.
+What would 20x20 room (400 sq ft) cost in Portland?
$51,700 to $104,500. Pick a different size in the estimator above to get your own number.
+Does home addition need a permit in Portland?
Often, but rules are set by your city or county building office, so call before you hire. Budget $510 to $2,050 for fees in the Portland area (our national range of $500 to $2,000 scaled by the local price level).
+Is Portland expensive for home addition compared with the rest of Maine?
Portland is 2% above the Maine statewide estimate ($57,800 at the midpoint). We cover 2 metros in Maine; see the state page to compare them.
+What do carpenters earn in Portland?
The BLS median is $30.91 an hour in the Portland area, compared with $29.12 nationally. The 25th to 75th percentile range is $28.45 to $35.95.
+What do basic and premium home addition work cost in Portland?
For 300 sq ft, basic work runs $38,900 to $54,900 and premium work $62,900 to $78,800. Basic means: bump-out or simple room without plumbing. Premium means: large addition with bath or kitchen and a new foundation.
+When is the best time to build a home addition in Portland?
Based on NOAA 1991-2020 normals, the comfortable months for this kind of work are April through October. July and August are typically the driest of those months. Local contractors' schedules matter as much as the weather, so book early for the busy months.
Home addition near Portland
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.