Home addition cost in Bellingham, WA
Local estimate from BLS wage data and BEA price levels. Reviewed Nov 4, 2026.
- Typical range (300 sq ft)
- $45,500 – $92,000
- Per sq ft
- $150 – $300
- before permit
- Versus US midpoint
- +20%
- US $57,500
- Rank of 300 metros
- #10
- 1 = most expensive
A home addition in Bellingham, WA usually costs $45,500 to $92,000 for 300 sq ft. That works out to about $150 to $300 per sq ft before permits. Compared with the national midpoint that is $11,300 more. Carpenters earn a median of $35.22 an hour in the Bellingham area, 21% above the US median of $29.12.
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Estimated cost for 300 sq ft in Bellingham, WA, standard level
$59,500 to $78,100
About $195 to $255 per sq ft before permits. Labor is about 71% of the bill.
| Part | Low | High |
|---|---|---|
| Materials | $16,400 | $21,400 |
| Labor | $42,100 | $55,000 |
| Permits and fees | $980 | $1,600 |
| Total | $59,500 | $78,100 |
Cost breakdown for 300 sq ft in Bellingham, WA
| Part of the job | Low | Midpoint | High | Share |
|---|---|---|---|---|
| Materials | $12,600 | $18,900 | $25,200 | 27% |
| Labor | $32,400 | $48,600 | $64,800 | 71% |
| Permits and fees | $520 | $1,300 | $2,050 | 2% |
| Total | $45,500 | $68,800 | $92,000 | 100% |
Why Bellingham prices look the way they do
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, Bellingham wages are 1.27 times the national level. Labor makes up about 71% of the midpoint estimate (67% at national prices).
Materials are scaled with BEA's regional price parity for goods. Bellingham is at 105.0 against 100 for the US, so a materials line of $18,000 nationally becomes $18,900 here (midpoint, 300 sq ft). Permits follow the all-items index of 103.3: $520 to $2,050.
Cost by quality level and size in Bellingham
The cited range is split into basic, standard and premium bands, then scaled to Bellingham. Bands overlap, because plenty of standard jobs cost as much as a light premium one. Sizes run from bump-out (100 sq ft) to large suite (600 sq ft).
Basic
$45,500 to $64,100
Bump-out or simple room without plumbing
Standard
$59,500 to $78,100
Standard room addition with HVAC and electrical
Premium
$73,400 to $92,000
Large addition with bath or kitchen and a new foundation
| Size | Basic | Standard | Premium |
|---|---|---|---|
| bump-out (100 sq ft) | $15,500 – $22,100 | $20,500 – $27,100 | $25,400 – $32,100 |
| 20x20 room (400 sq ft) | $60,500 – $85,100 | $79,000 – $103,500 | $97,400 – $122,000 |
| large suite (600 sq ft) | $90,500 – $127,000 | $118,000 – $154,500 | $145,500 – $182,000 |
Bellingham weather and the home addition calendar
Climate numbers on this page come from NOAA's 1991-2020 U.S. Climate Normals at the nearest suitable station, Bellingham Intl Ap (5 miles from the city center). They are 30-year averages, so any one year can run hotter, colder or wetter.
Weather is not a serious constraint for digging, grading and setting material in the ground in Bellingham: no month in the averages is cold enough (an average overnight low at or below freezing (32°F)) or hot enough (an average daytime high of 90°F or more) to rule it out, so the workable window is all year.
Bellingham gets about 35 inches of precipitation in a normal year. The wettest months are January, November and December (5.2 inches in November).
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 | 46 | 34 | 4.5 | Workable |
| Feb | 49 | 35 | 2.9 | Workable |
| Mar | 53 | 38 | 3.4 | Workable |
| Apr | 58 | 42 | 2.8 | Workable |
| May | 64 | 47 | 2.2 | Workable |
| Jun | 68 | 52 | 1.6 | Workable |
| Jul | 73 | 55 | 0.9 | Workable |
| Aug | 73 | 55 | 1.1 | Workable |
| Sep | 68 | 50 | 2.0 | Workable |
| Oct | 59 | 43 | 3.9 | Workable |
| Nov | 51 | 38 | 5.2 | Workable |
| Dec | 46 | 34 | 4.3 | Workable |
How Bellingham compares
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 $62,100 to $70,900 across Bellingham and its five closest metros.
| Area | Range | Midpoint | vs. here |
|---|---|---|---|
| Bellingham, WAthis page | $45,500 – $92,000 | $68,800 | |
| Bremerton, WA90 miles | $42,400 – $85,800 | $64,100 | −7% |
| Seattle, WA95 miles | $46,900 – $94,800 | $70,900 | +3% |
| Olympia, WA140 miles | $42,800 – $86,500 | $64,700 | −6% |
| Yakima, WA175 miles | $41,100 – $83,200 | $62,100 | −10% |
| Spokane, WA200 miles | $41,500 – $84,000 | $62,700 | −9% |
| Washington (statewide) | $45,200 – $91,400 | $68,300 | −1% |
| United States | $38,000 – $77,000 | $57,500 | −16% |
Out of the 300 metros we cover, Bellingham ranks #10 for the cost of this job (#1 is the most expensive). Statewide, Bellingham is 1% above the Washington figure.
Elsewhere in Washington
| Metro | Size | Range | Midpoint | vs. here |
|---|---|---|---|---|
| Seattle, WA | 2,086,210 jobs | $46,900 – $94,800 | $70,900 | +3% |
| Spokane, WA | 255,820 jobs | $41,500 – $84,000 | $62,700 | −9% |
| Olympia, WA | 130,300 jobs | $42,800 – $86,500 | $64,700 | −6% |
| Kennewick, WA | 129,490 jobs | $43,500 – $88,100 | $65,800 | −4% |
| Yakima, WA | 97,010 jobs | $41,100 – $83,200 | $62,100 | −10% |
| Bremerton, WA | 93,740 jobs | $42,400 – $85,800 | $64,100 | −7% |
Metros of a similar size
Big cities and small ones price differently, so here is Bellingham against the 4 metros with the closest total employment.
| Metro | Size | Range | Midpoint | vs. here |
|---|---|---|---|---|
| Bremerton, WA | 93,740 jobs | $42,400 – $85,800 | $64,100 | −7% |
| Panama City, FL | 90,610 jobs | $32,900 – $66,700 | $49,800 | −28% |
| Oshkosh, WI | 93,750 jobs | $44,700 – $90,300 | $67,500 | −2% |
| St. George, UT | 90,500 jobs | $33,200 – $67,300 | $50,200 | −27% |
What local crews earn in Bellingham
The labor line is built from BLS wage data, one trade at a time. This job draws on 6 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 Bellingham the blend is 1.27.
Carpenters (47-2031), 50% of the weighting: a median of $35.22 an hour, 21% above the US median of $29.12. The middle half of them earn between $29.17 and $46.22 an hour. About 950 work in the metro. That is 104.0 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 $37.46 an hour, 37% above the US median of $27.41. The middle half of them earn between $28.34 and $48.44 an hour. About 130 work in the metro. That is 14.2 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 $46.92 an hour, which is 54% above the national $30.38. The middle half of them earn between $33.38 and $60.08 an hour. BLS counts 560 of them working in the area, 61.3 for every 10,000 jobs (US: 48.7), so the local bench is deeper than average.
Plumbers, pipefitters and steamfitters (47-2152), 10% of the weighting: a median of $49.40 an hour, 61% above the US median of $30.67. The middle half of them earn between $30.53 and $69.49 an hour. About 540 work in the metro. That is 59.1 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 $29.80 an hour, which is 5% above the national $28.33. The middle half of them earn between $28.84 and $39.11 an hour. BLS counts 80 of them working in the area, 8.8 for every 10,000 jobs (US: 5.3), so the local bench is deeper than average.
Roofers (47-2181), 10% of the weighting: a median of $28.72 an hour, 8% above the US median of $26.65. The middle half of them earn between $24.26 and $37.17 an hour. About 440 work in the metro. That is 48.1 per 10,000 jobs, compared with 8.7 nationally, which suggests plenty of local crews to bid.
A quick sensitivity check: moving the lead trade (carpenters) from the median to the 75th percentile wage adds about $7,200 to the midpoint estimate; the 25th percentile takes off about $3,950. That is a swing of roughly 5.8% to 10.5% of the total, which is useful for judging whether a bid reflects wages or something else, such as scope or margin.
Bellingham has 91,390 jobs in total (BLS, May 2025), ranking 217th by size among the 300 metros on this site.
| Trade | Weight | 25th pct | Median | 75th pct | US median | Ratio | Level used |
|---|---|---|---|---|---|---|---|
| Carpenters (47-2031) | 50% | $29.17 | $35.22 | $46.22 | $29.12 | 1.21 | metro |
| Cement masons and concrete finishers (47-2051) | 10% | $28.34 | $37.46 | $48.44 | $27.41 | 1.37 | metro |
| Electricians (47-2111) | 10% | $33.38 | $46.92 | $60.08 | $30.38 | 1.54 | metro |
| Plumbers, pipefitters and steamfitters (47-2152) | 10% | $30.53 | $49.40 | $69.49 | $30.67 | 1.61 | metro |
| Drywall and ceiling tile installers (47-2081) | 10% | $28.84 | $29.80 | $39.11 | $28.33 | 1.05 | metro |
| Roofers (47-2181) | 10% | $24.26 | $28.72 | $37.17 | $26.65 | 1.08 | metro |
| Blended | 100% | 1.27 | |||||
Why two Bellingham quotes can differ
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.
What nearby projects cost in Bellingham
Jobs that often go together with home addition are priced below at their usual sizes, using the same Bellingham wage and price inputs. Compared with national midpoints, bathroom remodel comes out highest (+22%) and roof replacement lowest (+8%); the gap comes from the trades each job uses.
| Project | Size | Range | vs. US |
|---|---|---|---|
| Kitchen remodel | 120 sq ft | $20,400 – $34,800 | +10% |
| Bathroom remodel | 45 sq ft | $5,750 – $28,500 | +22% |
| Detached garage | 576 sq ft | $33,400 – $67,000 | +15% |
| Roof replacement | 2,000 sq ft of roof | $6,650 – $13,500 | +8% |
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 $59,500 to $78,100 for Bellingham, WA is attached.
Detailed home addition report for Bellingham, WA, $9
The report lays out the home addition numbers for Bellingham, WA 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 Bellingham: your questions
+How much does it cost to build a home addition in Bellingham?
For 300 sq ft, expect $45,500 to $92,000 in the Bellingham area. A standard-spec job lands at $59,500 to $78,100. Small jobs usually cost more per sq ft and large ones less.
+What is the price per sq ft for home addition in Bellingham?
About $150 to $300 per sq ft for materials and labor, plus $520 to $2,050 for the permit if one is needed. The US range is $125 to $250.
+Is home addition cheaper in Bellingham or Bremerton?
Bremerton is 90 miles away. The midpoint for 300 sq ft there is $64,100, which is 7% less than Bellingham ($68,800). Wage and materials indexes both feed that gap.
+How much of the bill is labor in Bellingham?
About 71% at the midpoint, or $48,600 out of $68,800. Materials are 27% and permits 2%. Nationally, labor is 67%.
+What would 20x20 room (400 sq ft) cost in Bellingham?
$60,500 to $122,000. Pick a different size in the estimator above to get your own number.
+Does home addition need a permit in Bellingham?
Often, but rules are set by your city or county building office, so call before you hire. Budget $520 to $2,050 for fees in the Bellingham area (our national range of $500 to $2,000 scaled by the local price level).
+Is Bellingham expensive for home addition compared with the rest of Washington?
Bellingham is 1% above the Washington statewide estimate ($68,300 at the midpoint). We cover 7 metros in Washington; see the state page to compare them.
+What do carpenters earn in Bellingham?
The BLS median is $35.22 an hour in the Bellingham area, compared with $29.12 nationally. The 25th to 75th percentile range is $29.17 to $46.22.
+What do basic and premium home addition work cost in Bellingham?
For 300 sq ft, basic work runs $45,500 to $64,100 and premium work $73,400 to $92,000. Basic means: bump-out or simple room without plumbing. Premium means: large addition with bath or kitchen and a new foundation.
+Is there a bad season to build a home addition in Bellingham?
Not from a temperature point of view. NOAA's 1991-2020 normals show no month with a freezing-level overnight low or a 90°F-plus average high, so timing is mostly about contractor availability and rain.
Home addition near Bellingham
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.