Home addition cost in Delaware
Statewide estimate from BLS wages and BEA prices. Reviewed Nov 4, 2026.
- Statewide range (300 sq ft)
- $37,100 – $75,200
- Per sq ft
- $122 – $244
- before permit
- Versus US midpoint
- −2%
- US $57,500
- Metros covered
- 1
What does it cost to build a home addition in Delaware? Plan on $37,100 to $75,200 for 300 sq ft. Wages (0.98x the US blend), materials (price index 96.2) and permit costs (99.8) put the state below the national midpoint by 2%.
Delaware has one metro in our dataset, Dover, so the statewide and metro figures are close. The state figure uses BLS statewide wages, which include rural areas.
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Estimated cost for 300 sq ft in Delaware (statewide), standard level
$48,500 to $63,800
About $159 to $207 per sq ft before permits. Labor is about 67% of the bill.
| Part | Low | High |
|---|---|---|
| Materials | $15,000 | $19,600 |
| Labor | $32,600 | $42,600 |
| Permits and fees | $950 | $1,550 |
| Total | $48,500 | $63,800 |
Cost breakdown for 300 sq ft in Delaware
| Part of the job | Low | Midpoint | High | Share |
|---|---|---|---|---|
| Materials | $11,500 | $17,300 | $23,100 | 31% |
| Labor | $25,100 | $37,600 | $50,200 | 67% |
| Permits and fees | $500 | $1,250 | $2,000 | 2% |
| Total | $37,100 | $56,200 | $75,200 | 100% |
Related projects, priced for Delaware
The table prices neighboring jobs at their usual sizes using statewide Delaware wages and prices. Against national midpoints, roof replacement comes out highest (+2%) and kitchen remodel lowest (−3%), because each job leans on different trades.
| Project | Size | Range | vs. US |
|---|---|---|---|
| Kitchen remodel | 120 sq ft | $17,900 – $30,500 | −3% |
| Bathroom remodel | 45 sq ft | $4,650 – $23,000 | −1% |
| Detached garage | 576 sq ft | $28,300 – $56,700 | −2% |
| Roof replacement | 2,000 sq ft of roof | $6,300 – $12,700 | +2% |
Delaware seasons and home addition
Season matters for home addition. For each Delaware metro below we took NOAA's 1991-2020 monthly normals from the nearest suitable station and counted comfortable months for digging and ground work.
Dover has 9 comfortable months (March through November), with about 48 inches of precipitation a year.
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 |
|---|---|---|---|---|
| Dover | 28 | 87 | 48 | 9: March through November |
Home addition: what moves the price in Delaware
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.
Which Delaware city is cheapest for home addition?
Delaware has one metro in our dataset, Dover, so the statewide and metro figures are close. The state figure uses BLS statewide wages, which include rural areas. 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 |
|---|---|---|---|
| Dover, DE | $34,700 – $70,400 | $52,600 | −6% |
Quality levels and sizes in Delaware
The cited range is cut into three overlapping bands (basic, standard and premium) and scaled to statewide Delaware wages and prices. The grid prices the same bands at 3 common sizes.
Basic
$37,100 to $52,400
Bump-out or simple room without plumbing
Standard
$48,500 to $63,800
Standard room addition with HVAC and electrical
Premium
$60,000 to $75,200
Large addition with bath or kitchen and a new foundation
| Size | Basic | Standard | Premium |
|---|---|---|---|
| bump-out (100 sq ft) | $12,700 – $18,200 | $16,800 – $22,300 | $20,900 – $26,400 |
| 20x20 room (400 sq ft) | $49,300 – $69,400 | $64,400 – $84,500 | $79,500 – $99,600 |
| large suite (600 sq ft) | $73,700 – $103,500 | $96,100 – $126,000 | $118,500 – $148,500 |
Wages behind the Delaware number
Statewide wages come from BLS's state-level estimates, which blend big cities with small towns and rural areas. 6 trades drive the labor line for this job, and the weighted ratio against the national wage level is 0.98 for Delaware.
For carpenters (47-2031, weighted 50%) the local median is $28.46 an hour, which is in line with the national $29.12. The middle half of them earn between $23.35 and $36.24 an hour. BLS counts 2,250 of them working in the state, 46.4 for every 10,000 jobs (US: 43.1), so the local bench is about average.
For cement masons and concrete finishers (47-2051, weighted 10%) the local median is $27.42 an hour, which is in line with the national $27.41. The middle half of them earn between $24.07 and $30.97 an hour. BLS counts 400 of them working in the state, 8.3 for every 10,000 jobs (US: 13.3), so the local bench is thinner than average.
Electricians (47-2111), 10% of the weighting: a median of $30.63 an hour, in line with the US median of $30.38. The middle half of them earn between $23.10 and $43.52 an hour. About 2,260 work in the state. That is 46.6 per 10,000 jobs, compared with 48.7 nationally, so the supply of crews looks typical.
For plumbers, pipefitters and steamfitters (47-2152, weighted 10%) the local median is $31.11 an hour, which is in line with the national $30.67. The middle half of them earn between $24.93 and $37.42 an hour. BLS counts 1,590 of them working in the state, 32.8 for every 10,000 jobs (US: 30.0), so the local bench is about average.
Drywall and ceiling tile installers (47-2081), 10% of the weighting: a median of $24.12 an hour, 15% below the US median of $28.33. The middle half of them earn between $18.80 and $29.46 an hour. About 350 work in the state. That is 7.2 per 10,000 jobs, compared with 5.3 nationally, which suggests plenty of local crews to bid.
For roofers (47-2181, weighted 10%) the local median is $28.58 an hour, which is 7% above the national $26.65. The middle half of them earn between $20.40 and $30.59 an hour. BLS counts 230 of them working in the state, 4.7 for every 10,000 jobs (US: 8.7), so the local bench is thinner than average.
A crew paid at the 75th percentile for carpenters ($36.24 an hour) would add about $5,100 to the statewide midpoint; one at the 25th percentile ($23.35) would take off about $3,350. Use that as a rough guide to how far a bid can sit from our midpoint on wages alone.
BLS counts 484,790 jobs across Delaware (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% | $23.35 | $28.46 | $36.24 | $29.12 | 0.98 | state |
| Cement masons and concrete finishers (47-2051) | 10% | $24.07 | $27.42 | $30.97 | $27.41 | 1.00 | state |
| Electricians (47-2111) | 10% | $23.10 | $30.63 | $43.52 | $30.38 | 1.01 | state |
| Plumbers, pipefitters and steamfitters (47-2152) | 10% | $24.93 | $31.11 | $37.42 | $30.67 | 1.01 | state |
| Drywall and ceiling tile installers (47-2081) | 10% | $18.80 | $24.12 | $29.46 | $28.33 | 0.85 | state |
| Roofers (47-2181) | 10% | $20.40 | $28.58 | $30.59 | $26.65 | 1.07 | state |
| Blended | 100% | 0.98 | |||||
Delaware versus the states around it
Delaware ranks 27 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. Delaware sits at $56,200. The five states closest by workforce center are listed below.
| State | Distance | Range | Midpoint | vs. here |
|---|---|---|---|---|
| New Jersey | 60 miles away | $42,600 – $86,300 | $64,500 | +15% |
| Maryland | 60 miles away | $39,100 – $79,300 | $59,200 | +5% |
| Pennsylvania | 100 miles away | $38,300 – $77,600 | $58,000 | +3% |
| District of Columbia | 110 miles away | $41,700 – $84,500 | $63,100 | +12% |
| New York | 150 miles away | $43,500 – $88,000 | $65,700 | +17% |
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Home addition in Delaware: your questions
+How much does it cost to build a home addition in Delaware?
$37,100 to $75,200 for 300 sq ft, using statewide wages and prices. Metro areas inside Delaware can sit above or below that.
+Which city in Delaware is cheapest for home addition?
Dover at about $52,600 (midpoint, 300 sq ft).
+Is home addition cheaper in Delaware than the US average?
It is 2% cheaper: $56,200 against $57,500 for 300 sq ft at the midpoint.
+What share of the price is labor in Delaware?
About 67% ($37,600). Materials are 31%. Statewide labor for this job is weighted 0.98x the national wage level.
+What do carpenters earn in Delaware?
The BLS statewide median is $28.46 an hour, against $29.12 for the US. The 25th to 75th percentile range is $23.35 to $36.24.
+Where does Delaware rank for home addition costs?
27th most expensive of 51 (the 50 states plus DC) at the midpoint, $56,200 for 300 sq ft. Rank 1 is the costliest.
+What do basic and premium home addition work cost in Delaware?
For 300 sq ft, basic work runs $37,100 to $52,400 and premium work $60,000 to $75,200. 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 Delaware?
Yes where winters or summers are hard. Of the Delaware metros we cover, Dover has the most comfortable months (9 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 Delaware
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.