BattWiseR-value targets by climate zone, and what it takes to hit them.

How much does it cost to insulate a 1600 sq ft attic in Dover, DE?

Blown-in attic insulation in Dover, DE
$3,033
1,600 ft² of attic floor · typical range $1,596 – $4,470
Typical total$1.90 per ft² of attic floor$3,033
Range you should see in bidsthree bids on the same scope normally land inside this$1,596 – $4,470
Labor portion45% of the job — this is the part that moves by city$1,365
Material portion55% — bought at national prices$1,668
Insulation Workers, Floor, Ceiling, and Wall pay near DoverBLS does not publish a metro figure for insulation workers, floor, ceiling, and wall near Dover, DE, so this is the Delaware state average, SOC 47-2131$54,460/yr
U.S. mean for the same tradeSOC 47-2131$54,740/yr
Versus the national pricetrade pay here runs −0.5% against the U.S. mean−$7
Climate zone 4AIECC R402.1.3 asks for R-49 in the attic at zone 4. 4,357 heating degree days and 1,362 cooling degree days is what that zone is standing in for—

Notes

  • Where the number comes from. The national price for blown-in attic insulation is $1.90 per ft² of attic floor — blown-in insulation pricing published for 2026, $1.00–$2.80 per ft². Labor is about 45% of that. Insulation Workers, Floor, Ceiling, and Wall near Dover, DE average $54,460 a year against a U.S. mean of $54,740 — a factor of 0.995 — so the labor half is scaled by that and the material half is not. Source: BLS does not publish a metro figure for insulation workers, floor, ceiling, and wall near Dover, DE, so this is the Delaware state average, SOC 47-2131.
  • This one falls back to a wider average. BLS did not publish a metro-level wage for this trade near Dover, DE, so the figure above is a state average. It is still the right order of magnitude, but a local bid carries more weight here than it would in a large metro where the survey has more responses.
  • Climate zone 4A. IECC R402.1.3 asks for R-49 in the attic at zone 4. 4,357 heating degree days and 1,362 cooling degree days is what that zone is standing in for.
  • What is in the price: blown fiberglass or cellulose to about R-49, baffles at the eaves, and labor.
  • What is not: removing existing insulation, air sealing before the blow, and any knob-and-tube remediation. These are the lines that turn a $3,033 quote into a $3,791 invoice, so ask about each one before signing.
  • Use this as a bid check, not a quote. It prices an average job in average condition. Difficult access, the state of what is being replaced, the season, and a crew booked out three months all move the real number, and none of them are in a per-unit average.

blown-in attic insulation in Dover, DE

$3,033 is the typical number, and three bids on the same scope normally land between $1,596 and $4,470.

That is $7 less than the same job priced at the national average.

Why the city changes the number

About 45% of this job is labor — $1,365 of the $3,033 above. Labor is the only part that moves locally; a bundle of material costs what it costs wherever it is nailed down.

Insulation Workers, Floor, Ceiling, and Wall near Dover average $54,460 a year, against a U.S. mean of $54,740. That is a factor of 0.995, so the labor half is scaled by it and the material half is not.

Source: BLS does not publish a metro figure for insulation workers, floor, ceiling, and wall near Dover, DE, so this is the Delaware state average, SOC 47-2131.

What the quote should include

Climate zone 4A

The lines that turn a quote into an invoice

Ask about each of them before you sign. On a job this size they are the difference between $3,033 and something a quarter higher.

Use it as a bid check, not a quote

This prices an average job in average condition. Access, the state of what is being replaced, the season, and a crew booked out three months all move the real number, and none of them are in a national average.

If a bid lands outside $1,596 – $4,470, that is not automatically wrong — but it is the question worth asking out loud.

Nearby sizes

Read more