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

How much does it cost to insulate a 1000 sq ft attic in Saint Peters, MO?

Blown-in attic insulation in Saint Peters, MO
$2,064
1,000 ft² of attic floor · typical range $1,086 – $3,042
Typical total$2.06 per ft² of attic floor$2,064
Range you should see in bidsthree bids on the same scope normally land inside this$1,086 – $3,042
Labor portion45% of the job — this is the part that moves by city$929
Material portion55% — bought at national prices$1,135
Insulation Workers, Floor, Ceiling, and Wall pay near Saint Petersabout $31/hr · St. Louis, MO-IL metro$65,240/yr
U.S. mean for the same tradeSOC 47-2131$54,740/yr
Versus the national pricetrade pay here runs +19.2% against the U.S. mean+$164
Climate zone 3AIECC R402.1.3 asks for R-49 in the attic at zone 3. 4,070 heating degree days and 1,939 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 Saint Peters, MO average $65,240 a year against a U.S. mean of $54,740 — a factor of 1.192 — so the labor half is scaled by that and the material half is not. Source: BLS OEWS May 2025 for the St. Louis, MO-IL metro area, SOC 47-2131.
  • Why the city matters, not just the state. Trade pay moves inside a state as much as it does between states. Crews do not commute across a state to bid a job, and materials ship at national prices either way — so a metro wage is the honest input here and a state average quietly rounds four different cities into one number.
  • Climate zone 3A. IECC R402.1.3 asks for R-49 in the attic at zone 3. 4,070 heating degree days and 1,939 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 $2,064 quote into a $2,580 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 Saint Peters, MO

$2,064 is the typical number, and three bids on the same scope normally land between $1,086 and $3,042.

That is $164 more than the same job priced at the national average.

Why the city changes the number

About 45% of this job is labor — $929 of the $2,064 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 Saint Peters average $65,240 a year, against a U.S. mean of $54,740. That is a factor of 1.192, so the labor half is scaled by it and the material half is not.

Source: BLS OEWS May 2025 for the St. Louis, MO-IL metro area, SOC 47-2131.

What the quote should include

Climate zone 3A

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 $2,064 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 $1,086 – $3,042, that is not automatically wrong — but it is the question worth asking out loud.

Nearby sizes

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