Free Attic Insulation Calculator

Attic Insulation Cost Calculator

Get accurate cost estimates for insulating your attic based on size, insulation type, and access difficulty.

Used to determine IECC climate zone and R-value requirements

Attic floor area (typically same as home size)

Affects labor costs - difficult access adds 20-50%

Understanding Attic Insulation Costs

Attic insulation costs vary widely based on material choice, attic size, access difficulty, and regional labor rates. Here's what affects your final price:

Cost by Insulation Type

Blown Cellulose
Most affordable, eco-friendly
$1.30-1.50/sq ft
Blown Fiberglass
Popular choice, minimal settling
$1.50-2.00/sq ft
Batt Fiberglass
DIY-friendly rolls
$0.50-1.00/sq ft
Spray Foam
Premium option, air sealing + insulation
$3.00-4.00/sq ft

7 Factors That Affect Attic Insulation Cost

1Attic Size

Larger attics cost more but benefit from economies of scale. A 1,000 sq ft attic costs $1,300-2,000. A 3,000 sq ft attic costs $3,000-6,000 but the per-square-foot cost is lower.

2Current Insulation

No insulation: Full installation required. Some insulation: Can blow new material over old, saving 10-20%. Damaged insulation: Removal adds $0.50-1.00/sq ft.

3Attic Access

Easy: Pull-down stairs, 5+ ft clearance (base price). Moderate: Small hatch, 3-5 ft clearance (+20%). Difficult: Tiny opening, <3 ft clearance (+30-50%).

4Obstacles & Prep Work

Recessed lights need IC-rated covers ($10-20 each). Chimneys need metal flashing ($50-150). Roof leaks must be fixed first. Soffit vents need baffles ($2-3 each). Budget $200-500 for typical prep work.

5R-Value Target

Higher R-values require more material. Going from R-30 to R-49 adds 50% more insulation. Cold climates (R-60) cost 20-30% more than hot climates (R-30).

6Location & Labor Costs

Labor costs vary by region. Northeast and California: 15-20% higher than national average. Midwest and South: 10-15% lower. Urban areas cost more than rural.

7Air Sealing (Critical!)

Professional air sealing costs $400-800 but MUST be done before insulation. Many contractors bundle this with insulation. Without air sealing, you waste 30-40% of your insulation investment.

DIY vs Professional Installation

DIY Insulation

Cost: $500-1,500
Materials only (batt insulation)
Pros:
  • • Save 40-60% on labor
  • • Control over quality
  • • Work at your own pace
Cons:
  • • Hard physical work (hot/dirty)
  • • Takes 2-3 days
  • • Miss hidden air leaks
  • • Gaps reduce effectiveness
Best for: Small attics (<1,000 sq ft), handy homeowners, budget projects

Professional Installation

Cost: $1,300-6,000
Materials + labor (blown insulation)
Pros:
  • • Complete in 4-8 hours
  • • Better coverage (blown fills gaps)
  • • Includes air sealing inspection
  • • Warranty on workmanship
Cons:
  • • Higher upfront cost
  • • Must schedule appointment
  • • Quality varies by contractor
Best for: Large attics (>1,000 sq ft), difficult access, maximum efficiency

Recommendation: For most homeowners, professional blown insulation offers the best value. It's only 20-40% more expensive than DIY but provides 15-20% better coverage and energy savings, paying for itself within 1-2 years.

Attic Insulation Cost FAQs

What's the average cost to insulate a 2,000 sq ft attic?+

For a 2,000 sq ft attic with professional blown fiberglass insulation: $2,500-4,000. Blown cellulose: $2,200-3,500. Spray foam: $6,000-8,000. DIY batt insulation: $1,000-2,000 (materials only). Prices include air sealing prep work but vary by region and current insulation level.

How long does attic insulation installation take?+

Professional blown insulation: 4-8 hours for most attics. DIY batt installation: 2-3 full days for average homeowner. Spray foam: 1-2 days. Additional time needed for prep work (air sealing, repairing roof leaks, installing baffles). Most professional jobs completed in one day.

Do I need to remove old insulation first?+

Usually no. If old insulation is dry and in good condition, new insulation can be blown over it. However, remove old insulation if: (1) it's water-damaged or moldy, (2) infested with pests, (3) asbestos-containing (hire certified removal), or (4) compressed and ineffective. Removal costs $1.00-2.00 per sq ft.

Are there rebates or tax credits for attic insulation?+

Yes! Many utilities offer rebates of $0.15-0.30 per sq ft ($300-600 for typical attics). Federal tax credits may apply for insulation upgrades (check current IRS Energy Efficient Home Improvement Credit). Some states have additional incentives. Low-income homeowners may qualify for FREE weatherization programs. Check dsireusa.org.

Is spray foam worth the extra cost?+

Only in specific situations: (1) Low-clearance attics where you need maximum R-value per inch, (2) When you want air sealing + insulation in one step, (3) Cathedral ceilings that need underside insulation. For standard attics with good clearance, blown cellulose or fiberglass offers 90% of the benefit at 30% of the cost.

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See how attic insulation ranks against solar, heat pumps, and 19 other energy improvements.

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