Cost of Blown In Insulation: What Homeowners Pay in 2024
The cost of blown in insulation is one of the most common questions homeowners ask before scheduling an energy audit or attic upgrade. Unlike batt insulation, blown-in material conforms perfectly to irregular spaces, fills gaps around joists and blocking, and installs in a fraction of the time. Understanding blown in insulation cost per square foot helps you compare bids and budget your project accurately.
Whether you are estimating the cost to blow in insulation in an existing attic or calculating the cost of blown insulation for new construction, material choice and labor rate are the two biggest variables. This guide breaks down what you will pay and what drives the final invoice so you know exactly how much does blown insulation cost for your specific situation.
Blown In Insulation Cost Breakdown
Cellulose vs. fiberglass blown insulation pricing
The two main blown-in materials — cellulose and fiberglass — differ in both cost and performance. Cellulose runs $0.70 to $1.20 per square foot installed and delivers an R-value of approximately R-3.7 per inch. Fiberglass blown-in averages $0.90 to $1.50 per square foot installed and provides about R-2.5 per inch, meaning you need a deeper layer to achieve the same thermal resistance. For most attic applications where depth is not constrained, cellulose delivers better R-value per dollar.
Labor vs. DIY cost differences
Professional installation for a 1,000-square-foot attic typically runs $1,000 to $2,000 all-in, including materials and labor. DIY installation cuts that to $400 to $700 in material costs if you rent the blower from your insulation supplier, often free with material purchase. The tradeoff is physical effort in a hot, dusty attic and the need to install proper baffles and air sealing before blowing. For walls, DIY is more complex and professional installation is usually worth the cost.
Blown In Insulation Cost Per Square Foot by Area
Costs vary by application area and target R-value:
- Attic floor: $1.00 to $2.50 per square foot for R-38 to R-60
- Existing walls: $1.50 to $3.50 per square foot
- Crawl space: $1.00 to $2.00 per square foot depending on accessibility
- Cathedral ceilings: $2.00 to $4.00 per square foot due to access and limited depth
Regional labor rates affect all of these. Expect prices to run 20 to 30 percent higher in coastal metros like Seattle, Boston, or Los Angeles compared to Midwest markets.
Factors That Change the Cost to Blow In Insulation
Several conditions push the cost to blow in insulation higher. Attics with limited headroom or obstructed access hatches take longer to work in. Existing insulation that needs removal adds $0.50 to $1.50 per square foot for disposal. Air sealing adds $500 to $1,500 per project but qualifies for federal tax credits in most cases.
The depth of coverage required also matters. Building codes in cold climates require R-49 to R-60 in attics, meaning 15 to 18 inches of cellulose. Warmer climates may only need R-30, cutting both material and labor costs significantly.
Is Blown Insulation Worth the Investment?
Most homeowners recoup the cost of attic insulation within 3 to 7 years through reduced heating and cooling bills. The EPA estimates that properly air sealing and insulating an attic can save 15 percent on total home energy costs. At current energy prices, a $1,500 project can yield $200 to $350 in annual savings.
Blown-in insulation also reduces drafts, improves indoor comfort, and can dampen sound transmission between floors. For older homes with little or no attic insulation, it is one of the highest-return home improvement investments available.
Next steps: Schedule a home energy audit to confirm your current insulation levels and identify where air sealing will give the biggest return before you blow in new material. Then get three quotes that specify R-value target, material type, and whether air sealing is included.
