Homeowners typically pay a range for insulation depending on material, thickness, and labor. The main cost drivers are material type, installation method, home size, and local labor rates. This guide presents the cost comparison between spray insulation and fiberglass, with clear price ranges and practical notes to help budgeting.
Assumptions: region, house size, attic vs wall application, and current insulation levels.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Spray foam (open-cell, installed) | $1.50 per sq ft | $2.25 per sq ft | $3.50 per sq ft | Typically installed in cavities or above ceilings; per sq ft based on attic or wall area |
| Spray foam (closed-cell, installed) | $2.50 per sq ft | $3.75 per sq ft | $7.00 per sq ft | Higher R-value; often required for moisture barriers |
| Fiberglass batt (installed) | $0.75 per sq ft | $1.25 per sq ft | $2.50 per sq ft | Typically lower installed cost; varies by thickness and cavity depth |
| Installed cost range (whole-house project) | $1,000 | $2,500 | $8,000 | Assumes 1,500–3,000 sq ft; attic and walls mix |
Overview Of Costs
Spray insulation generally carries higher upfront costs but may deliver stronger air sealing and higher R-values per inch. Fiberglass offers lower first-cost options and faster installation in many cases. The exact price depends on the area being insulated (attic, walls, crawlspace), the chosen product, and whether gaps or existing moisture issues require remediation.
For open-cell spray foam, expect a typical installed range of about $1.50-$3.00 per sq ft, averaging around $2.25 per sq ft. Closed-cell spray foam usually runs higher, roughly $2.50-$7.00 per sq ft, with common projects landing near $3.75 per sq ft. Fiberglass batt, installed, commonly costs about $0.75-$2.50 per sq ft, with averages near $1.25 per sq ft. The per-square-foot approach helps scale budgets for various home sizes and room configurations.
Price by application type matters: attic insulation can differ from wall insulation due to access, ventilation, and required air barriers. If a project spans both attic and exterior walls, total costs reflect a blended per-area estimate and any required remediation like moisture control or pestproofing.
Cost Breakdown
| Category | Spray Foam (open-cell) | Spray Foam (closed-cell) | Fiberglass Batt | Assumptions |
|---|---|---|---|---|
| Materials | $0.80-$1.60 / sq ft | $1.40-$3.00 / sq ft | $0.25-$0.75 / sq ft | Includes resin or glass; excludes labor |
| Labor | $0.50-$1.20 / sq ft | $0.90-$2.50 / sq ft | $0.40-$0.90 / sq ft | Install time varies by thickness and cavities |
| Equipment | $0.05-$0.20 / sq ft | $0.05-$0.25 / sq ft | $0.02-$0.10 / sq ft | Spray machines, PPE, containment |
| Permits | $50-$300 | $50-$300 | $0 | Local building codes may require inspections |
| Delivery/Disposal | $0-$50 | $0-$60 | $0-$20 | Containment and cleanup materials |
| Warranty | $0-$150 | $0-$200 | $0-$100 | Material and workmanship considerations |
| Contingency | 5-10% | 5-15% | 5-10% | Repairs or remediation if leaks or mold are found |
| Taxes | 6-9% | 6-9% | 6-9% | Depends on state and local rates |
Assumptions: region, specs, labor hours.
What Drives Price
Material R-value and depth drive the base rate for spray foam. Closed-cell offers higher R-value per inch and moisture control, but at a premium. Fiberglass costs depend on batt thickness, density, and whether it is faced or unfaced. Labor efficiency, access to attic floors or wall cavities, and existing insulation levels also affect total cost.
Regional differences influence price: urban markets may incur higher labor and disposal costs, while rural areas can be cheaper but with limited contractor availability. Product choices like air barriers, sealants, and vapor retarders add to the cost in both categories.
Labor & Installation Time
Install time varies significantly by product and home design. Open-cell spray foam typically requires longer application and curing, increasing labor hours. Closed-cell foam can be more time-intensive due to stricter weather and ventilation controls. Fiberglass installation is generally faster, often completed in days for an entire home, depending on crew size and attic access.
For a typical 1,800 sq ft home with attic and some exterior walls, a spray foam job might take 1–3 days per zone, while fiberglass could take 1–2 days for the same scope. Expect higher daily labor rates in high-cost regions, especially for spray applications requiring skilled technicians.
Regional Price Differences
Prices vary by region with notable deltas between urban, suburban, and rural markets. In the Northeast, total installed costs for spray foam can be 10–20% higher than the national average due to adhesive and disposal rules, while the Midwest may run closer to the average. The South often shows lower labor rates but higher humidity considerations that affect material selection. A three-region comparison illustrates typical spreads: Urban (+8% to +15%), Suburban (baseline to +5%), Rural (-5% to -15%).
Real-world examples show that attic-only spray foam tends to be at the higher end of the per-sq-ft range when air sealing and ventilation upgrades are included. Conversely, fiberglass batts in unfinished basements or crawl spaces often stay near the lower end of the installed-cost spectrum.
Real-World Pricing Examples
Three scenario cards illustrate practical budgets for common homes.
Basic: Attic Open-Cell Foam
Specs: 1,200 sq ft attic, open-cell foam, no major prep
Labor: 12–16 hours; Material: $0.80–$1.60 / sq ft; Total: $1,440–$2,000
Assumptions: dry space, standard rafter framing.
Mid-Range: Wall Closed-Cell + Attic Open-Cell
Specs: 1,800 sq ft walls (closed-cell), attic (open-cell)
Labor: 20–30 hours; Total: $4,500–$7,500
Assumptions: full perimeter, 2×4 walls.
Premium: Whole-House Fiberglass + Upgrades
Specs: 2,000 sq ft walls, high-density fiberglass, uncovered attic
Labor: 16–24 hours; Total: $2,000–$5,000
Assumptions: vapor barriers, pestproofing, sealed attic access.
In summary, spray foam offers stronger air sealing and higher thermal performance at a higher initial price, while fiberglass provides a lower upfront cost with quicker installation and simpler remediation. For homeowners prioritizing long-term energy savings and a tight building envelope, spray foam may justify the premium; for immediate, budget-conscious retrofits, fiberglass remains a common choice.
