Understanding the Two Main Insulation Types
What Is Blown-In Insulation?
Blown-in, or loose-fill insulation, consists of small particles that are blown into attics, walls, or floors using special equipment. It creates a blanket of coverage that fills even the smallest gaps and corners — something traditional rolls often miss.
Common materials: Cellulose (made from recycled paper), fiberglass, and mineral wool.
Best for: Attic retrofits, older homes, or enclosed areas where installation by hand isn’t possible.
Average R-Value: R-2.2 to R-3.8 per inch, depending on the material.
What Is Batt Insulation?
Batt insulation comes in pre-cut sheets or rolls, typically made from fiberglass or mineral wool. It’s manually fitted between wall studs, ceiling rafters, or floor joists — making it a favorite for new builds or remodels where framing is exposed. Learn more about how this fits into your broader home upgrade plan by comparing weatherization vs insulation approaches.
Best for: Open walls, basements, and attics in newer homes.
Average R-Value: R-3.1 to R-4.3 per inch, slightly higher than blown-in when properly installed.
Material options: Fiberglass batts (lightweight and affordable) or mineral wool batts (denser, more fire-resistant, and better for soundproofing).
U.S. Department of Energy and EnergyStar.gov both recommend choosing insulation based on access, moisture level, and the condition of your home’s walls and attic.
Blown-In vs. Batt Insulation: Key Comparison
| Category | Blown-In Insulation | Batt Insulation |
|---|---|---|
| Material Options | Cellulose, fiberglass, mineral wool | Fiberglass, mineral wool |
| Best For | Attic retrofits, irregular or enclosed spaces | New builds, open walls or ceilings |
| Installation | Machine-blown, fills gaps easily | Manual install requires cutting/fitting |
| Air Sealing | Excellent coverage, minimal leaks | May leave small gaps if not perfectly installed |
| Moisture Resistance | Moderate (depends on material) | Higher with vapor barrier backing |
| R-Value per Inch | 2.2–3.8 | 3.1–4.3 |
| Cost per sq. ft. | $1.00–$2.00 | $0.70–$1.50 |
| Lifespan | 20–30 years | 30–40 years |
| DIY-Friendly? | No (requires blower) | Yes, for accessible spaces |
Pros and Cons of Each Insulation Type
Blown-In Insulation
Pros: Fills every nook and cranny, perfect for older homes, offers great soundproofing, and can usually be installed in a single day by a professional.
Cons: Not DIY-friendly, can settle over time, and requires expert installation to avoid uneven coverage.
Batt Insulation
Pros: Affordable, easy to install for DIYers, predictable R-values, and simple to replace or upgrade later.
Cons: Can leave gaps around wiring or plumbing, loses efficiency if compressed, and needs vapor barriers in humid areas.
Climate and Home Type Considerations
Climate plays a big role in choosing insulation. Here’s how to match your type to your region. For a complete breakdown of how this works in real homes, read our guide on
how weatherization works.
For Cold Climates
Best choice: Blown-in cellulose or mineral wool. These denser materials trap heat and reduce drafts in frigid regions like the Northeast or Upper Midwest.
For Mild or Moderate Climates
Best choice: Batt insulation. It’s cost-effective, simple to install, and ideal for newer homes in areas like the Pacific Northwest or Mid-Atlantic.
For Humid Climates
Best choice: Batt insulation with vapor barriers or closed-cell spray foam hybrids. These resist condensation and prevent mold in damp coastal or southern regions.
Tip: In wet areas, proper ventilation and moisture control are just as important as R-value. Always seal leaks before insulating.
Cost Comparison and ROI
Here’s what most homeowners can expect to pay:
- Blown-In Insulation: $1.00–$2.00 per sq. ft. (professional installation recommended)
- Batt Insulation: $0.70–$1.50 per sq. ft. (DIY or professional)
Both can lower heating and cooling costs by 15–30%, depending on how well the home is sealed. Typical payback is 3–5 years.
Available Rebates and Incentives
- Inflation Reduction Act (2024–2025): Federal tax credits up to 30% for qualifying insulation upgrades.
- Local Utilities: Rebates from programs like Puget Sound Energy and the Energy Trust of Oregon.
- State Weatherization Programs: Additional support for efficiency retrofits and energy audits, including those for weatherization for mobile homes.
Installation: DIY or Professional?
When to DIY
If your project involves open walls or an accessible attic, batt insulation is a solid DIY option. Just wear protective gear, measure carefully, and avoid compressing the material. Even small gaps can cut performance.
When to Hire a Pro
For blown-in insulation or complex retrofits, bring in a professional. They have the right equipment to ensure even coverage and the correct depth for your local R-value standards. Plus, pros can help with rebate paperwork and energy audits — especially helpful for
commercial weatherization or larger-scale retrofits.
Combining Both for Maximum Efficiency
Here’s a secret: the most efficient homes often use both types of insulation. Batt insulation works beautifully in open wall cavities, while blown-in fills tight attic or floor spaces.
For example, a Seattle homeowner might install fiberglass batts in basement walls and blown-in cellulose in the attic for complete coverage and moisture resistance. This hybrid approach maximizes comfort and minimizes energy waste year-round.
FAQs About Blown-In vs. Batt Insulation
Q1: Which insulation lasts longer?
A: Batt insulation usually lasts up to 40 years if kept dry. Blown-in materials can settle slightly over time but still perform well for decades.
Q2: Can I add blown-in insulation over existing batt?
A: Yes — just make sure moisture barriers are properly managed to avoid condensation between layers.
Q3: Which type provides better soundproofing?
A: Blown-in cellulose and mineral wool excel at sound absorption thanks to their dense structure.
Q4: What’s the most eco-friendly option?
A: Blown-in cellulose, made from recycled paper, is one of the greenest
insulation materials available.
Conclusion: Choosing the Right Insulation for Your Home
Both blown-in and batt insulation can dramatically improve comfort and efficiency — it’s all about matching the type to your home’s design and climate.
Choose blown-in insulation for older homes, attics, or enclosed areas where full coverage is most important.
Choose batt for new builds, exposed framing, or DIY projects where you want simplicity and control.
Before making a decision, schedule a home energy audit. A professional can identify where heat escapes, recommend the best materials, and connect you to available rebates. That one step could save you thousands over time — and
keep your home cozy all year long.
Quick takeaway: Blown-in seals better. Batts are easier to handle. The best choice depends on your home’s structure — and sometimes, using both delivers the best of both worlds.
Lily Strauss is an environmental and energy expert based in Boulder, Colorado, with a background in Environmental Science from Stanford and Energy Policy at a London College. She began her career in environmental consulting before moving into energy policy, contributing to major sustainability initiatives with NGOs and the U.S. Department of Energy. Currently a senior advisor at a global climate think tank, she focuses on energy equity and climate resilience. Outside of work, Lily enjoys rock climbing, photography, and urban farming, and is passionate about climate justice and youth education in sustainability.