Blown-in blanket insulation (BIBS) is rapidly becoming a preferred choice for homeowners, builders, and contractors seeking a superior insulation solution. Its remarkable energy efficiency, exceptional adaptability, and outstanding thermal and acoustic performance set it apart from traditional insulation methods. BIBS creates a seamless thermal envelope by filling wall cavities with dense, loose fiberglass behind a tightly secured mesh, leaving minimal room for gaps or compression. This airtight, uniform layer significantly improves indoor comfort, boosts energy savings, and enhances air quality.
The system’s ability to tightly conform to irregular spaces, pipes, and framing members means fewer cold spots, better humidity control, and superior sound attenuation. As energy regulations tighten and environmental awareness grows, BIBS has emerged as a high-performance, sustainable alternative aligned with modern building practices. In this guide, we explore exactly how BIBS works, its primary benefits, detailed technical specifications, comparisons with other insulation methods, and critical considerations for anyone evaluating insulation options today.
How Blown-In Blanket Insulation Works
Blown-in blanket insulation merges the benefits of loose-fill fiberglass insulation with an expertly installed netting system. First, a breathable yet strong mesh fabric is stapled tightly over wall, floor, or ceiling framing. Next, fiberglass insulation is blown into the cavities at a controlled pressure, completely filling the voids with dense, uniform coverage.
The technique eliminates the compression and voids often associated with batt insulation while also allowing for high-density fills that resist settling over time. The resulting barrier reduces thermal bridging, minimizes air leakage, and boosts sound control in ways traditional batt insulation cannot match.
Advantages of Blown-In Blanket Insulation
- Superior R-Value Consistency: Achieves consistently high R-values per inch across entire surfaces, outperforming batt products.
- Exceptional Fit: Conforms to irregular cavities, around electrical wiring, plumbing, and framing elements without gaps.
- Enhanced Air Sealing: Reduces drafts and airborne pollutants by tightly sealing spaces that batt insulation leaves vulnerable.
- High Soundproofing Ability: Densely packed material dampens sound transmission significantly, ideal for multi-family and commercial settings.
- Moisture Resistance: Fiberglass material naturally resists moisture, helping prevent mold, mildew, and rot.
- Environmental Sustainability: Made from recycled materials, contributing to greener, more sustainable construction practices.
Bonus Tip
Request an infrared scan post-installation to verify even insulation coverage and immediately spot any areas needing additional fill.
Technical Specifications
| Feature | Blown-In Blanket Insulation |
| Material | Loose-fill fiberglass |
| Typical R-Value | R-3.7 to R-4.2 per inch |
| Density | 1.8 to 2.0 lbs per cubic foot |
| Application Areas | Walls, floors, ceilings, sloped spaces |
| Fire Resistance | Naturally non-combustible, Class A rated |
| Air Infiltration Reduction | Very low (meets or exceeds ENERGY STAR requirements) |
| Settling | Negligible with professional application |
| Lifespan | 50+ years |
| Vapor Permeability | Highly breathable, minimizes trapped moisture |
Comparison with Other Insulation Types
| Feature | Blown-In Blanket (BIBS) | Spray Foam | Batt Insulation | Loose-Fill Cellulose |
| R-Value per Inch | 3.7–4.2 | 6–7 | 3.1–3.8 | 3.2–3.8 |
| Air Sealing | Excellent | Excellent | Moderate | Moderate |
| Installation Cost | Moderate | High | Low | Low-Moderate |
| Moisture Resistance | High | High | Moderate | Low |
| Application Ease | Requires skilled installation | Professional only | DIY possible | DIY or professional |
| Soundproofing | High | Very High | Moderate | High |
| Chemical Sensitivity | Low | High | Low | Low |
| Environmental Impact | Low (recycled content) | Moderate to High | Moderate | Low |
Integrated Market Data
According to Grand View Research’s 2024 report, the global insulation market is forecast to grow at a CAGR of 6.2%, reaching $97.5 billion by 2030. Fiberglass-based products like BIBS represent nearly 45% of this expanding market share. Concurrently, the U.S. Department of Energy states that upgrading to high-efficiency insulation methods like BIBS can reduce residential heating and cooling bills by up to 30%. Furthermore, consumer surveys indicate that energy-efficient insulation upgrades rank among the top five priorities for home improvement spending in 2025.
Things to Consider Before Making a Decision
Project Type and Accessibility
- New construction projects allow for faster, simpler installation of BIBS into open cavities.
- Retrofitting projects may involve partial or full removal of drywall, increasing cost and labor requirements.
Budget Planning
- BIBS sits between batt and spray foam insulation in terms of price.
- Energy savings over 5–10 years often offset initial installation costs.
Moisture Management
- Assess local humidity levels and building envelope conditions.
- In humid climates, consider pairing BIBS with vapor barriers or vapor-retarder paints.
Installer Qualifications
- Proper BIBS installation demands specialized training and equipment.
- Verify contractor certifications and request references or previous project examples.
Climate and Energy Code Requirements
- BIBS performs exceptionally well in extreme climates, improving HVAC efficiency.
- Ensure compliance with local building codes, which may mandate minimum R-values that BIBS can meet or exceed.
Bonus Tip
Ask your insulation contractor for a “bag count” or material usage report after completion to confirm full coverage according to manufacturer standards.
Common Questions About Blown-In Blanket Insulation
Can BIBS be used in ceilings and floors? Yes, BIBS is highly effective in walls, ceilings, and floors, especially in areas where soundproofing or maximum thermal performance is critical.
Is BIBS better than spray foam insulation? BIBS and spray foam both excel in performance but differ in priorities. Spray foam has higher R-values and air sealing capabilities, but BIBS offers comparable performance with lower chemical exposure and environmental impact.
What type of maintenance does BIBS require? Once installed properly, BIBS requires little to no maintenance. Regular building inspections can help ensure that wall systems remain intact.
Will BIBS settle or lose effectiveness over time? Correctly installed BIBS has negligible settling and maintains its insulating properties for the lifetime of the structure.
How long does a BIBS installation typically take? For standard single-family homes, installation usually takes 1 to 3 days, depending on the size and complexity of the project.
Blown-In Blanket Insulation FAQ
How much more energy-efficient is BIBS compared to traditional batt insulation?
Studies show BIBS can deliver up to 30% greater energy savings due to superior air sealing and continuous coverage compared to batt systems.
Does BIBS help reduce noise in multi-unit buildings?
Yes, BIBS is highly effective for noise reduction, making it an excellent choice for apartments, duplexes, and mixed-use buildings.
Is BIBS a good option for green-certified buildings?
Absolutely. Many BIBS systems use recycled glass content, help reduce overall building energy consumption, and contribute credits toward LEED and other green certifications.
What happens if BIBS is installed incorrectly?
Poor installation can lead to uneven fill, thermal gaps, and reduced system performance. Always choose certified, experienced contractors.
Are there specific standards BIBS installations must meet?
While building codes don’t always reference BIBS by name, insulation installations must comply with specified R-values and air sealing requirements as outlined by the International Energy Conservation Code (IECC) and local standards.
Make the Right Decision
Choosing blown-in blanket insulation can dramatically improve a building’s energy efficiency, interior comfort, sound quality, and long-term sustainability. Carefully weigh the needs of your project, your local climate, and your performance goals. Partner with a qualified installer, verify adherence to best practices, and monitor installation quality. With thoughtful planning and execution, a blown-in blanket insulation system can offer lasting value and measurable improvements in building performance for decades to come.