Knauf Ecobatt R-21 HD unfaced fiberglass insulation batts deliver reliable thermal performance across a range of DIY and professional projects. If you require delivery to ID, MT, OR or WA, please select that delivery zone as pricing and delivery to those states may vary.

Key Features & Design

• High-efficiency insulation—R-21 HD performance helps improve thermal comfort while keeping cooling and heating costs in check. Fiberglass insulation is a cost-effective way to increase thermal performance, reducing energy usage and supporting more efficient HVAC operation.
• ECOSE Technology binder—bonded with ECOSE Technology, made from sand and over 50% recycled glass bottles.
• GREENGUARD Gold certified—formaldehyde-free for better indoor air quality.
• Naturally brown, eco-friendly binder—binder made from corn, sand, and recycled glass (no added dyes).
• Soft to the touch, easy to cut, and less itchy—designed for straightforward installation and comfortable handling.
• Minimum 50% post-consumer recycled content—third-party certified to include a substantial recycled material content.
• Excellent sound control—great between floors and interior walls, suitable for bathrooms, kitchens, laundry rooms, family rooms, bedrooms, and theatre rooms.
• Size options (all unfaced batts)—choose the right fit for your project:
  • 5.5" x 15" x 93" — 67.81 sq ft per bag; 7 batts per bag
  • 5.5" x 15" x 105" — 76.56 sq ft per bag; 7 batts per bag
  • 5.5" x 19" x 93" — 85.90 sq ft per bag; 7 batts per bag
  • 5.5" x 23" x 93" — 103.98 sq ft per bag; 7 batts per bag

Knauf Ecobatt fibers help you do more while consuming fewer resources—they’re designed to reduce energy usage, improve HVAC efficiency, and support a greener footprint without sacrificing performance.