MARCH 2024
Ultralight Insulating Panels for Operable Windows

Windows, especially single-pane windows, are the weakest energy efficiency link in a building envelope. Secondary windows can improve performance without the expense of window replacement.

Researchers from the Pacific Northwest National Laboratory (PNNL) evaluated ultralight insulating panels that attach to existing windows and maintain window operability. They found that the technology was easy to install and improved the center-of-glass U-factor by 52%.

Download Findings

• 1-page infographic

• 4-page brief

• PNNL full report

View Webinar

• On-demand video

• Slides

• Q&A

Additional Resources

• Presentation: Enhancing Window Performance with Energy-Efficient Attachments (AERC, May 2020)

• Presentation: Secondary Windows Products (NEEA, 2020) found on Lightweight Secondary Windows