What makes Windows energy efficient? Anatomy of an energy-efficient window: Quality Frame Materials: A variety of durable, low-maintenance framing materials reduce heat transfer and help insulate better. Multiple Panes: Two panes of glass, with an air or gas-filled space in the middle, insulate much better than a single pane of glass. Weathersafe Restoration is a Family and Veteran owned contractor that focuses on Windows, Roofing, Siding and Water Restoration. Call today for a FREE In-Home Estimate 651-528-6219