A U-rating measures the rate of non-solar heat transfer through a window assembly, including the glass, frame, and spacers. : Ratings typically range from 0.20 to 1.20 .
: Lower is better. A lower number means the window is a better insulator and keeps more heat inside during winter and outside during summer. Eurocraft Energy Efficiency Features Eurocraft Windows U Rating
: Their windows feature five insulating chambers that prevent thermal bridging—a process where heat flows through poor insulators. A U-rating measures the rate of non-solar heat
The (or U-rating) for Eurocraft windows typically indicates high energy efficiency due to their multi-chambered uPVC construction and insulated glass. While specific U-ratings vary by model and glass configuration, high-performance windows generally aim for a U-factor of 0.30 or lower . Quick Guide to Window U-Ratings A lower number means the window is a