This image shows the regional annual savings when upgrading to ENERGY STAR qualified windows from either single-pane or double-pane, clear glass windows. With ENERGY STAR certified windows, the interior glass stays warmer, so you can enjoy your window seat even when the temperature outside dips well below freezing. Installing ENERGY STAR certified windows, doors, and skylights can shrink energy bills - and carbon footprints - by an average of 12 percent nationwide, compared to non-certified…