Are Energy-Efficient Windows Worth It in 2026?
The savings
Heat gain and loss through windows drive 25-30% of home heating and cooling energy use. Replacing single-pane windows with ENERGY STAR models lowers energy bills by up to about 13% nationwide. In the northern U.S., swapping 10 single-pane windows can save roughly $568 a year; replacing double-pane saves less (around $282).
Is it worth it?
If you still have single-pane or failed double-pane windows, the comfort and bill savings make efficient windows a clear win. If you already have decent double-pane units, replace for condensation, rot, drafts, or looks rather than payback alone.
Spotting an efficient window
Look for the ENERGY STAR label for your climate zone and read the NFRC label's four numbers (U-factor, SHGC, Visible Transmittance, Air Leakage). These let you compare products without relying on marketing.