Warm-edge spacer
The strip around the edge of the sealed glass unit that holds the panes apart. “Warm-edge” means it's made of a low-conducting material instead of plain aluminum.
What it means for you
The unglamorous part that decides whether your window sweats and fails early at the edges. A better spacer is a genuine quality signal, not a gimmick.
Where you'll see it
Rarely itemized; ask what spacer a window uses when you're comparing two similar quotes.
Related terms
Reading this on your own quote?
Run the 30-second check — where your number lands against real NC ranges, plus the red flags.
Check my quote →