What does window glass replacement cost?
Replacing just the glass unit (called an IGU) in a window with a solid frame costs $150 – $400 per window. A full window replacement — frame and all — runs $450 – $1,200 per window. If your windows look foggy or cloudy between the panes, that's a failed seal, and swapping the IGU often fixes it without touching the frame.
The key question is whether your frame is still square, sound, and draft-free. If yes, IGU replacement is the smart, cost-effective move. If the frame is rotted, racked, or drafty, do the full window.
Why windows go foggy — and what fixes it
| Cause | How to tell | The fix | Typical cost |
|---|---|---|---|
| Failed IGU seal (fogging between panes) | Hazy, foggy, or cloudy appearance between the two panes of glass — not on the surface, but inside the sealed unit | Replace the insulating glass unit (IGU) — the glass sandwich comes out of the existing frame as one piece. Frame stays; new glass goes in | $150 – $400 per unit; same-day or next-day service common |
| Single cracked or broken pane | Visible crack, chip, or break in one pane; may be from impact, settling, or thermal stress | IGU replacement if it's a double-pane unit; single-pane glass replacement if it's an older window | $100 – $300 for single-pane; $150 – $400 for double-pane IGU |
| Frame rot or damage alongside failed glass | Soft wood around the frame, visible rot, water staining on the sill, or the window no longer closes squarely | Full window replacement — installing new glass into a rotted frame wastes the money | $450 – $1,200 per window installed (vinyl); $900 – $2,000 for fiberglass |
| Old single-pane glass (drafty, cold to the touch) | Window feels cold in winter, condensation forms on the interior glass surface, or there are obvious air gaps at the edges | Full window replacement — adding a new IGU into a single-pane frame is not possible; the whole window must go | $450 – $1,200 per window (vinyl double-hung installed) |
| Multiple windows failing at once | Three or more windows fogging up, or an older home where most windows are the same age and starting to fail | Price as a whole-home job — contractors discount 15–25% per window on multi-window orders | $4,500 – $12,000 for a typical 10-window home in vinyl |
Try this first (before you pay anyone)
- Touch the glass in the morning on a cold day — condensation on the interior surface means the seal is gone; condensation on the exterior surface is normal and harmless.
- Check whether the fogging clears on hot, dry days. Temporary haziness that comes and goes is early seal failure; permanent fog that never clears is full seal failure.
- Look at the spacer bar between the panes (the metal or foam strip around the edge). If it's visibly corroded, discolored, or has white residue, the desiccant inside has saturated — the seal is done.
- Before calling for a full window replacement, ask specifically whether an IGU swap is possible — not all window companies offer this service, but specialty glass shops and some replacement contractors do.
Call a pro when…
- The fogging is permanent and won't clear — the seal is fully failed and the IGU needs replacement
- You have a broken pane that's creating a security or weathering issue — board it temporarily and call same day
- Multiple windows in the same age cohort are starting to fog — get a whole-home assessment and multi-unit bid
- The frame shows any signs of rot, soft spots, or the window no longer operates smoothly — frame failure needs a full replacement, not glass-only
IGU swap or full window replacement?
An IGU swap is the right call when the frame is solid, square, and still seals well — you're paying $150 – $400 instead of $450 – $1,200 for the same functional result. A full window replacement is the right call when the frame is rotted, the window doesn't close or lock properly, you're upgrading from single-pane to double-pane, or the style of window doesn't match your home's needs (bedroom window that can't open far enough for egress, for example). If you're replacing 4 or more windows, get a whole-home bid — the per-unit price drops significantly.
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Related questions
Can foggy window glass be fixed without replacing the whole window?
Yes — if the frame is sound. A glazier or window specialist replaces just the insulating glass unit (IGU) inside the existing frame. This costs $150 – $400 per window versus $450 – $1,200 for a full replacement. The frame stays; only the glass sandwich is swapped.
Why is my window foggy inside?
The moisture seal around the insulating glass unit has failed. Double-pane windows have a sealed space between the panes filled with air or argon gas. When the perimeter seal breaks, humid air enters, and the desiccant inside gets saturated — resulting in permanent fog or haze between the panes.
How long does an IGU replacement last?
A new IGU in a solid frame should last 15–25 years — roughly the same as a new window. The failure rate on replacement IGUs is no higher than new windows because the seal chemistry is the same; the only variable is the age of the frame.
Is foggy window glass an emergency?
No — fogging between the panes is a comfort and energy problem, not an emergency. Water is not entering your home. It can wait for a scheduled appointment. A broken pane with a gap to the outdoors is urgent; fog is not.