Windows · Repair, replace or choose · Updated November 2026
Foggy Windows: Repair the Glass or Replace the Window?
Condensation between the two panes of a double-pane window means the seal around the glass has failed. It does not usually cause damage, but the window insulates less well and the fog will not go away on its own.
Confirm it is between the panes
If you can wipe the fog away from either side of the glass, it is surface condensation, not a failed seal; see window condensation: between the panes vs. room side. This guide covers what to do once you know the seal has failed.
Your options
- Replace the glass unit only. A glass shop or window company replaces the sealed glass unit and keeps the frame. Usually the least expensive fix when the frame is in good shape.
- Replace the whole window. Makes sense if frames are rotted, the window is drafty or hard to operate, or several windows are failing. See the cost to replace 10 windows.
- Defogging services. Some companies drill and clean the space between panes. This can improve the look, but it does not restore the original insulating gas.
- Leave it. If the only issue is appearance, it is safe to wait.
What each option costs
| Option | Typical cost | Limitations |
|---|---|---|
| Replace the sealed glass unit | Double-pane glass $100–$300 per window; typical glass job $180–$412 | Depends on the frame and sash being sound; matching custom sizes can take time |
| Replace the whole window | About $850 per window installed (national average) | Highest cost; also fixes drafts, rot and operation problems |
| Defogging service | Varies | Improves looks; does not restore the insulating gas or the original seal |
| Leave it | None | Slightly lower insulating value; the haze may worsen |
Glass figures from HomeAdvisor's window glass cost guide (updated April 12, 2024); window average from our window cost guide.
Check your warranty first
Many window manufacturers cover seal failure for a set number of years. Look for a label on the window frame or spacer bar between the panes that names the manufacturer, then check the warranty terms. The glass may be covered even if labor is not.
When to call a pro
If more than one or two windows are foggy, frames feel soft, or you also notice drafts or leaks, have a window pro look at the whole house before deciding.
Sources
- HomeAdvisor: Replacement window glass cost, page updated April 12, 2024; accessed November 2026
Cost figures are national ranges from the sources listed above and in our windows cost guide, not a quote from FixFinch or any contractor. This article is general information to help you decide on next steps. It is not an inspection or professional advice; a qualified pro who sees the problem in person can tell you what is actually going on. Calls connect you with an independent service provider in our network. FixFinch is not a contractor and does not perform the work.