That haze between the panes that you can't wipe off? It means the seal on your insulated glass unit failed and the argon leaked out. Here's the good news a lot of window companies won't tell you: the frame and sash are usually still fine, so you probably don't need to replace the whole window. You need new glass, and that costs a fraction of a full replacement.
In Bellingham in 2026, sealed-unit (glass) replacement runs about $150 to $500 per unit, compared with $650 to $1,400 to replace the entire window. If you've got a few fogged units in good frames, this is the smart, cheaper fix, and we'll tell you straight when it's the right call and when it isn't.
Why double-pane windows fog up.
A modern window has an insulated glass unit (IGU): two panes of glass with a sealed, often argon-filled, air space between them. That seal is what makes the window energy efficient. Over time, and faster in a damp marine climate like ours, the seal can fail and let moisture into the space. You see it as fog, haze, or even little water droplets between the panes that no amount of cleaning will touch. The window still "works," but it's lost its insulating value and it looks bad.
What sealed-unit replacement costs.
| Factor | Price impact |
|---|---|
| Standard double-pane unit | $150 to $350 / unit |
| Large or specialty-shaped unit | $350 to $500+ / unit |
| Low-E or tempered glass | +$50 to $150 / unit |
| Obscure/privacy or grid glass | +$40 to $120 / unit |
| Several units at once | lowers the per-unit cost |
The size of the glass and the type (Low-E, tempered, grids, obscure) drive the price. Doing several at once spreads the trip and lowers the per-unit cost, which is why we often time a batch of fogged units together.
Repair or replace? The honest test.
Sealed-unit replacement is the right call when:
- The fog is between the panes (a failed seal), not on the surface
- The frame and sash are sound, not rotted or warped
- You're happy with the window otherwise and just want the view and the efficiency back
Full window replacement makes more sense when:
- The frame is rotted, the sash is failing, or the window is hard to operate
- It's an old single-pane window and you want real efficiency, not just clear glass
- Many windows are failing at once and you'd rather upgrade the whole house
This comes up a lot in newer neighborhoods like Barkley and the Ferndale subdivisions, where builder-grade windows from the 90s and 2000s are hitting the 15-to-20-year seal-failure window. The frames are usually fine, so glass replacement is almost always the move there.
A lot of companies quote you a new window because that's the bigger sale. If the frame is good, ask for the glass instead.
How the swap works.
- We confirm it's a failed seal and check that the frame and sash are sound.
- We measure the glass and order a matching insulated glass unit, with the right Low-E and any grids or obscure glass.
- When it arrives, we pull the failed unit and set the new sealed unit into your existing sash, sealed clean.
- We check the fit with you. Clear view, no new window needed, often a one-day job once the glass is in.
If it turns out the frame is gone or you'd rather upgrade, our window replacement page and the 2026 window replacement cost guide walk through that path and the pricing.
Frequently asked questions.
How much does foggy window repair cost in Bellingham?
Sealed-unit (glass) replacement runs about $150 to $500 per unit in Bellingham in 2026, depending on the size and the glass type. That's far less than replacing the whole window, which runs $650 to $1,400. It's the right call when the frame is still good.
Can you replace just the glass instead of the whole window?
Yes, as long as the frame and sash are sound. We measure the failed insulated glass unit, order a matching one with the right Low-E and any grids, and swap it into your existing sash. If the frame is rotted or it's an old single-pane window, we'll tell you replacement makes more sense.
Why is there fog between my double-pane windows?
The insulated glass unit has a sealed air space, usually argon-filled, between the panes. Over time, and faster in our damp climate, that seal can fail and let moisture in. It shows up as fog or haze between the panes that you can't wipe off. The fix is a new sealed unit.
Why are the windows in my whole neighborhood fogging up?
If you're in a subdivision built in the 90s or 2000s, like parts of Barkley or Ferndale, the original builder-grade windows are hitting the 15-to-20-year mark when insulated glass seals typically fail. The frames are usually still fine, so glass replacement is almost always the cheaper, smarter fix.
For a free measure and a written, line-item quote on your Bellingham home, request a quote or call (360) 927-0588. We aim to reply within 15 minutes during business hours.