You look at your window from outside, and there’s a hazy, cloudy patch you can’t wipe away. Or you notice the inside of the glass looks like there’s permanent condensation that won’t go away.
That’s not dirt. That’s not bad cleaning. That’s a failed insulated glass unit — and it’s a problem that gets worse, not better. Here’s what’s actually happening and what to do about it.
How Insulated Glass Units Work
Modern energy-efficient windows aren’t single pieces of glass. They’re insulated glass units (IGUs): two panes of glass with a sealed air gap between them. Sometimes the gap is filled with argon or krypton for extra insulation. A spacer bar around the perimeter holds the panes apart and contains a desiccant that absorbs trace moisture.
The whole assembly is hermetically sealed at the edges. As long as that seal stays intact, the air gap stays dry, the glass stays clear, and the window does its job.
Why Seals Fail
IGU seals fail. It’s a question of when, not if. The seals are made of synthetic compounds that degrade over time from:
UV exposure. The sun beats on the perimeter of the seal every day. The compounds break down.
Thermal cycling. Hot days expand the gas in the unit. Cold nights contract it. The seal flexes constantly.
Water intrusion. If water sits at the bottom of the glazing bead repeatedly, it accelerates seal failure.
Installation errors. Bad installation that doesn’t account for drainage or that leaves the seal exposed shortens lifespan.
In New Orleans, humidity and heat shorten the typical lifespan of an IGU. Most residential IGUs last 15-25 years here — and we see them go even faster in older Lakeview and Mid-City homes where the original windows were installed in the 80s.
Why It Matters
A fogged window isn’t just ugly. Once the seal fails, the window stops insulating properly. The air gap fills with humid outdoor air. Condensation forms between the panes when temperatures cycle. Your energy bills go up incrementally. And the moisture inside the unit can damage the glass over time — leaving permanent stains that don’t clean off even after replacement.
The earlier you replace a failed IGU, the cleaner the underlying window frame stays.
Got fogged windows? Text photos of the affected ones to (504) 368-8826 and we’ll quote the replacement.
The Good News: You Don’t Need a Whole New Window
Most homeowners assume a fogged window means they need to replace the entire window. Not so. The frame, hardware, and sash are usually still fine — only the IGU has failed.
We can pull the failed IGU out and install a new one in the same frame. The cost is a fraction of full window replacement, and the result looks brand new.
Cost Range
Replacement IGUs in standard residential sizes typically run $250-$600 installed, depending on the size and any specialty features (low-E coating, argon fill, tempered glass for safety locations, etc.).
Larger windows or anything custom shaped costs more. Send us a photo of the affected windows and a rough size, and we’ll quote the actual numbers.
How Long the Replacement Takes
From the day you accept the quote: about 7-14 days. Most of that is fabrication of the new IGU to your specific size. The install itself takes 30-60 minutes per window.
When to Just Replace the Whole Window
Some situations make full window replacement the better call:
The frame is rotted, damaged, or no longer sealing. If water has gotten into the frame itself, replacing just the glass doesn’t solve the underlying problem.
Multiple windows in a room have failed at once. If a whole row of windows is fogged, the cost difference between IGU-only replacement and full window replacement gets smaller, and full replacement gives you better insulation overall.
You were planning to upgrade anyway. If you wanted to switch to impact-rated glass for hurricane protection or upgrade to a better window line, do it now.
Ready to Get Started?
Star Glass Inc. serves Jefferson Parish, Orleans Parish, and the greater New Orleans metro. Reach us any way that works best for you:
Call or text: (504) 368-8826 Email: glass@starglass.com
Visit us: 1000 Westbank Expy, Gretna, LA 70053