Fogged windows on a home inspection: what to ask for

What do fogged windows on a home inspection mean?

A fogged window means the seal around the air space between its panes has failed, and it needs new glass or a whole new window. Ask the seller to replace the sealed glass in each fogged window, priced on a glass company's written bid. The International Association of Certified Home Inspectors (InterNACHI) says a foggy double-pane window "has failed and needs to be repaired or replaced."

Key takeaways

• Ask for the window brand and warranty papers: seals may be guaranteed for three to 15 years.
• New glass and labor for three fogged windows runs $750 to $3,300 or more at Bob Vila's national figures.
• Defogging is cheaper, but the seal stays broken. Don't accept it as the fix.

How much does it cost to replace a fogged window?

The figures differ mostly by scope: new glass in the old frame, or a whole new window.

Kept prices every line of an inspection report for $79, usually under 4 hours, and marks the ones that need a professional quote.

Here is one report priced at Bob Vila's national figures. Say the inspector flags three fogged windows, and each needs only new glass.

• One window: $100 + $150 = $250 at the low end, $600 + $500 = $1,100 at the high end.
• Three windows: 3 × $250 = $750 at the low end, 3 × $1,100 = $3,300 at the high end, or more for large or high-end glass.

Bob Vila says the glass price depends "on the size and quality of the window," so a glass company's written bid sets your real figure.

How serious is a broken window seal?

The window has stopped doing its job, and it won't recover. Once the seal breaks, Bob Vila's guide says, "the problem will persist." Any insulating gas between the panes "is now gone."

Left alone, InterNACHI says the condensation "will inevitably lead to irreversible physical window damage." Water can carve grooves into the glass, and worn-off silica gel from inside the window can collect on it as white "snowflakes." InterNACHI adds that "it is believed that if this damage is present, the window must be replaced."

Can a fogged window be fixed, or does it need replacing?

Usually the glass gets replaced and the window stays. Industry experts cited by InterNACHI say the sealed glass unit "can be replaced approximately 75% of the time." Sometimes the sash, the frame that holds the glass, has to go too. Only about 5% of those sash cases need an entire new window.

This Old House calls a new insulated glass unit "the most reliable solution for a failed seal." A whole new window makes sense when the window is also hard to open, warped or worn out, Bob Vila says.

Defogging is the cheap option. A company drills a hole in the glass, sprays in a solution, and vacuums the moisture out. This Old House says it "doesn't restore the seal or replace the lost insulating gas." Bob Vila calls it "a temporary fix."

Who can price it before my deadline?

Call a glass company or window repair contractor. Bob Vila says the job "should usually be done by a contractor who understands how the window comes apart." Ask for a written price per window, for new glass and for a whole window where both could apply. Ask when the new glass can go in, too. Clear Works Glass, a Portland shop, says dual-pane repairs take longer because it has to order the sealed glass unit. How to get repair estimates during the inspection period covers getting bids fast.

Ask the seller for the window brand and any warranty papers. The brand matters twice: the new glass unit is ordered from the window manufacturer, and the manufacturer holds any warranty. Windows may be guaranteed "for anywhere from three to 15 years," Bob Vila says, and the manufacturer "will often provide a new IGU" if the seal fails in that time. You may still pay a contractor's labor, and the warranty covers only a seal that was faulty. Whether it passes to you as the new owner is the manufacturer's answer, so call them.

What do I ask the seller for?

One line per window, each with its scope and trade:

• Replace the failed sealed glass unit in the [room] window, per a glass company's written bid.
• Replace the whole [room] window if the bid finds the sash or frame damaged, per the same bid.

If the seller does the work, ask for the glass company's paid invoice before closing. What to ask for after a home inspection shows how these lines sit with the rest of your list. The buyer repair request letter template gives the wording around them.

What if the seller says no?

Ask for a credit for the bid total instead, and hire the glass work yourself after closing. A credit also helps when the new glass can't arrive before your closing date. Your contract sets the dates and terms for the request, so confirm them with your agent. If the windows sit on a long list of other findings, when to walk away after a home inspection helps you weigh the whole report.

Will a broken window seal fail a home inspection?

A home inspection has no pass or fail. InterNACHI's standards of practice define it as "a non-invasive, visual examination" designed to identify defects. Under those standards, the inspector reports "any window that was obviously fogged" as in need of correction.

Can a home inspector miss a broken window seal?

Yes. InterNACHI says "condensation is not always visible." A recent failure may not show "until the window is heated by direct sunlight," and shaded windows may show nothing. InterNACHI's standards also don't require the inspector to "determine the integrity of multiple-pane window glazing or thermal window seals." Look at every window again at your final walkthrough, with the sun on the glass if you can. Bob Vila says seals on the west and south sides of a home often fail first, so start there.

How do I know what the rest of my report is worth?

Price every line before your deadline, not just the windows. Put your bid time into the lines that need a trade, like the glass, and get a priced list for the rest. Exterior findings on an inspection report covers the other lines from the outside of the house.

If fogged windows are a few lines on a long report, upload it to Kept and spend your remaining days on the bids that need a glass company.

Sources

• InterNACHI, Condensation in Double-Paned Windows
• InterNACHI, Home Inspection Standards of Practice
• This Old House, Window Seal Repair and Replacement
• Bob Vila, What to Do About a Broken Window Seal
• Fixr, Window Glass Replacement Cost
• Clear Works Glass, Window Repair Cost Portland