Windows — problems, causes and costs

Most window complaints don’t need new windows. Find what you’re seeing below. Many are a part, a seal, a warranty claim or a humidity problem, and we say which ones you can handle yourself.

Talk to a window contractor What windows cost

Quick answerWindow problems fall into four groups: the glass unit (fog between panes, failed seals), the hardware (a sash that won’t stay up), the opening around the window (drafts at the frame, rotted sills) and the house itself (condensation from indoor humidity). Only the opening problems tend to be expensive, and even those rarely need a whole new window.

Everything we have on windows: what fails, why, what it costs, and which of it you can handle without calling anyone. Replacement is the most expensive answer to almost every window problem. It’s sometimes the right one, but check the cheaper fixes first.

1Start with what you can see

Before you buyFog between the panesA failed insulating seal. Glass-only replacement is often possible and much cheaper. Often DIYCondensation on the inside in winterIndoor humidity, not window failure. Check a hygrometer before ordering windows. Replaceable partSash that will not stay upBalance hardware, not the window. On most vinyl and aluminum units it’s a part. Diagnose firstDrafts at the frame rather than the sashThe rough opening was never sealed. Fixable without replacing the window. Check the framingRotted wood sill under an older windowLong-term water. Check the framing below before pricing a window. Before you buyOriginal single-pane aluminumPoor performers, but energy savings alone rarely pay back replacement. Often claimableHail damage to window frames and screensOften overlooked on a storm claim while the roof is assessed. Check the warrantyBroken thermal seal still under warrantyMany glass warranties survive a sale. Look for the spacer stamp before paying. Before you payWindows cost: what to expect and what to skipWhat drives the price, and which window jobs you shouldn’t pay for.

2How windows fail

What you see	Usual cause	First thing to try
Fog or film between the panes	The insulating glass seal has failed	Check for a warranty, then price glass-only replacement
Water on the inside of the glass in winter	High indoor humidity	Measure humidity and run exhaust fans
Sash slides down or won’t stay open	Worn or broken balance hardware	Identify the balance and replace the part
Draft around the frame	Unsealed gap between window and rough opening	Pull the interior trim and seal the gap
Soft or crumbling sill	Water sitting on or behind the sill for years	Probe the sill and the framing below

Two adjoining painted house fronts with rows of white-framed sash windows — Photo by Eleonora Patricola on Unsplash.

Older windows and lead paint

Windows in homes built before 1978 are among the most likely places to have lead paint, because friction at the sash creates dust. For paid work that disturbs that paint, hire a lead-safe certified firm.

Rotted sills, drafts or storm damage?Talk to a local window contractor who will check the opening, not just quote new windows.

Talk to a contractor

3What window work costs

The price moves with whether you’re replacing glass, a part, a sash or the whole unit; the frame material; insert versus full-frame installation; the size and height of the opening; and any rot repair. Prices vary a lot by region.

Windows cost: what to expect and what to skip

4Window FAQ

Do I need new windows if one is fogged?

Usually not. The glass unit can often be replaced on its own, and it may be under warranty.

Will new windows cut my energy bill a lot?

Less than most people expect. Replacement rarely pays back on energy savings alone unless you’re in a severe climate. Comfort, noise and condensation are better reasons.

Why is there water on my windows in winter?

Usually indoor humidity condensing on the coldest surface in the room. Measure humidity before blaming the window.

Should I repair or replace an old wood window?

If the sash and frame are solid, repair is often realistic. If the sill and framing below are rotted, fix those first either way.

Written by Jaylan Jones. I Like To Exterior Services earns a referral fee when a call connects to a contractor. See our business-model disclosure.

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