The fastest drafty windows fix is new weatherstripping, fresh exterior caulk, and tightening the sash locks, which together cost under $50 per window and cut most drafts for a season or two. Replace the window instead when the glass is fogged between the panes, the frame or sill is soft with rot, the window is single pane, or the sash will not lock, because those problems cannot be sealed and are costing you $30 to $60 per window every winter in heat that goes straight outside.
September is the month to decide. Heating bills around Pittsburgh climb in November, and installers across Westmoreland and Allegheny County are booked through October by the end of this month. Here is how we help neighbors in Irwin and North Huntingdon sort the two.
How do I find out which windows are drafty?
You can test every window in the house in about an hour on a cool, breezy evening. Hold the back of your hand an inch from the sash edges, the meeting rail where the two sashes overlap, and the frame corners. Cold air on your knuckles means a gap. For a better test, move a lit incense stick slowly around the same spots with the furnace fan running. Smoke that pulls sideways marks a leak.
Close the window and try to slide a dollar bill out from under the sash. If it pulls free with no resistance, the weatherstripping is shot. Then look at the exterior caulk line where the frame meets the siding or brick. Cracked or missing caulk is a direct path for wind, and in our climate it fails every five to eight years.
What cheap fixes actually stop window drafts?
Weatherstripping is the biggest win for the money. Peel and stick foam or V strip along the sash channels and meeting rail seals the moving parts in ten minutes for a few dollars. Exterior caulk comes next. Cut out the old bead and run fresh exterior grade silicone or polyurethane around the frame on a dry day above 45 degrees, which here means September, not December.
Check the locks. A sash lock that will not pull the two sashes tight leaves a gap at the meeting rail no matter how good the weatherstripping is, and a new cam lock costs under $10. Window insulation film is the last resort for a window you plan to replace next year. It is ugly and blocks the window from opening, but it can cut the loss from an old single pane unit by a third for one winter.
In our Westmoreland County window jobs, about half the drafty windows people call about can be sealed for a season with weatherstripping and caulk, and the other half are past that point because the failure is inside the unit, not around it.
When do the cheap fixes stop working?
Weatherstripping and caulk fix air moving around the window. They do nothing for heat moving through it. A single pane of glass has almost no insulating value, and a double pane unit that has lost its seal is not much better. You can caulk a single pane window airtight and still feel cold coming off the glass from three feet away.
The fixes also fail when the frame is the problem. Old wood frames swell and shrink with our freeze thaw cycles, so a sash that seals in September has a gap by January. Warped vinyl cannot be shimmed straight. And if the sill is soft, the water that rotted it is still getting in.
What are the signs a window needs to be replaced?
Fogged or cloudy glass between the panes means the insulated glass unit has lost its seal. The argon is gone, moisture is inside, and the window now performs like a single pane. Soft wood at the sill or bottom rail means rot. Push a screwdriver into the sill corner, and if it sinks in, the window is done, and the wall below needs a look before the new unit goes in.
Single pane glass, even with a storm window, is a replacement candidate on its own, and many homes in Greensburg, Monroeville, and the South Hills built before 1980 still have a few. A sash that will not lock or stay up is a draft problem and a security problem. Condensation inside the glass every cold morning and stained drywall under the window round out the list. Our windows page shows the ENERGY STAR rated units we install.
What does a leaky window really cost in a Pittsburgh winter?
The U.S. Department of Energy estimates that heat loss and gain through windows accounts for 25 to 30 percent of residential heating and cooling energy use, and their guide to updating or replacing windows is worth ten minutes. In local terms, a typical Irwin house runs a $180 to $260 monthly gas bill from December through February. If a quarter of that heat goes through the glass and a third of the windows are single pane or seal failed, you are paying $30 to $60 per bad window per winter, or $600 to $1,200 over the 20 year life of a replacement. Replacement does not pay for itself on energy alone, but energy plus comfort plus not repainting a rotted sill every other year usually does.
Repair or replace: a side by side comparison
| Situation | Repair | Replace |
|---|---|---|
| Air leak around a sound double pane window | Weatherstripping and caulk, $20 to $50 | Not needed |
| Sash lock loose or broken | New lock, under $10 | Not needed |
| Fogged glass between panes | Glass unit swap possible on some units, $150 to $300 | Usually yes, especially if the frame is over 15 years old |
| Soft or rotted sill or frame | No lasting fix | Yes, and check the wall below |
| Single pane glass | Storm window or film, temporary | Yes |
| Sash will not lock or stay open | Balance repair on newer vinyl, $75 to $150 | Yes on older wood or aluminum |
| Typical cost per window | $10 to $300 | $650 to $1,400 installed for standard vinyl double hung |
| Expected lifespan of the fix | 1 to 3 seasons | 20 to 30 years |
Last updated September 2026. Replacement pricing is for standard size vinyl double hung units in the greater Pittsburgh area. Wood, fiberglass, bay and bow windows, and full frame replacement with new trim push the number higher.
Why replace windows before November instead of in spring?
Three reasons. The savings start the week the windows go in, and the heaviest heating months are December through February. Installation is better in fall, because caulk and foam cure properly above 40 degrees and the crew is not working around snow. And schedules: fall is the busiest season for every exterior trade in Westmoreland County. Homeowners who call in September get an October install. Homeowners who call in late October are often looking at December. If a full house is more than you want to spend this year, our financing options let many customers do the worst six or eight windows now and the rest next fall, and if the entry door leaks too, our doors service can handle both in one visit.
Frequently Asked Questions
What is the cheapest way to fix a drafty window?
New weatherstripping in the sash channels and a fresh bead of exterior caulk around the frame. Together they cost under $50 per window and stop most air leaks for a season or two. Add a tighter sash lock if the meeting rail has a gap.
Can I just put plastic on my windows instead of replacing them?
You can, and on a single pane window it helps for one winter. The film blocks the window from opening and looks rough, so treat it as a bridge until you replace the unit. It does nothing for rot or a failed frame.
How do I know if my windows have a broken seal?
Look for fog, haze, or water droplets between the two panes that will not wipe off from either side. The insulated unit has lost its gas fill and its insulating value. Some newer windows allow a glass unit swap, but on units over 15 years old, replacement is usually the better spend.
How much does it cost to replace windows in Pittsburgh?
Standard vinyl double hung replacement windows run $650 to $1,400 installed in the greater Pittsburgh area as of September 2026, with most homes landing between $900 and $1,100 per window. Larger units, wood or fiberglass, and full frame replacement cost more.
If a few of your windows fail the tests above, we will come out to Irwin, Norwin, Murrysville, or anywhere in greater Pittsburgh for a free estimate and tell you plainly which to seal and which to replace. Fall schedules fill by October, so call (724) 515 5163 or start on our replacement windows page, and you can read what your neighbors say about us on our reviews page.