When to Replace Windows
Fog trapped between two panes of glass and a draft along the frame point to different answers on when to replace windows.
One usually means a worn part that a contractor can replace, and the other means the sealed glass itself has worn out. Start by counting how many problems each window has, because that count determines whether a repair still makes sense.
Table of Contents
- When Should You Replace Your Windows?
- Signs You Need New Windows (and Which Ones a Contractor Can Repair)
- The Lifespan of Frames and Glass
- Benefits of Newer Glass and Frames
- Repair vs. Replace: How Do I Know If I Need New Windows?
- Whole-House Replacement or One at a Time?
- What’s the Cheapest Time of Year to Replace Windows?
- The Checklist for a Professional Inspection
- How to Choose the Right Frame, Glass and Installer
- Schedule a Free Window Inspection
- Frequently Asked Questions
When Should You Replace Your Windows?
Replace your windows when the seal between the panes has given out, the frame is soft or warped, or the house still has single-pane glass. One problem on its own, like a cracked pane or worn weatherstripping, is usually something a contractor can repair. When two or three of these problems show up on the same window, replacement usually makes more sense than repeated repairs.
These are the most common reasons homeowners replace windows, with the share of homeowners who gave each reason:
- Better energy efficiency (60 percent)
- Maintenance or repair (48 percent)
- Comfort (47 percent)
- Looks and style (45 percent)
- Home value (41 percent)
Signs You Need New Windows (and Which Ones a Contractor Can Repair)
Some of these signs have a cause a contractor can repair, and others mean the window needs replacing. The table matches each sign to its most likely cause and the usual answer.
| Sign | Common Cause | Repair or Replace? |
|---|---|---|
| Drafts around the frame | Worn caulk or weatherstripping, the sealant and rubber strips around the frame | Repair (if frame is solid) |
| Fog or moisture between panes | A seal that’s given out between the panes | Replace the glass or the full window |
| Window sticks or won’t open | Warped frame or worn hardware | Repair (hardware); replace if frame is warped |
| Window won’t lock | Worn lock hardware or a misaligned frame | Repair (hardware swap); replace if frame is warped |
| Soft or rotting frame/sill | Prolonged moisture exposure | Replace |
| Water stains below the window | Worn caulk or a leak around the frame | Repair if caught early; replace if frame is damaged |
| Excessive outside noise | Single-pane glass or poor seal | Replace (upgrade to double-pane glass) |
| Faded furniture near windows | No coating to block ultraviolet light | Replace with glass that has a low-emissivity (low-E) coating, a thin metallic layer that reflects heat |
| Single-pane glass | Original windows in an older home | Replace |
| Rising energy bills | Heat loss through several windows | Replace (after ruling out other causes) |
Drafts Around the Frame
On a windy day, hold the back of your hand near the edges of a closed window. If you feel moving air along the frame, the caulk or the rubber weatherstripping has likely worn out.
A contractor can re-caulk the outside of the frame and replace the weatherstripping for a fraction of the price of a new window. If the draft comes back after new weatherstripping, or the frame itself has warped, replacing the window usually makes more sense.
Fog Between the Panes
Double-pane and triple-pane windows seal two or three sheets of glass together with an insulating gas, usually argon, between them. When that seal breaks, moisture gets in and fogs the glass from the inside, where wiping can’t reach it.
A contractor can replace the sealed glass alone when the frame is still sound, for far less than a new window, or the whole window when the frame is worn, too.
Windows That Stick or Won’t Lock
A window that’s hard to open or won’t stay up usually has a worn balance, the spring or weight system that holds the sliding part of the window in place, or a warped frame. If the lock won’t catch, the sliding part has often shifted enough that the lock no longer lines up with its catch.
A contractor can replace the springs or the lock without replacing the window. If the frame has warped so the window won’t close flush, though, replace the window. A window that won’t lock is also a security risk, so have it repaired as soon as you can.
Soft or Rotting Frames and Sills
Press firmly on the wood along the sill and the lower corners of the frame. If the wood gives or feels spongy, rot has set in.
Once rot reaches the frame itself, plan on replacing the window.
Water Stains Below the Window
Stained or bubbling paint on the wall below a window means water is getting in around it. The source could be worn caulk on the outside, worn flashing (the metal or membrane strip that directs water away from the window) or a frame that has started to rot.
If a contractor catches the leak early, re-caulking and repairing that strip can stop it. If water has reached the inside wall, have the contractor check the frame and the wall around it for hidden damage before you approve a repair.
Outside Noise and Faded Furniture
Double-pane windows cut outside noise noticeably compared to single-pane glass, and new energy-efficient windows let in less of the ultraviolet (UV) light that fades furniture and flooring.
Most energy-efficient replacement windows include at least one low-E coating.
Single-Pane Glass and Rising Energy Bills
Energy Star certified windows lower household energy bills by an average of up to 13 percent nationwide when they replace single-pane glass.
Higher utility bills can also come from an aging furnace or air conditioner, or from thin attic insulation. But if your windows are single-pane, or your double-pane windows are more than 20 years old, they’re a likely cause, and a home energy audit can show where air is leaking in.
The Lifespan of Frames and Glass
Most windows last 20 to 40 years, and the frame material, the quality of the installation, your climate and the upkeep they get can each shorten or lengthen that.
The window lifespan by frame material runs 20 to 30 years for aluminum, 20 to 40 for vinyl and 30 to 50 for fiberglass, and wood lasts 30 or more with regular painting. The seal on double-pane glass usually lasts only 15 to 25 years, so you may need new glass while the frame is still sound.
Benefits of Newer Glass and Frames
New windows end the drafts and the cold spots near the glass that make a room uncomfortable.
New windows can also support a stronger asking price when you sell. New vinyl windows recover an estimated 74 percent of their cost when the house sells, the fourth-highest return in a national ranking of remodeling cost recovery.
Repair vs. Replace: How Do I Know If I Need New Windows?
Ask for the repair price and the replacement price for the same window in writing, so you can compare them side by side.
When a Professional Repair Makes Sense
- The frame is solid and only one part has worn out, like the weatherstripping, a lock or one pane of glass.
Keep a list of every repair and its date for each window, so you can see when one window keeps needing work.
When Replacement Is the Better Call
- The same window has needed more than one repair in the last few years.
- Several windows show the same signs at once.
Ask the contractor what caused each problem, and get the answer in writing with the quote.
Whole-House Replacement or One at a Time?
You don’t have to replace every window at once. When a storm breaks one window and the rest are solid, a contractor can repair or replace only that one, and home insurance coverage for window replacement usually applies to damage from wind, hail or a fallen branch, though not to wear from age.
Replacing several windows together gives the house one consistent look, and some contractors offer volume discounts on larger jobs because the costs of permits, a dumpster and crew travel are spread across more windows.
A full house is a bigger project, and window replacement cost depends on the frame material, the number of windows and whether the crew removes the old frame or sets the new window inside it.
What’s the Cheapest Time of Year to Replace Windows?
Late fall and winter are often good times to shop for cheap window replacement, because some window companies offer seasonal promotions during their slower months.
Ask each company about seasonal promotions and about discounts for replacing several windows at once, and get quotes from at least three before you choose.
Spring and fall bring milder weather, which keeps the house more comfortable while the windows are out, but contractors can replace windows year-round.
The Checklist for a Professional Inspection
A professional inspection should check the frame, the glass, the hardware and the outside seal of each window for the signs above.
The inspector should give one recommendation for each window, to repair it, watch it or replace it, with the reason, so you can decide which windows to replace first if the budget doesn’t cover them all at once.
How to Choose the Right Frame, Glass and Installer
Once you’ve decided to replace, compare the new windows on three points: the frame material, the glass and the quality of the installation.
Vinyl frames need almost no upkeep, fiberglass keeps its shape through hot summers and cold winters, and wood gives a traditional look but needs regular painting or staining to keep out moisture.
For the glass, look for double-pane or triple-pane glass with an insulating gas such as argon or krypton between the panes and a low-E coating.
Even a premium window underperforms when it’s installed incorrectly, so read each quote line by line. A detailed quote names the brand and model of each window, whether the old frame comes out and what the caulking and sealing work includes. The energy label on each window lists its U-factor, a measure of how much heat passes through, and in the Mid-Atlantic and northern states, look for 0.30 or lower when you compare the best replacement windows.
Schedule a Free Window Inspection
Home Genius Exteriors provides free inspections for homeowners who want a professional assessment of their windows. Their team installs ProVia windows, and every installation is backed by the Genius Limited Lifetime Warranty on workmanship. Call today to schedule your free inspection and get a clear answer on whether your windows need a repair or a full replacement.
Frequently Asked Questions
How old should your windows be before replacing them?
There’s no set age. A 25-year-old window in good shape can outlast a 15-year-old one with fog between the panes, so go by each window’s condition, not the year it was installed.
What is the cheapest time of year to replace windows?
Late fall and winter are often the cheapest, because some window companies offer seasonal promotions during slower periods. Ask about one each time you request a quote.
What to look out for when buying new windows?
Check that the quote includes removing and disposing of your old windows, and get the installer’s workmanship warranty in writing, since it’s separate from the manufacturer’s warranty on the glass and frame.
Do new windows add value to your house?
Yes. Real estate agents estimate that new vinyl windows recover 74 percent of their cost when the house sells. The return varies by market, so ask a local real estate agent what buyers in your area expect.
If I replace only a few windows now, how do I match the look and performance later?
Ask your installer to write down the manufacturer, product line, glass, grid pattern and exterior color so you can match them when you replace the rest. Ask, too, whether that product line is likely to be discontinued, and replace a whole room or a whole side of the house at a time so the windows you see together match.
