New Jersey homes · Updated November 2026
Signs You Need New Windows: A 9-Point Self-Check for NJ Homes
Check your windows against 9 signs. Each one tells you to repair or to replace. It takes 10 minutes.
Window age in New Jersey, at a glance
Which signs mean you need new windows?
Walk through your home with this list. Look at every window. Note each sign you find, then read the call beside it.
| # | Sign | Repair or replace? |
|---|---|---|
| 1 | Fog or haze between the panes Double-pane glass looks cloudy, and wiping does not help. | Replace the sash or glass unit. The seal has failed, and fog cannot be cleaned out. |
| 2 | Drafts and cold spots You feel moving air near the frame, or the room is cold beside the window. | Repair first if only the weatherstripping or caulk is worn. Replace if the frame is warped. |
| 3 | Hard to open, close or lock The sash sticks, drops, or the lock will not catch. | Repair a lock or balance. Replace if the frame has moved or sagged. |
| 4 | Water stains, soft wood or mold at the frame Paint peels on the sill, or wood feels soft when you press it. | Replace if the wood is rotted. Repair if the cause is only failed caulk. |
| 5 | Moisture on the inside of the glass Water beads form on cold mornings. | Check humidity first. This alone is not a reason to replace. See our guide to window condensation. |
| 6 | Energy bills keep rising Heating and cooling cost more, and no other cause fits. | Replace if the windows are single-pane or 20 years old or more. Seal drafts first if they are newer. |
| 7 | Street noise comes in You hear traffic or neighbors with the windows closed. | Replace single-pane windows. Double-pane or triple-pane glass cuts more noise. |
| 8 | Cracked or broken glass One pane is cracked, and the frame is sound. | Repair the glass. Replace if the frame is also damaged. |
| 9 | The windows came with the house, and it is 40 or 50 years old Single-pane glass, aluminum frames, storm windows added on. | Plan to replace. Windows that old have used up their life. Pick the date, not the emergency. |
Calls follow the repair-or-replace guidance in This Old House, updated June 2026. Your own windows may differ. An in-home look is the best check.
How to read your results
One or two "repair" signs on a few windows is a repair job. Three or more "replace" signs, or the same sign on most windows, points to replacement. If you are unsure, ask for a free in-home measure. We will tell you what we see.
How long do windows last?
Frame material sets the range. Install quality and upkeep move you inside it.
What this means for your home
The Census puts the median year built at 1956 in Union and Passaic counties and 1982 in Somerset County. Original windows in a house built in 1980 are now 46 years old. That is past the range for every frame in the chart. See where your county falls in our New Jersey home age data.
Typical ranges by frame material. Source: This Old House, updated November 2026.
Should I replace or repair my windows?
Match the fix to the fault. A new lock costs far less than a new window. A rotted frame cannot be fixed with a new lock.
Repair when
- One part has failed, such as a lock, a seal strip or a balance.
- Glass is broken but the frame is sound.
- The only fault is worn caulk or weatherstripping.
- Your home is in a historic district with rules on original windows.
Replace when
- Glass is fogged between the panes.
- The frame is rotted, warped or leaking.
- The windows are single-pane or past their lifespan.
- Repairs keep coming back in the same room.
Source: This Old House, updated June 2026. For all your options, see our replacement windows page.
What new windows look like in a real home
4 checks before you sign for new windows
Count the signs
Use the table above. Note which windows and which signs.
Built before 1978?
The EPA lead rule covers window replacement in these homes. Ask for the firm's EPA certificate.
Check the registration
New Jersey home improvement contractors must register with the Division of Consumer Affairs. Ask for the HIC reg.#.
Get it in writing
Every window counted and measured, with the price. See what new windows cost in New Jersey.
Signs you need new windows: your questions
How do I know if my windows need to be replaced or just repaired?
Repair a single failed part, such as a lock, a balance, a seal strip or broken glass in a sound frame. Replace when the frame is rotted or warped, when the glass is fogged between the panes, or when the windows are single-pane and decades old. The table above gives a call for each sign.
How long do windows last?
It depends on the frame. This Old House lists aluminum and wood at 15 to 30 years, vinyl at 20 to 40 years and fiberglass at 30 to 50 years (updated November 2026). Install quality and upkeep change these numbers.
Is foggy glass a reason to replace the window?
Yes, it means the seal between the panes has failed. This Old House says fog alone does not hurt performance much, but the only way to remove it is to replace the sash. Many double-pane glass units carry a fog warranty of about 20 years.
My windows sweat in winter. Do I need new ones?
Not always. Moisture on the inside of the glass often comes from high indoor humidity. Moisture between the panes is the seal failure. Read our condensation guide to tell the two apart.
Do older New Jersey homes need lead-safe window work?
Yes, if the home was built before 1978. The EPA lead rule always covers window replacement in those homes, and the firm must be EPA certified. Ask for the certificate before you sign.
Sources
- This Old House, Signs it's time to replace windows, updated June 17, 2026. Includes the 2025 survey of 1,000 homeowners.
- This Old House, How long do windows last, updated November 3, 2026.
- U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, via our home age by county page.
- EPA, Renovation, Repair and Painting Program for contractors.
Found signs in your home?
Book a free in-home measure. Installation is included. NJ HIC reg.# 13VH11201500.
