What does it mean when there's fog between window panes?

Fog or condensation trapped between the panes means the seal on the insulated glass unit has failed, letting moisture in. The glass unit can usually be replaced without swapping the whole window, but it's worth having a professional confirm. Note the date and which window so you can track it.

Do I need to replace a whole window if only the seal failed?

Often no. If the frame is sound, many windows allow the insulated glass unit to be replaced on its own, which is cheaper than a full replacement. A qualified installer can tell you whether the frame and hardware are still in good shape.

How often should weatherstripping be replaced?

Weatherstripping and door seals typically last 5–10 years, far less than the door itself. If you feel a draft or see daylight around a closed door, the seal is usually the culprit. It's a routine wear item worth checking periodically.

Why did my new windows fail faster than expected?

Premature failure is usually about installation or exposure rather than the product. A poor install lets in air and water, and harsh sun or standing moisture accelerates wear. Keeping the installer's details and warranty on file makes it much easier to sort out who's responsible.

How Long Do Windows and Doors Last?

Windows and doors are easy to take for granted until one sticks, fogs up, or lets a draft through every winter. Most last a long time — but a long time covers a wide range depending on what they're made of, how they were installed, and the weather they face.

Here's a realistic picture of what to expect, plus the details worth writing down so you're not guessing later.

Typical lifespans

These are general ranges. A well-installed, well-maintained window in a mild climate can outlast its category, while a cheap unit on a sun-baked, weather-beaten wall can fall short.

Windows

Vinyl windows: roughly 20–40 years. Affordable and low-maintenance, but the frames can warp or discolor with heavy sun exposure.
Wood windows: 30+ years, sometimes much longer if they're kept sealed and painted. They reward maintenance and punish neglect.
Aluminum windows: 20–30 years. Durable frames, though they conduct heat and cold and can suffer in coastal, salty air.
Fiberglass and composite windows: 30–50 years. Often the longest-lasting frame material.
Insulated glass units (the sealed double or triple pane itself): the seal typically holds 15–25 years. When it fails, you'll see fogging or condensation between the panes — a sign the glass unit, not necessarily the whole window, needs attention.

Doors

Exterior steel doors: 20–30 years. Strong, but dents and rust can shorten the life of the visible surface.
Fiberglass exterior doors: 30+ years. Resistant to rot, rust, and warping.
Wood exterior doors: 20–40 years with regular sealing and finishing; less if water gets into the grain.
Interior doors: often outlast the rest of the house's wear items — decades — since they're sheltered from weather.
Garage doors: 15–30 years for the door itself; the opener and springs are separate components with shorter lives.
Weatherstripping and door seals: these wear out far faster than the door — often every 5–10 years — and are usually replaced on their own.

What shortens their life

A few factors do most of the damage:

Sun and heat. South- and west-facing units take a beating. UV breaks down vinyl, finishes, and seals over time.
Moisture. Standing water, poor drainage, and trapped humidity rot wood and corrode hardware.
Installation quality. A poorly installed window or door leaks air and water no matter how good the product is. This is often the real reason something failed early.
Climate swings. Repeated expansion and contraction stresses frames, seals, and caulk.
Deferred maintenance. Cracked caulk, peeling paint, and worn weatherstripping let water and air in long before the unit itself wears out.

Signs something is reaching the end

You don't need to be an expert to notice these:

Fog or moisture trapped between glass panes
Drafts you can feel even when everything's closed
Frames that are soft, cracked, warped, or discolored
Doors and windows that stick, won't latch, or won't stay open
Rising heating and cooling bills with no other clear cause
Visible rot, rust, or daylight around the frame

If you're seeing these, that's the moment to bring in a qualified window or door professional. They can tell you whether you're looking at a repair (new seal, new hardware, fresh caulk) or a full replacement — and that's a hands-on assessment best left to someone who does it for a living.

What to keep a record of

This is where a home record pays off. Windows and doors are easy to forget about until one fails — and by then, the details you'd want are long gone. For each, it helps to note:

Material and type (vinyl, wood, fiberglass, steel) for each window and door
When they were installed or replaced, even approximately
The manufacturer and model, often found on a label or sticker on the frame
Who installed them, and any warranty paperwork or receipts
Warranty terms — many windows carry a limited warranty on the glass seal that's worth knowing before it expires
Any repairs or reglazing done since

Keeping this in one place — like a profile of your home in Jack's View — means that when a window fogs up or a door starts to drag, you can instantly see how old it is, who to call, and whether it's still under warranty. That turns a vague I think these are original? into a decision you can actually make.

The short version

Most windows last 20–40 years and most exterior doors 20–30, with fiberglass and well-maintained wood reaching the high end. The sealed glass and the weatherstripping wear out sooner than the frames around them. Sun, water, and a sloppy installation are what cut those numbers short. Keep a record of what you have and when it went in, and you'll know what's coming before it surprises you.