How Long Replacement Windows Last in the Pacific Northwest

Modern vinyl and fiberglass replacement windows are built to last decades, and most of the lines we install carry a lifetime manufacturer warranty on the frame and the glass seal for the original owner. What usually gives out first is not the frame. It is the seal on the insulated glass unit, and in this climate the installation and the exposure decide how long that seal holds.

Knowing which part of a window is failing tells you whether you are looking at a repair, a glass replacement or a new window.

A window is three things, and they age at different rates

When someone asks how long windows last, they are usually asking about one of three parts.

The frame is the vinyl, fiberglass, wood or aluminum that holds everything. Vinyl and fiberglass do not rot or corrode, so a frame that was installed square, flashed correctly and kept out of standing water tends to outlive everything attached to it.

The insulated glass unit is the two or three panes with a sealed air or argon space between them. That seal is the part with a service life. When it fails, moisture gets into the space and you see fog or haze between the panes that no amount of cleaning removes.

The hardware is the rollers, balances, latches, cranks and weatherstripping. These are wear items. They are also the cheapest part of the window to replace, and replacing them is often all a window needs.

A window with a fogged pane and sound everything else is not a dead window. It is a window that needs glass. We wrote about why that happens in why your window seal failed, and the fix is insulated glass replacement in the frame you already have.

How the common frame materials age around here

Aluminum

If your house was built between the 1960s and the early 1980s, there is a good chance it still has aluminum frames. Metal conducts cold straight through, so these frames sweat in winter, the rollers wear out, and the seals are long past saving. Aluminum windows from that era are at the end of their working life now, and new glass in a cold metal frame does not fix what is wrong with them.

Vinyl

Vinyl is the most common replacement window in the Pacific Northwest, and the first big wave of it went into homes here in the 1990s. We still see plenty of those frames sound and square, with nothing wrong but a fogged unit or two. Vinyl does not rot, does not need paint, and holds up well to rain. The trade-off is that it moves a little more with temperature than fiberglass does, and it cannot be repainted if you change the trim color later.

Fiberglass

Fiberglass expands and contracts at close to the same rate as the glass it holds, which is easier on the seal over the long run. It stays stiff in large openings where vinyl can flex. It costs more per opening, and it earns that on big picture windows, tall casements and homes where slim dark frames are part of the look. More on that in fiberglass window replacement.

Wood

Original wood sash lasts a long time where the wood is sound and the paint has been kept up. Where it has not, water gets into the joints and the sill and rot ends the story. On a sound older window we can sometimes fit an insulated unit into the original sash instead of replacing the window.

What shortens a window’s life in this climate

Six things do most of the damage here.

1. Water that has nowhere to go. Wind driven rain finds any gap in the flashing or the sill pan. Water sitting against a frame or in an opening is what turns a thirty year window into a fifteen year window.
2. Clogged weep holes. Those small slots at the bottom of the frame drain the track. When they pack with dirt and moss, water backs up into the frame and sits on the seal.
3. South and west exposure. Seals on the weather side commonly fail years before the ones on the sheltered side, which is why partial replacements are so normal here.
4. A bad install. A window that was shimmed crooked, fastened tight against a warped frame, or set without a sill pan is under stress from day one. Stress on the frame becomes stress on the seal.
5. Indoor humidity with no ventilation. Condensation on the inside glass is a humidity problem, not a window problem, but it soaks sills and rots wood over the years.

What Cory looks for

Cory, the owner, does every estimate himself, and on a window he is checking the parts that predict the next ten years, not just the ones that bother you today. He looks at frame condition and squareness, the sill slope, how the old unit was flashed into the siding, whether the weeps are draining, and how the sash sits when it is locked. If the frame is sound and only the glass has failed, he says so and quotes the glass. If three windows on the weather side are shot and the rest have years left, he quotes three. That is the same read that decides insert versus full frame on a window replacement project.

How to tell where your windows are in their life

• Fog or haze between the panes on one or two windows, everything else tight: glass replacement territory.
• Fog in most of the house, plus sticking sashes and worn hardware: the units are aging out together and full replacement usually costs less than chasing them one at a time.
• Aluminum frames, single pane, condensation running down the metal every cold morning: replacement.
• Drafts you can feel with your hand near the sash, but clear glass: often weatherstripping and adjustment first.
• Soft or discolored wood at the sill or the lower corners: that is rot, and it means the opening needs to be opened up and looked at.

Questions homeowners ask

Do replacement windows come with a lifetime warranty?

Most of the vinyl and fiberglass window lines we install carry lifetime manufacturer warranties for the original owner, covering the frame, the glass seal and the hardware, with transfer terms that vary. Front doors are the exception and carry their own terms. Our own 2-year workmanship warranty covers the installation itself. You get the exact terms in writing with the quote.

Is it worth replacing windows one section of the house at a time?

Yes, and plenty of homeowners here do it that way. The weather side or the coldest rooms go first. We note the exact product and glass package on your quote so the next phase matches what is already in.

My windows are only fifteen years old and one is foggy. Is that normal?

It happens, and it is usually one unit rather than all of them. A single failed seal on an otherwise sound window is a glass job, not a window job. If several fail in the same season, that points to the exposure or the original installation, and it is worth having someone look at the flashing.

Get a straight read on your windows

If you want to know how much life is left in your windows, have someone measure them and tell you. Cory does every in-home estimate himself, there is no commissioned salesperson involved, and you get a written quote within 48 hours. Ask for a free estimate and we will tell you which windows need replacing, which need glass, and which are fine.