When should a home's windows be replaced? It's a big question, and one that's easy to put off because of replacement costs. But it's a question worth answering, since good windows can actually save you money. Here are a few tips and clues that make it easier to tell when old windows are starting to hurt your energy consumption.
Fogging between the panes
One of the clearest signs is a window that starts fogging up. That points to a sealant that's deteriorated, letting air and moisture get trapped between the panes, which is what causes the condensation. The argon gas inside the sealed unit dilutes as outside air seeps in — and since ordinary air insulates far less effectively than argon, the window loses its energy efficiency. That loss shows up not just in comfort, but in your energy bill too.
If all your windows are roughly the same age and one starts fogging, the others are likely not far behind. That's usually a sign it's time to think about replacing the whole set, since it means the seals are drying out across the board. Leaving it alone just means the problem lingers, your electricity bill keeps climbing, and your comfort keeps dropping.
Check for air infiltration
It's also worth checking the weatherstripping around the frames. Once it wears out, warm air escapes and cold air comes straight in, since there's no longer an effective barrier between inside and outside. To check, hold your hand near the frame — some coolness is normal, but an actual draft isn't. You can also pass a lighter flame near the frame; if it flickers, that's a clear sign the weatherstripping isn't doing its job anymore.
Window mechanism
Has a window become hard to open or close? That usually points to worn hardware and windows that may no longer seal as tightly as they used to — the frame may have shifted, for instance. If a window no longer sits perfectly in its frame, air infiltration is a natural result. It's also worth inspecting the frames themselves, especially wood ones: peeling paint often means the wood is absorbing moisture and starting to rot, which can push the window further out of its frame and compromise its performance even more.
If you're concerned about how well your windows are performing, don't hesitate to bring in renovation experts who can help you weigh the right options. Replacing windows is a real investment, but the payoff comes in lower electricity bills and a noticeably more comfortable home.