You know that feeling. Winter in St. Louis, wind whipping outside, and you’re sitting near a window that seems to have its own personal weather system. Cold air is creeping in. A draft you can feel on your neck.
Your first thought? The window must be bad. Maybe the glass isn’t thick enough. Maybe it’s single-pane. Maybe you just need to replace the whole thing.
But here’s something most homeowners don’t realize. That draft probably isn’t coming through the glass at all. It’s coming from around the window.
At Berry Door & Window, we’ve been helping St. Louis families solve these problems since 1969. We’ve seen thousands of homes where the real issue wasn’t the window itself but how it was installed and sealed.
Let’s walk through what’s actually happening and how to solve it.
How Air Infiltration Really Happens
According to the Department of Energy, heat gain and heat loss through windows are responsible for 25% to 30% of residential heating and cooling energy use.
However, a big chunk of that energy loss isn’t through the glass. It’s through gaps around the frame.
Frame Gaps
When a window is installed, a gap is created between the window frame and the rough opening of your house. That gap needs to be filled with insulation and tightly sealed. If it’s not, or if the seal breaks down over time, air moves freely in and out.
Think about it. The window itself might be perfectly fine. Double-pane. Low-e coating. All the good stuff. But if air can slip around the sides, that cold draft still reaches you. And all that window technology becomes kind of pointless.
Aging Insulation
The insulation inside your walls also matters. Older homes, especially, can have insulation that’s settled, shifted, or degraded over the years. When that happens, there’s nothing stopping outside air from moving through the wall cavity and finding its way around your window.
You might feel a draft and blame the glass, but the real culprit is hiding inside the wall, out of sight.
Improper Flashing
Flashing is the material installed around windows to direct water away from the opening. But it also plays a role in air sealing. If flashing is missing, damaged, or installed incorrectly, it leaves gaps. And gaps mean drafts.
All of these issues add up to what experts call window air infiltration. That’s just a fancy way of saying outside air moving into your home through openings around the window unit. And it’s a lot more common than most homeowners realize.
Why Older Homes Experience This More Often
If you own an older home in St. Louis, say, a Craftsman in Webster Groves or a colonial in Kirkwood, you’ve probably felt this firsthand.
Here’s why.
First, original windows in older homes were often installed with materials that have since dried out, cracked, or failed. The caulking from 1972 can’t do much anymore. The weatherstripping has turned brittle. The wood framing may have shifted as the house settled.
Second, older homes weren’t built with modern air sealing standards. Back then, energy was cheap. Nobody worried too much about a little draft. So builders didn’t take the same care sealing gaps that we do today.
Third, over decades of St. Louis weather (hot, humid summers, freezing winters, everything in between), materials break down. The sealant around a window frame might last 10 or 15 years. In a house built in 1960? That sealant is long gone.
That’s why window drafts around the frame issues are so common in older homes. The windows themselves might still be in decent shape. But everything around them has aged poorly.
The Role of Professional Sealing and Insulation
So, how do you fix air leaks around windows?
There are some things you can do by yourself. The Department of Energy suggests a few simple tests. Close a door or window on a dollar bill. If you can pull it out without any drag, you’re losing energy. On a windy day, turn on all your exhaust fans and pass an incense stick around the window edges. If the smoke wavers or gets sucked out, you’ve found a leak.
You can also add weatherstripping or caulk small gaps yourself. For windows you don’t open often, consider shrink-film plastic kits for winter.
But here’s the truth. Those are temporary fixes. For real, long-term results, you need professional sealing and insulation.
A qualified installer doesn’t just put the window in and call it done. They ensure the gap between the frame and rough opening is properly filled, usually with expanding foam insulation designed for windows. They check that flashing is installed correctly. They ensure the exterior caulking is applied correctly and will last.
And they know the difference between window sealing problems that you can see and the ones hiding inside your walls.
At Berry Door & Window, this is our standard practice. Every window we install gets properly sealed, insulated, and flashed. We don’t cut corners because we know that’s where drafts start.
Signs Your Window Installation May Be the Issue
How do you know if your drafts are coming from around the window rather than through it? Look for these clues.
- You feel air around the edges. Put your hand near the sides, top, and bottom of the window frame. If you feel cold air at the edges but the glass feels fine, that’s a classic sign of window air infiltration.
- You see daylight. Check your windows at night from outside. Shine a flashlight around the frame while someone watches inside. If light shines through, air does too.
- The window rattles. Give it a gentle shake. Movement means there’s space between the window and the frame. That space lets air move.
- Your energy bills are high. Even with decent windows, if the window drafts around the frame let conditioned air escape, your HVAC system is working harder. You pay the price.
- The area feels damp or smells musty. Air leaks don’t just bring cold air. They can also bring moisture. Over time, that leads to condensation, mold, or rot around the window area.
If any of these sound familiar, don’t automatically assume you need new windows. You might just need a better seal.
How Proper Installation Stops Air Leaks Long-Term
Here’s the bottom line. The best window in the world won’t perform well if it’s installed poorly.
Proper installation starts with measurement. The window needs to fit the opening correctly, not too tight or too loose. Then comes the insulation. The gap around the frame gets filled with expanding foam or fiberglass insulation designed for windows. That’s what stops air leaks around windows before they start.
Next is the flashing. Installed correctly, it directs water away and also helps block air movement. Then the caulking. Quality sealant on the exterior, applied smoothly and completely, with no gaps.
Finally, there’s the interior finishing. Trim and casing that not only look good but also create one more layer of protection against drafts.
When all of these steps are done right, you get a window that performs as advertised. No drafts. No cold spots. No mystery air sneaking into your living room.
At Berry Door & Window, this is how we’ve been doing business since 1969. The wood windows we offer have aluminum-clad exteriors. The wood is never affected by weather conditions. This means no rotting, warping, or painting every few years.
And we install everything ourselves. That means we’re accountable for the whole process, from the first measurement to the final bead of caulk.
If you’re tired of sitting next to drafty windows, don’t just assume you need replacements. Let us take a look. It might be a simple sealing fix. Or it might be time for new windows installed the right way.
Stop by our showroom at 714 Goddard Avenue in Chesterfield. Or call us at (314) 423-DOOR to schedule a free in-home consultation.
