If You Can Feel a Draft, You're Paying for It

I was at a house off Maricamp Road last summer. The buyers were a young couple, first home, probably overwhelmed already. The wife asked me about a window in the spare bedroom. She said, "You can feel air coming through it. Is that a problem?"

It is. It's two problems, actually, and both of them cost money.

What that draft is doing to your AC

A Florida AC unit fights a relentless battle from May through October. Adding a steady leak around the windows is like running the unit with the door cracked open. The thermostat keeps reading warm. The compressor stays on longer. Your power bill quietly creeps higher month after month.

I've seen homeowners drop $250 to $400 a month in summer power bills in central Florida. Some of that is the rate, some of it is the size of the home, but a real chunk of it is air infiltration. Windows and doors that aren't sealing well are a top source.

You don't always need new windows to fix it. A lot of the time we're talking about weather stripping that's dry-rotted, or sash locks that aren't pulling the window tight to the frame, or caulking around the exterior that's cracked and pulled away from the siding. Those are inexpensive fixes that pay back fast.

The water side, which is worse

Air leaks at a window almost always mean water leaks at a window. Maybe not in a normal rain, but in one of those sideways summer thunderstorms we get, water is going to push through the same gaps the air came through. Then it sits inside the wall cavity.

I find this damage usually as a soft spot in the drywall under the window, or as paint that's started to bubble at the bottom corner of the casing. Sometimes there's a brown stain on the sill. By the time you can see it inside, the wood framing behind it has been wet on and off for a year or more.

That's the repair that costs real money. Replacing a window costs a few hundred dollars per opening. Replacing rotted framing, drywall, and a portion of siding around a window costs ten times that, easy.

What I check at every window during an inspection

I open every window I can reach. If it doesn't open, that goes in the report. Sometimes the seller painted them shut, sometimes the sash cords are gone, sometimes the lock is just stuck. I also close every one I open and make sure the lock engages. A window that won't lock isn't just a security thing, it's a sealing thing too.

I look at the glazing, the seal between the glass and the frame. Cloudy glass between panes on a double-pane window means the seal has failed and the inert gas leaked out. It's not dangerous, but it's not insulating like it used to.

I run my hand around the perimeter on a windy day if there's any breeze outside. Or I'll sometimes use a thermal camera if the house feels like it's bleeding cool air. The temperature difference shows up immediately.

I check the exterior caulking. Florida sun cooks caulk faster than most places. A bead that was put down five years ago in this climate is probably already cracked along the top. New homeowners are surprised how often this is the actual leak source.

I check stucco where it meets the window. Hairline cracks here are common and a lot of them aren't a problem. Bigger ones, or ones with rust staining, can mean the metal lath behind the stucco is corroding and the wall behind it has been wet.

Florida-specific stuff

Hurricane wind ratings matter for insurance discounts. If your windows are impact-rated, that affects what you pay. I note that in the report. If they're not, that's something you can budget for if you want the discount, although it isn't a small project.

Single pane vs double pane is more meaningful here than people think. The reason isn't really the cold. We don't have much winter heating load. It's the cooling. A double-pane window with low-E coating handles sun differently than a single-pane window does, and that shows up directly in your power use.

What a homeowner can do this weekend

Walk through and run a hand around every window frame on a windy or rainy day. Anywhere you feel air moving, that's the spot.

Look at the caulking on the outside. If it's cracked or pulled away from the siding, that's a tube of caulk and an hour of your Saturday.

Check the weather stripping on operable windows. If it crumbles when you press on it, it's done. Replacements come in rolls and stick on. Easy.

If you're seeing actual water stains, paint bubbling, or soft spots, that's beyond a homeowner fix. Get someone in to find out how far the damage runs before it gets worse.

A draft is one of those things people learn to ignore. It feels minor. The bill it's running is not.