Our Heating Bill Doubled and Every Window Tested Fine

Where Heat Actually Escapes

Look up.

That’s what she told us. Not at the walls, not at the windows—at the ceiling. Specifically, at any access point between your living space and the attic.

We had an attic hatch in the upstairs hallway. A simple square panel, maybe 22 by 30 inches, that you push up and slide aside when you need to store Christmas decorations or check on insulation. We’d lived here four years and honestly never gave it a second thought.

Turns out that hatch was the problem.

Even when it sits flush in its frame, an unsealed attic hatch acts like a chimney in reverse. Warm air rises—everyone knows that—but when there’s a gap-riddled opening straight into a freezing attic, your heated air doesn’t just drift up. It rushes up.

And all winter long, that’s exactly what ours was doing.

But here’s the thing: you can’t always feel it. Standing under that hatch, I couldn’t detect any obvious draft. The air movement was diffuse, steady, not the kind of sharp breeze a window leak gives you.

So how do you actually prove that’s where your heat is going?