Last updated on March 10th, 2024 at 03:03 pm

For the most part, energy leaks or loss around windows (leaks that don’t have to do with the windows themselves: the panes, the construction, the actual unit itself) comes down to two main areas – the frame itself and the insulation around the frame.

Energy can be lost whether the window is brand new and just installed (and thus installed incorrectly) or if the window is older.

If the frame is compromised, the energy is lost through the frame itself, through the gaps in the wood or plastic. In most cases, though, energy is lost through missing or bad insulation surrounding the window itself.  Most of the time, gaps in the siding/fascia between the siding panels and the window unit exist and are stretched during a window install. This loosens th caulk that is holding the fascia and the siding panels together above or around the windows.

Air can easily creep through, and is some cases, water will get through – damaging the wood frame and wetting the insulation. The wet insulation will transmit water down through the window itself and around the window, thus causing rot and additional damage.

The way to stop this is to to stop the leakage. The best way to is to caulk with a weatherproof outdoor caulk that matches the siding color around the window opening. The msot common places to find energy holes are at the top of the window unit, near the fascia and on the sides. Most of the time, a window will settle a little and seal itself on the bottom side. This leads to bigger gaps at the top. To solve this, you would need to add additional insulation between the window and the frame to cover the gap. You would also need to seal the outside with caulk.

Most of the time, you discover something like this during a rainstorm – the most common symptom is water leaking through the window from the top down. Unfortunately caulk will only work when the surface is dry and clean. As a temporary fix, you can place a thin strip of foam backing at the top and around the fascia and secure it with a weatherproof tape, like duct tape. Then when the weather dries up, make your more permanent repair.