How to Safely Run Extension Cords Through Windows

Running extension cords through windows can be convenient, but also dangerous if not done properly. Follow these safety tips to securely run cords while minimizing risks.

Assess the Situation

Before running a cord through a window, determine if it's truly necessary or if there's a safer alternative.

Considerations

• How long will the cord be needed? Is this a temporary or permanent setup?

• What will the cord be powering? High-draw devices like heaters require thicker gauged cords that may not run as easily through a window.

• Is there an outlet nearby? Cords under 30 feet are safer than longer runs.

• Can the cord be run under a door instead? This avoids cutting cords or windows seals.

• Are there outdoor outlet options? GFCI protected exterior outlets are best for permanent needs.

Alternatives

• Extension cord covers - Hide cords against baseboards instead of through windows.

• Power strips - Add outlets inside near the window.

• Install new outlets - Have an electrician add new exterior GFCI outlets.

Prep the Window and Cord

If running a cord through the window makes the most sense:

• Use a heavy-duty extension cord rated for outdoor use. Choose a short, thick-gauged cord with sturdy jacket.

• Check the window seal and weatherstripping. Avoid openings that could allow pests or air inside.

• Use cord covers to prevent cord damage. Select wide covers that won't pinch the cord.

• Keep cords off the ground using hangers to elevate above grass and sidewalks.

Run the Cord Through the Window

Follow these safe practices when routing extension cords:

Open the Window

• Fully open the window to access the top of the sash and sill.

• Remove any screens to make more room to work.

Route the Cord

• Drape the cord over the top of the upper sash. Avoid pinching in the window track.

• Run the cord through the narrow opening keeping the jacket intact.

• Plug appliance end outside first, then route slack through window.

Secure the Cord

• Close window gently on cord jacket, don't pinch actual wires.

• Use tape or clips to secure cord at sill so it can't be pulled loose.

Maintain Safety

To keep window cords safe:

• Don't overload cords - Use within rated wattage to avoid fires.

• Use drip loops - Loop cords below outlet level to prevent water running into plugs.

• Unplug when not in use and utilize cords only when needed.

• Check cord routinely for damage and replace if jacket or plugs are compromised.

• Don't run cords higher than first floor due to fall and trip hazards.

With proper precautions, extension cords can be securely run through windows temporarily when needed. But whenever possible, utilize more permanent wiring solutions for ongoing power needs outside the home.