How Do Leaky Windows Affect Heating Costs?

Old windows visible on a house.

As a homeowner, keeping your home comfortable and warm throughout the winter can be challenging. This is especially true if you have leaky windows.

If you have exhausted all ways of sealing your leaking windows without success, you should consider replacing your windows. Most energy-efficient windows will offer a long-term solution to preventing drafts and regulating fluctuating temperatures throughout your home.

Leaky Windows Let in Drafts

It is essential to know how to seal leaky windows, as leaky windows let in drafts. When there is a draft in your home due to leaking windows, your house will feel colder than would otherwise be. Drafty air can cause you to turn up the heat, raising your energy bills.

As a result of using your heating system more frequently, your system may become overworked while attempting to keep up with warming your home.

Poor Air Quality

Leaky windows can affect the air quality within your home. If gaps exist in your windows, polluted air could enter your home.

The air can be filled with dirt, bacteria, and dust not visible to the blind eye, but your lungs will notice. The build-up from polluted air can cause your heating system to overwork itself, potentially leading to issues down the road and raising your heating costs.

Unstable Room Temperatures

Leaky windows often cause fluctuating room temperatures. Leaking windows can affect how your home is heated. If your thermostat is in a room that feels cold, your heat will kick on more often than it needs to heat it.

You might frequently adjust the thermostat to make your home feel more comfortable, but without success. This is inconvenient, and the constant fluctuation in room temperatures will cause your heating bills to rise.

What Are the Signs of a Leaky Window?

There are various signs to look out for when detecting a leaky window. Pay attention to if there are drafts in specific rooms throughout your home, unwanted outside noise, or if there is condensation between window panes.

There may be more obvious signs, such as peeling paint from moisture damage. You may feel air coming through the closed windows, or there could be stains around leaky windows.

How to Fix a Leaky Window

You can do a few things to help fix your leaky windows.


Caulking is often a good fix for sealing leaky windows. You can fill any small gaps within your window frame by caulking them. This sticky substance will mold between the cracks in your window and fill up any open spaces, sealing the leak.

You can caulk your windows from either the outside or inside. However, be sure you choose a specific caulking for inside or outside depending on where you need to seal the leaky window.

Weather Stripping

Leaks often develop due to worn-out weather stripping. You can simply replace the old weather stripping with newer material. You can find weather stripping supplies at your local hardware store.

To weatherstrip your window, clean your window well and identify any gaps that need to be sealed. You can choose from foam tape weather stripping, felt strips, self-sticking tape, or vinyl “V” strips to seal your window’s leak.

Window Film

You can also find window film at your local hardware store to help fix the leak. Window film is a transparent plastic sheet you can attach to your window panes.

Typically, you can use a hair dryer to help shrink the material and apply the film. Before applying your window film, clean the window. You can use a squeegee to remove dust after cleaning, but ensure you get any excess soap off the window before applying the film.

Draft Snake

A draft snake is an affordable solution to fix a window leak. Often, you will see a draft snake pushed up against the bottom of a door. However, a draft snake looks a little different when on windows.

You can trim the snake to match the length of your window, place it on the window sill, and close your window on the snake. This will help you eliminate unwanted drafts in the short term, but is a temporary solution to improve your leaky window’s efficiency.

Replace Your Windows

If you have tried everything to fix the leak and have seen no success, it might be time to replace your old windows with energy-efficient windows.

A window replacement is a long-term solution to fixing leaking windows. You will need to have a window company come and replace your windows for the best results.

Final Thoughts

Leaky windows can cause a rise in the cost of your energy bills, as your home needs to be correctly heated.

It is essential to address this issue as soon as possible to help keep your home warm throughout the winter and cool during the summer.

We can help with your HVAC system repair, maintenance, or replacement service. To ensure your system is running efficiently, schedule a service today!