winter window insulation

Posted On: January 3, 2020

How To Insulate Windows During The Cold Winter + When You Should Replace Them

If your house feels drafty or chilled in the cold winter months, your first instinct may be to crank up the heat. Before you do, have you checked your windows? They may just be the number one culprit of a chilly house in the winter, especially if the windows are old or poorly insulated. But don’t worry, there are some things you can do to remedy the situation and insulate your windows during the cold months without the need for a full window replacement just yet.

How to Find a Draft

Not sure where the cold air is coming into your home? There are a few simple tricks to quickly and easily identify exactly where a draft may be forming.

First, you can use a candle or matchstick and carefully hold it near your windows while watching for the flame to flicker. You can carefully move the candle around the shape of the window—if the flame blows towards you, your window has a draft. Mark the spot you noticed the candle flicker, so you know to ensure that area is sealed well when you go back and insulate.

You can also use your hand to feel around the windows for a draft. Getting your hand wet with cold water can be especially helpful as it will boost the sensitivity of any cold air hitting the water on your hand.

DIY Window Insulation

Older homes can have very drafty windows, and replacing them can be very expensive. So these insulating tips can help prolong the need to replace all the windows but still boost efficiency and keep your home warm during the cold winter months.

Weather Stripping

You can purchase weather stripping tape at your local hardware store. They come in long rolls with an adhesive strip on one side and foam or rubber on the other. This is one of the easiest ways to seal your windows, and you can do it in a day depending on how many windows you need to seal.

First, determine where you want to stick the weather stripping, and wipe it down with a damp cloth or rag to create a clean surface for the adhesive to stick to. Then measure and cut the weather stripping to fit. Simply remove the strip to expose adhesive film and stick it along the edge of each window. Use more or less as needed.

Window Plastic/Insulating Film

One of the easiest, most common ways to insulate your windows is with a window kit or window plastic, many people will call it. Applying the insulation film requires a pair of scissors, a hairdryer, and some attention to detail, and that’s about it! The window kit will come with a double-sided tape adhesive and pre-cut sheets of plastic (that can be cut to fit custom window sizes).

You will line your windows with the double-sided tape on the trim to ensure all gaps are covered. Carefully stick the plastic onto the sticky adhesive making sure to pull it tight. You will then blow-dry it on warm to hot which will shrink the plastic and make it fit tightly over the window. It’s like magic really! When winter is over, simply pull off the plastic and adhesive. Use a product like go-gone for any stubborn stickiness removal.


Another useful method is to re-apply caulk on the inside, or outside of your windows. Caulk can wear away and if your windows are feeling cold and drafty, it may just be time to remove the old caulk and replace it with new. Simply pry away the old materials and wipe the area clean of caulk and debris. Then, carefully apply caulk between the window frame and the siding (if applying outdoors). Let it sit to dry overnight at least.

Draft Blockers

Draft stoppers, or draft snakes as they are often called, are basically a fabric sleeve stuffed with foam or other material that can sit at the bottom of a door or window to block a gap that lets air in. You will often see them double-sided so that it can slide under a door and move as it opens and closes, but remains on the bottom to seal any cracks or gaps in the door.

Insulated Curtains

If your windows already have a window treatment on them, a simple fix to increase insulation is to purchase insulated curtains. Insulated curtains are made of thick material that will block any drafts and seal in the heat to your home. These can work on doors as well. For example, if you have a back door in the kitchen that really lets out a lot of heat, when the doors not in use, simply draw a thermal curtain to seal in the warmth and keep out that cold.

Interior Storm Window

And last but not least, you can always install new interior storm windows. This does require a bit more work, but can be a much more aesthetically pleasing solution to your drafty windows. Made of plexiglass or acrylic, these interior storm windows will fit right into your window frame without affecting the look or integrity of the inside or outside of your home.

If the time comes to where you absolutely must replace your window, check out our window replacement post for tips on how to DIY your own window replacement, or better yet, call a professional to get it done for you. These insulation hacks can get you through chilly winters for a while, but over time the efficiency of your home continues to drop as air leaks and gaps in the windows grow and never get repaired. When that time comes, give us a call at Northface Construction and we can walk you through the steps to get your windows replaced and upgraded.


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