How to Winterize Your Windows in 4 Simple Steps

Living in the northern United States, you get to experience all four seasons. For many homeowners in the Midwest, Northeast and Pacific Northwest, winter is the one season they could live without.

Even the mildest of winters bring frigid temps, snow and ice. To keep your home comfortable for an extended cold snap or months in a deep freeze, you need to take extra measures to prep for winter. One of the best ways to hold the heat in and keep the cold out is to winterize your windows.

4 Steps to Winter-Proof Windows

Air can travel in and out of your home anywhere there’s an opening. Most of the year, you may not notice it at all. But in wintertime, you can easily tell that your home is colder and your energy bills are higher. 

Since there are multiple windows throughout your home, there’s more opportunity for you to lose heated indoor air or let in chilly outside air. To minimize the effects of winter on your windows, you need to follow these steps each year to make sure they’re in prime condition and ready for the season.

1. Caulk and seal windows for winter.

The sealant and caulking is critical during the winter. It helps create a barrier between the window frame and the exterior siding. So it is extremely important that the sealant and caulking remain intact and in good condition. 

You need to check out each and every window to ensure everything is in working order and that all seals are airtight — and watertight. While air will make your home cold, water that seeps in and freezes can do even more damage.

Manufacturer-recommended maintenance calls for an annual inspection of your windows. Examine where the exterior of your window meets the house to inspect the seal. Pay close attention to the caulking at the lower corners of the windows and under joints between window combinations, where water is likely to collect. If you spot cracked, dry, broken or brittle sealant, apply new caulking to fix it and rebuild that barrier.

2. Apply new window weatherstripping.

Once you’ve fixed the sealant or assured it’s in good condition, move on to the weatherstripping. Quality weatherstripping should be tight, covering the space between the window sash and frame to reduce air leaks and prevent water from entering your home.

There are a variety of weatherstripping products to choose from, and what you need may depend on the type of window you have:

• Adhesive-backed foam compresses between the window and the sash to seal gaps and leaks. 
• Tubular rubber gaskets are hollow rubber tubes that help seal gaps. 
• Felt weatherstripping is one of the oldest kinds, and still can do the job in a pinch, but it may not last as long. 
• Spring V-seals are metal or plastic strips that create tension seals to help prevent drafts.

In most cases, you can simply unsnap the current weatherstripping and replace it with a new piece.

3. Inspect window locks and latches.

A window that can’t close properly is going to let air and moisture in. Operate each window — open it, close it, lock it, unlock it — to make sure everything is working. If something sticks or is difficult to operate, try cleaning and lubricating it. 

Locks, latches and other closing mechanisms may wear or break with enough use. If a thorough cleaning and lubrication doesn’t do the trick, the mechanism may need to be repaired or replaced. Contact your local window professional to get it fixed or to purchase a replacement part and make the repair yourself.

Once all window locking mechanisms are in working order, firmly close and lock every window in your home. This ensures you get the best possible seal before winter begins.

4. Hang thermal curtains.

Once you’ve completed the maintenance items that help ensure your windows last a long time and stand up to the elements, you can cover your windows to keep the cold out.

Thermal window curtains are heavy and lined with foam to provide additional insulation. They not only help with the cold, they also reduce the noise in your home and block out sunlight. And once spring comes, it’s easy to swap thermal curtains out for lighter window treatments.

Thermal curtains can be hung to your sill or to the floor. Hang them as close to the window as possible so that they trap the cold air coming in before it reaches the rest of the room. You can also try overlapping curtain panels or attaching them more closely to the wall to help prevent the chilly temps from venturing indoors.

Upgrading to Energy-Efficient Windows for Northern Winters

Winterization really comes down to energy efficiency. Sealing, caulking, weatherstripping and properly locking your windows all work to keep your window operating at peak efficiency in the cold winter months.

Over time, you may find that your annual efforts to winterize your windows aren’t paying off like they used to. You feel more drafts and your HVAC system works a little harder to maintain a comfortable temp. That’s when it’s time to consider energy-efficient windows.

Winter is different and more severe in the northern United States. And there are energy-efficient windows specifically designed for this colder climate. These windows provide lower U-factors and higher solar heat gain coefficients (SHGF) than energy-efficient windows designed for hotter, southern climates. This means that they do a better job of insulating against winter temps while allowing in more sunlight to warm your home naturally.

When heat gain and heat loss through windows are responsible for 25%–30% of your heating and cooling energy use1, upgrading to new energy-efficient windows can make a big difference. Talk to a window professional to get a better idea of what your home needs before you face another winter.

1According to the Department of Energy.