How to Easily Seal Windows for the Winter Months

Winter is on its way, if it’s not already arrived for you. One of the most cost-effective and easy ways to seal windows for winter is by installing winter window inserts. Insulating your windows for winter doesn’t have to come with costly replacements or extra labor; not when DIY winter window inserts can take all the hassle out of home protection.

Drafty windows can make your home freezing cold in winter as heat flows outside and force your air conditioner to work extra hard in the summer—leading to high energy bills all year long. To learn about the benefits of window inserts and to discover how to seal windows for the winter, both before the cold season and during, continue reading and prepare for immense time and money savings.

How to Seal Windows Before Winter

5 ways to seal windows for winter: weatherstrips, caulk, shrinkwrap, replacement, window inserts

Before winter, you can choose from weatherstripping, extra caulking, draft stoppers, and DIY shrink-wrap kits in an effort to weather seal your windows and reduce the amount of drafts felt over the cold months.

strip of foam weatherstipping used to seal leaky windows in winter

If you want to weatherstrip, measure the perimeters of each window and then add 10% to account for materials. You can choose vinyl, felt, or metal weatherstripping materials. They range widely in price and capabilities so do your research before choosing to ensure you get the right one for your home.

Before applying your weatherstripping, clean your windows, make sure they are dry, and that the outside temperature is at least 20 degrees Fahrenheit. Apply weatherstripping snugly against both the sash and frame. Be careful not to interfere with the operation of the window.

caulk gun used to seal windows in winter

If you choose caulk to seal your windows, first clean them and make sure they are dry. You can apply caulk to all joints in a window frame and the joint between the frame and your wall. Make sure your caulking gun is held at a consistent forty-five-degree angle to get deep into the cracks.

Caulk in one continuous stream to the best of your ability, and if it oozes out of the crack, use a putty knife to push it back in. Caulking is tricky and definitely takes practice. It’s important that you make sure not to skimp on the amount. If the caulk shrinks into the crack, reapply to ensure a smooth bead is formed to seal your cracks completely.

You can also DIY draft stoppers or shrinkwrap kits. It will take a lot of materials—both in the number of tools and the amount of each material—including fabric, scissors, tape, insulating material, shrink wrap, straight pins and, more than likely, a sewing machine. For a DIY draft stopper, you’ll need to measure your windows, cut your fabric, fold it in half, sew seams, turn the fabric tube inside out, add insulation and sew it together.

diy winter window inserts: shrink wrap, double-sided adhesive, caulk, weatherstripping

To shrinkwrap, you need to apply double-sided adhesive on all sides of your window. Cut it to your desired length with a little extra on the sides. Add shrinkwrap to the adhesive starting at the very top and pull it as taut as you can on the way down the window frame. Blow-dry an inch or so away from the wrap until the wrinkles are gone and trim the edges with a box cutter.

Each of these methods is a decent way to reduce drafts and save a little bit on your utility bill during the winter. However, they are all very time-consuming and several can be difficult to install correctly. Not to mention, they can be an eye-sore even if done perfectly.

The easiest, less time-consuming, and most aesthetically-pleasing way to seal your windows will be using a window insert.

Benefits of Window Inserts

closeup of storm window insert sealing windows for winter

Sealing windows for winter is incredibly important, but installing windows in the winter is time-consuming and downright exhausting. It’s cold, requires construction, extra labor, and it really makes your wallet take a hit before the holiday season. Instead of installing brand new windows, you can reduce your hassle and get all the benefits of new windows, with interior storm windows, also known as window inserts.

Window inserts greatly reduce, or entirely eliminate, condensation on existing windows. When you purchase a high-quality insert, it enables homeowners to get energy savings equivalent to standard double-pane windows at 15-20% of the cost. All while nearly disappearing when installed, allowing the aesthetics of original wood windows and the home’s beauty to shine through.

By increasing insulation through the windows, you are able to:

And because of your savings on heating costs, your energy efficiency is improved and your carbon footprint is virtually eliminated.

If your home is older, has some wear and tear, or you live in a harsher climate, then you should consider investing to get it in good shape going into winter. Not only will you be more comfortable through the season, but you will save more in maintenance and energy costs long term. As an added bonus, you will add value to your home.

How to Seal Cold Windows During Winter With Inserts

Many weatherizing solutions can’t be installed during the actual winter. For example, when it comes to caulking, the temperature needs to be higher than 45 degrees Fahrenheit to achieve the best results.

So, if you procrastinated weather protection measures, or if you thought you could get away without, and catch yourself with a draft, caulking, weatherstripping, and other methods will not work for you. And full window replacement can be miserably cold as you will have a hole in the side of your house until the new window can be installed.

Indow® has customized inserts that fit snugly into your existing window frames. Once in the frame, they create an airtight seal that blocks the cold, outside noise, and harmful UV radiation.

Indow uses proprietary software to design compression-fit inserts that fit into virtually any existing window. They can be installed without hardware and are undetectable once in place. Unlike other solutions, Indow inserts are custom made with a laser-measuring system.

Since homes and buildings settle over time, most windows aren’t square. To seal window drafts effectively, Indow custom-makes inserts to be the exact shape of your window frames. The laser measuring system ensures each insert fits every window just right.

The patented compression tubing allows you to easily install or remove your inserts without damaging your existing windows with a mounting bracket or track system. The thermal acrylic increases the surface temperature of your existing windows, which raises the overall room temperature and lowers your energy bills.

Indow window insert installation is incredibly simple. A full installation can be completed in a few minutes per window and there is no construction necessary (so no holes in the side of your home!). If you accidentally waited too long to install inserts during the fall and winter weather has already arrived, no problem. The inserts can still be installed during the cold, harsh winter months from the comfort of inside your home. No more questioning how to seal leaky windows in winter.

  1. Check the label on the insert to make sure you install it on the correct window.
  2. Place the bottom of the insert into the window frame and ensure it is centered correctly, so the compression on one side isn’t stronger than the other.
  3. Push the bottom corners into place.
  4. Continue pushing the insert into place starting from the bottom and going up each side, ensuring even compression as you go.
  5. When you reach the top, push in the insert in the middle of the top and then work your ways out to the corners.
  6. Check the seal all the way around to make sure it’s evenly compressed.
  7. That’s it! Your window is sealed.

Thermal Imaging Proof

Insulating windows for the winter instead of installing new windows in the cold is an easier, quicker, and more feasible solution. Don’t believe us? Check out the thermal imaging one of our satisfied customers took of their home after installing Indow inserts to replace his plastic window kits.

Greg happily told us, “I can see out my windows in the winter and let light in on a sunny day. My house is no longer a dark cave with little light in the winter.” He started by installing Indow inserts in one room to make sure the fit was perfect and to see if they made a difference. After the success of his imaging test, he moved forward with the rest of his windows in his Albuquerque home.

Want to learn more or get started on protecting your windows for the winter today? Check out all of the window inserts Indow offers, or get started on your free estimate today.

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bedroom with window with Indow inserts installed for soundproofing in San Francisco


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Customer Reviews


4.49 Average 1477 Reviews logo

Matthew L

Indow inserts were easy to measure, order and install. They've provided great insulation for old single-pane and stained glass windows in an antique home. We can significantly feel how much better the home holds heat.

Posted 2 days ago

Ellis W

I ordered two Indow inserts for my home. They are doing a great job, entirely happy with them and the ordering process.

Posted 1 week ago

Elizabeth W

I can't say enough good things about this product and company. Our house is 101 years old and the sidelites next to our front door are single pane ancient wavy glass which means when it gets very cold (Chicago temps) we can have an inch of frost covering the INSIDE of our windows. I was desperately searching for a solution so our front vestibule was not so cold and a friend recommended Indow. The process could not have been simpler and the temperature difference it has made is off the charts.

Posted 2 weeks ago

Austin T

I have several historic single pane gridwork mullion windows. They're beautiful but have almost no thermal protection. Indows proved to be the perfect solution to preserve these windows while getting the thermal comfort we need. They were easy to install and work perfectly!

Posted 3 weeks ago

Kathryn M

Amazingly easy to install even the safety chain holders. I. Noticed an immediate sound level difference and the room atmosphere became more solid feeling and pleasant. They also gave an insulating feature to the window drafts are non existent! The house is 50ft off a State highway that is heavily traveled in warmer months I'm confident the indows will handle it. I'm very pleased!

Posted 1 month ago


We ordered the acoustic inserts to help with road noise, and we've been sleeping so much better with them!

Posted 1 month ago

Sienna K

We used the windows inserts in our skylight. They are great! They the horrible drafts and noise out and were cost efficient. My only comment would be to provide better measurement and installation instructions for skylights specifically. It took us a lot of guessing and research to measure and install because skylight directions were not provided and the windows install guide doesn't always apply to skylights. Other than that though great product and I would buy again!

Posted 1 month ago

ted t

Our home was built in the late 1800s and we have spent a lot of money over the last 20+years restoring it.We did not want to replace the windows with modern windows because of the cost and originality. But the single pane windows come with a price also. the main reason we purchased the Indow window inserts is because of the condensation on the inside of the windows.We would literally have a take a towel and wipe them down every morning in the winter. There would be a puddle on the sill,and wood and water dont get along to well. SO we looked into the best solution to our problem and found Indow. Was reluctant to spend that much money but am super glad we did!! They have been installed now for over two months and our condensation problem has been virtually eliminated.!!! AND our furnace does not run as much as it did before. Over all it was money well spent!! The process was a little scary at first but they have a simple formula. And our contact person,Reed was awesome. Answered any questions i had and was always available.

Posted 1 month ago


Used to block interior side of a garden window in the the kitchen. Without insert, cold air literally poured into the kitchen making a winter jacket almost mandatory when preparing meals or washing dishes

Posted 1 month ago

Rob S

Highly recommend! The team (Brian) took time to help me figure out the best solution. They were made and delivered faster than expected. It was very rewarding to install them because I could feel the cold air get squeezed out as they went flush against the single pane of glass. Solid quality and great fit.

Posted 1 month ago

Alexa L

My inserts fit beautifully into my 125 year old windows - many of which were 5 feet tall. Easy to unwrap and install. Great product and even better service! I liked the process of measuring the windows with a laser measuring tool which was easy to use and precise. The product came in good condition after shipping across country and was well marked. The customer support was excellent.

Posted 1 month ago

Sarah D

Received our Indow Windows and can tell they are blocking a lot of the noise we could hear. Right now the weather is mild, but hoping to notice a big difference when the summer heats up. Our house is in a historic district and we cannot change our windows. They are very drafty and thin glass. We only ordered two, but we are in the process of ordering for four more. Love that we don’t need to drill holes or anything and they just pop right in.

Posted 1 month ago

Allan F

Every thing arrived in perfect condition, thanks to the very secure packaging. Windows fit as expected, although quite tight. After installation we noticed that the cold drafts were gone and the room felt a lot warmer. We are very satisfied with the product and the result.

Posted 1 month ago

Adriana W

Great customer service! Super satisfied with our windows.

Posted 1 month ago

Thomas M

Indow service and product is good. Reduced outside noise considerably.

Posted 2 months ago