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Keep Temperatures Comfortable & Save Energy with Insulating Window Inserts

Custom Window Inserts Create Comfort

Drafty windows make your home cold in winter as heat flows outside. In summer, they force your air conditioner to work extra hard — leading to high energy bills all year. Window replacement is one solution, but it can be expensive and disruptive. For homes built before 1978, it also carries the risk of lead paint contamination. Insulated home windows make a huge difference in comfort and energy savings and can be as easy as installing window inserts.

Diagram of how to install indow insulating window inserts

Whether you're trying to keep historic windows to preserve the value of your home or want to enhance the performance of newer windows, Indow inserts will regulate the temperature to make you comfortable year-round.

Closeup of window insert used to seal draft.

How to Seal Window Drafts Effectively

Our acrylic inserts are edged with a soft, patented silicone compression tube that presses into the interior of your window frames to seal drafts. You'll feel warmer in winter and cooler in summer, while saving up to 20% on your energy bills.

Unlike other solutions for insulating windows, Indow inserts use a proprietary software, Measure by Indow. We designed this to check the accuracy of window measurements. Going through this process ensures a precise, snug fit for your custom window insert. Why does this matter? Since homes and buildings settle over time, most windows aren't square. To seal window drafts effectively, we custom-make our inserts to be the exact shape of your window frames. Our measuring system ensures each insert fits every window just right.

Our 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. Another benefit? Due to the airtight seal, Indow inserts often reduce or eliminate window condensation.

Data Driven Results

average percentage saved on heating & cooling bills

20%

30%

15%

INDOW

REPLACEMENT WINDOWS

Testimonials

Indow window guide - research by topic.

Customers see immediate benefits

Read what our customers are saying about insulating drafty windows with Indow:

“As soon as they installed the Indow inserts, the chill disappeared. The Indow inserts were the missing piece that made my home both comfortable and energy efficient,” raves one consumer.

Our inserts have even been featured twice on This Old House! Read more case studies on how our Indow window inserts can effectively block drafts to create coziness in your home.

Indow window insert compression tube color samples.

Customize Your Insert

Each insert has a tube that edges the clear acrylic. This tubing should blend into your window frame. It comes in three colors: white, brown, and black.

All our acrylic interior storm windows are durable, lightweight and made to blend seamlessly with the surrounding frame. Don't buy new windows. Make the ones you have just right with our precision measuring software, which will ensure a tight fit for your new window inserts. Just choose the grade you need and get started measuring. We're here to help at every step.

  • Popular Mechanics
  • Dwell
  • This Old House
  • Treehugger
  • The New York Times

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

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Customer Reviews

Excellent

4.49 Average 1479 Reviews

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Anonymous

Don't be afraid of buying an older home with single pane windows. This company has you covered. Their inserts are super high quality and fit well thanks to the laser measuring kit they send. Highly recommended!

Posted 5 hours ago

Katie M

We purchased three Indows to reduce drafts and noise in our bedroom, which faces the street. The improvement was immediate. Our house was built in 1958 and although we have exterior storm windows we didn't want to replace the windows outright due to cost and architectural consistency. These were an excellent solution.

Posted 1 day ago

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 4 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 2 weeks 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 4 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

Anonymous

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

Anonymous

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 2 months 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 2 months ago