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 1493 Reviews

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JD

Brian was very helpful & informative. He helped me order the correct windows for my needs. They were shipped with the utmost of care & arrived ahead of schedule. Ultimately, the Indow Windows have been very helpful in muffling unwanted noises & they have helped save on our energy costs. Thank you, Indow Window!

Posted 1 week ago

Cynthia M

Very happy with the reduction in noise. Easy to install and use. Great customer service.

Posted 1 month ago

Juli E

We are thrilled with our Indow window inserts! I'd been on the lookout for a more permanent solution to leaky windows in our third floor living space. I discovered Indow on social media but since then have learned of friends who'd had Indow recommended to them by their rennovation contractor. The entire process went smoothly with friendly reps at hand to talk through questions during measuring, etc. They fit perfectly and help us to maintain the beautiful design of the windows on our 100 year old home! Highly recommend!!

Posted 2 months ago

Jen F

Worth the money!

Posted 2 months ago

Elizabeth H

For townhouse living, this solved my problem with noise from my neighbor's with my kitchen window. A considerable decrease of noise indeed! Measurements were a bit frustrating so I recommend using a laser measurement device and following directions to use a string for the diagonal. They look great and were easy to push into place. I highly recommend as an alternative to buying a new window.

Posted 3 months ago

Anonymous

Easy to install, and instantly stopped drafts and dampened outside noises very effectively!

Posted 3 months ago

Robert C

The process could've been smoother with the sending of the measuring kit. There was a delay with weather in Oregon but then it felt like my kit was still delayed due to other reasons. Most new homes (like mine) have textured paint and it can also be inside your window frames. I measured everything out but I still have little tiny gaps due to the texturing. Not indows problem but just be aware you made need to sand or fill in those gaps yourself to get a perfect seal. I did the acoustic grade inserts and they have reduced some noise but they will not completely block or significantly reduce road noise. This is most apparent with deep or lower frequencies like truck exhausts or modified street racing cars that are quite popular these days. Taking the inserts out to open your windows isn't an easy task. The little metal hook they provide needs to be either bigger or you can attach something to it as a way to leverage yourself. Overall the process was average. I think they're definitely a good option for weatherproofing and some sound reduction depending on the type of windows you have. I would purchase again.

Posted 3 months ago

Shelley C

The process for ordering and installing the Indow Widnow inserts was so easy. They sent the measuring information and it had great instructions. The inserts were delivered by UPS was crushed on one corner, but the company had packed them well, so there was no damage. We installed them the same day. It works best if you have two people completing the installation. We felt the results immediately and are glad we spent the money to make our home just a little more efficient.

Posted 3 months ago

Barry B

The insert fits like a glove and insulates the window! No more frost and condensation on the interior of the window! Thank you for an easy, effective and attractive fix!

Posted 3 months ago

Susan A

The support during the entire process was wonderful, thank you so much for the extra quiet space!

Posted 3 months ago

Volodymyr R

Very good good quality. Overall very satisfied with this product and service. Thanks

Posted 3 months ago

Jane H

Our home was built in 1913 and has beautiful old wavy glass single-paned windows. I’m so glad we were told about Indows and didn’t have to replace the original windows. We live in Canada but had no difficulty placing the order and were very impressed by how accurately the company met its deadlines, including cross border delivery. The Indows inserts blend in perfectly with our home and the existing window frames. You don’t see them unless you’re actually looking for them. But what we did notice was how much warmer the rooms feel the minute the inserts were installed! I can’t speak to any heating bill savings because they just went in this week, but our home feels much, much cozier. Our contractor who took all the measurements and installed the Indows says: “Excellent instructional videos: clear and informative. Very impressed with the design and the product. Overall, the ease of installation is quite impressive. Working with all the staff at the company was great – everyone was very helpful.” I’m already recommending this company to any of my friends who live in drafty older homes and want to reduce their heating/cooling bills and do some good for the environment.

Posted 3 months ago

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 3 months 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 3 months 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 months ago