noscript

Standard Grade

What are Interior Storm Windows?

man installing interior window insert.

The Indow Standard Grade interior storm windows are an innovative, cost-effective way to block drafts and noise to make your home comfortable and energy efficient. We designed these inserts to help your existing windows perform like new double-panes all while blending into the frames so they’re nearly invisible. They install in seconds without disruption or mess.

interior storm windows or interior window inserts.

Unlike conventional interior storm windows, our indoor storm windows press inside your existing window frames without a damaging mounting bracket. Save money on energy bills while keeping your original windows to preserve your home’s character and value.

Standard grade custom indoor storm window inserts:

  • Nominal ⅛” thick acrylic glazing.

  • Edged in our patented silicone compression tubing.

  • Made in three different colors - warm white, brown and black.

  • Available in custom shapes like arches and rounds.

How Custom Storm Window Inserts Work

Because houses settle, most windows aren’t square. At Indow, we laser measure every window opening and then custom make each insert, ensuring a precise, snug fit for an airtight seal that blocks drafts. That compression is also what holds the insert in place.

The window inserts blend in and can’t be seen from the exterior of the house, so don’t violate historic district guidelines. People with newer double-pane windows use Indow inserts to enhance their performance.

Standard Grade inserts are suitable for any room. Some homeowners start by installing inside storm windows in their draftiest space and over time buy inserts for the rest of their home.

Testimonials on Custom Storm Window Inserts

Instead of replacing the historic windows in his home, Kester installed Indow Standard Grade interior storm window inserts. He immediately improved the performance of his windows.

“What attracted me to the Indow window insert product was that you don’t mess with your house at all. You just press the inserts into your window frames. There’s no mounting bracket. They’re fitted perfectly to each window so it’s just the pressure gasket that allows you to insert it into the window. They’re light and easy to install and remove again and again.”

For partners Greg and Eddie, using Standard Grade eliminated condensation in their mid-century modern Texas home. But Indow inserts are versatile. For a slightly higher price, our specialty grades offer an impressive array of solutions for the myriad challenges posed by windows whether it’s the need to block sunlight or UV rays or create privacy or quiet.

“I couldn’t be more pleased,” said Greg. “The Indow inserts have a very low profile.”

How Standard Grade Storm Window Inserts Perform:

  • Saves up to 20% on energy, whether winter heating bills or summer air conditioning.

  • 50 percent noise reduction (10-12 dBA) when placed over single-pane windows.*

  • Acoustic Grade is the best option for quieting outside noise and will achieve a 70 percent noise reduction (18.9 dBA) when placed over single-pane windows.

Explore complete performance data here.

What Do They Cost?

Consider the cost and disruption of replacing your windows. A vinyl window averages $66-$87/sf. A wood window averages $71-$109/sf. With Indow inserts averaging between $31-$44/sf MSRP, your window project can cost a fraction of other options.

Standard Grade

$31/sf or just $372 for an average window

Our workhorse interior storm window insert blocks drafts and reduces outside noise.

Performance Grade

$40/sf or just $480 for an average window

Our 4 options in performance grade inserts provide superior protection against noise and light.

Commercial Grade

$44/sf or just $588 for an average window

Industrial strength inserts with a scratch-resistant coating can be cleaned with common products.

When you measure your windows, you’ll have help at every step. First, we have a library of video and written tutorials available. Second, our amazing team is always ready to take your call if you need assistance. Third, our proprietary measurement software will automatically check your measurements as you enter them to ensure a tight, snug fit for your customer window inset.

*Sales tax may apply

Data Driven Results

average percentage saved on heating & cooling bills

20%

30%

15%

INDOW

REPLACEMENT WINDOWS

*We want to ensure our inserts help solve your noise problem. Overall noise reduction depends on the amount of noise coming through your walls, ceilings, floors, doors, and existing windows. Noise reduction will be less when placed over double-pane windows. Read our full Noise Reduction Sheet to learn more.

Get a Free Estimate

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

We value safety and privacy. We will never share, sell, or rent your data to third parties not directly related to your purchase or consideration of our products. Read our full policy here.

Customer Reviews

Excellent

4.48 Average 1399 Reviews

Reviews.io logo

Fayette V

The inserts provided immediate results for the better. The inserts a virtually invisible which was better than expected. The biggest challenges were getting the accurate measurements which I Dow was helpful with and repositioning the blinds. Everything has worked out. We are planning to do this with other windows

Posted 3 days ago

Jamie W

We were excited to receive our Indows, but once we got them in, we were blown away! They match our woodwork almost perfectly. Installing them was far easier than we had anticipated, and we were immediately impressed by the noise reduction, as well as the ability to reduce the impact of the windows on our indoor temperature! Couldn't be more pleased and very excited to be able to add "custom" shapes for the top of our lancet windows.

Posted 1 week ago

Mark H

The acoustic indow window worked better than I expected at blocking out noise. The only thing I didn't like was the shipping company (T-Force Freight). The shipping company was difficult enough that I decided to rent a U-Haul and pick it up at their warehouse.

Posted 2 weeks ago

Venkatesh G

Indow solves my noise problem due to highway traffic. I recommend this company for noise reduce solutions.

Posted 2 weeks ago

Thomas R

The process was simple and easy. I was a little nervous having to measure everything myself...but I got the inserts and they fit in our windows perfectly without any hassle. 1000% recommended.

Posted 2 weeks ago

Dan E

As always with internet purchases, I was holding my breath on my recent purchase of inserts! However, everything suggested by everyone I spoke to via telephone, email and text, was verified when I received and installed my inserts!!! Nothing short of phenomenal; fit, sound deadening qualities, (yet to discover energy savings), and customer service is excellent!! I highly recommend this company and product!!

Posted 2 weeks ago

Anonymous

Good quality window inserts. Easy to install. Unfortunately, doesn't do much to block road noise that I was hoping it would help with. Website is clear on the uses so I can't say it was false advertising, just buyer error.

Posted 3 weeks ago

Tommy J

We ordered 4 Indow Window inserts to see how they worked on our steel casement windows. We are very pleased with the fit and finish, and especially the improvement in wintertime comfort. Steel casements present challenging issues when trying to improve efficiency. The only downside for our installation is it required the removal of the locking and operating hardware to work in concert with our window treatments. The attached photo is during installation with Indow inserts installed on the two left pair; not yet installed on the two right pair. Pretty minimal visual difference! I'm now ordering 17 more inserts for the rest of the house.

Posted 3 weeks ago

Catherine L

Our acoustic window inserts have definitely reduced the amount of street noise coming into our apartment. While we can still hear the train as the engines pass by the noise from the train cars is very muted. Likewise we still hear the drunken club patrons yelling, but it no longer seems like they are in the room with us. Our big negative would be that the blinds we enclosed in the space between our single pane and the insert melted and warped within the first week. I don’t think there was any mention in the directions about the possibility of heat build up and potential consequences. That might be good for people to know.

Posted 3 weeks ago

John W

Finally, a solution that doesn't break the bank and allows you to keep your existing windows. We bought ours primarily for additional soundproofing as our builder used dual-pane glass. It makes a measurable difference - 20 dB. The bonus is the insulation value. It's been a mild spring and our main bedroom at the front of the house facing the morning sun is much cooler. I suspect it will be warmer in winter as well. If you follow the self-measure and installation instructions to the letter, they go in easily. We have floor-to-ceiling windows, so we had massive inserts, but it was still manageable for two people.

Posted 3 weeks ago

Jillian G

The measurement process was overly complicated - I understand the desire to get a tight fit into not perfectly square windwos, but a 17 page manual for something you can accomplish with math felt unnecessary. I also found the interface to be a bit challenging to work with when inputting fractions that necessarily had to be rounded but the system didn't like my entry. Otherwise, the inserts themselves fit well, very tight, noticeable noise reduction. I am so satisfied with them that I am considering placing another order (depending on whether I want to also spend the money to change window treatments).

Posted 4 weeks ago

Michael M

What a great option for old homes with drafty windows! Our home's windows are so drafty that the curtains in our bedroom would move/blow when it was windy out. The communication with Indows was excellent, and our questions were answered promptly. We thought the measuring process would be a pain, and we were worried we would not be accurate enough, but the kit they sent along with the instructional videos made it very easy. The Indows were delivered in a large wooden crate, and they made it through shipping unharmed (just some dirt marks on the silicon tubing, most of it came off with Castille soap, but some dark smudges did remain on the white tubing--our only disappointment). Our windows are huge, so we installed the little safety chain provided and inserting them was a 2 person job. There was a little bit of a learning curve with the first Indow, but we can take them in and out fairly easily now. The fit was perfect, and we noticed a difference in the temperature of our home right away. Our house stayed warmer, our furnace ran less, and our curtains are no longer blowing in drafts. The product looks great, and blends right in with our woodwork! We will definitely order more for the few windows we didn't do, and we would recommend this company and product to anyone.

Posted 4 weeks ago

Lisa I

They really work! While I still hear traffic (mostly trucks and motorcycles) normal car traffic is virtually silenced. I'm still not able to sleep in the room because we get so many trucks I am able to use this room as an office space now, which was my goal. This room was once the noisiest room in my house and now I enjoy coming up here to watch tv. Thank you!

Posted 4 weeks ago

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.