Soundproofing a room is a lot easier if you don’t have any holes in the walls. That’s basically what a window is… a giant hole in your wall that is letting in sound. Oh, we know a window is more than that. We put them in our living spaces for some light, some airflow, and a place to set an apple pie when it’s fresh out of the oven. But if you’ve found THIS article, you also are concerned about the window’s soundproofing.

There are two types of windows we run into that need soundproofing:
1.   Windows in an exterior wall letting in outside noise
2.   Windows in an interior wall letting in noise from adjacent rooms

You found the right place. We have the absolute BEST window soundproofing options available today. We can solve just about any issue. In the article below, we’ll dive into how to diagnose your specific noise issue and how to soundproof a window. We’ll also compare DIY and professional window soundproofing options before answering some common questions we get. As always, we’re also available for a conversation if you’d rather call, email, or chat with us to solve your window noise issue.

The first step to fixing a noise issue is to identify the unwanted noise. What’s causing it? Where is it coming from? Sound behaves a lot like water. It’s always looking for the weakest point and will “leak” into any space through even small cracks and openings. For a room, these openings letting in sound are often the windows (and doors).

Windows are often the weak point in a soundproof wall for several reasons:

1. 1. Because sound will find its way through even the smallest gaps, A 1% air gap will cap the amount of sound that a wall will block at about 20 db. Even a closed window may not be sealed properly, especially if its older.
   2. Blocking sound requires density. A single pane of glass is much less effective at blocking noise than a brick wall.
   3. A barrier is only be as strong as its weakest point. If you have a brick wall that blocks 50 dB, and then add a window to it that blocks 20 dB – the total wall’s performance is severely compromised. The math works out that a wall that is 50% bricks (50 dB) and 50% glass (20 dB) actually only blocks 23 dB.

Because of this math, it’s actually quite easy to diagnose external noise in a residential or commercial building getting into a room. Are there windows? Yes? We need to soundproof them.

Remember when earlier I said you found the right place? It’s because we have the absolute best solution to soundproof an existing window. Since the window is the weak point for sound to enter just about any room from the outside, this will be the “go to” solution to keep outdoor noise from getting into your home (bedroom, home office, nursery) or commercial building (conference room, examination room, office).

Steps to Soundproof a Window

1. Confirm that the window is the weak point letting sound into the space. If the room has other openings, such as around a poorly sealed door, sound will continue getting into the room even after soundproofing the windows.
   
2. Check the interior and exterior seal where the window meets the surrounding wall or jamb. Poor seals should be removed and replaced with new acoustical sealant.
3. Measure your windows for Fantastic Frame Window Inserts using our Sizing Guide.
4. In your typical window, a Fantastic Frame insert takes about 30 minutes to install and will reduce noise through the window by up to 80%!

We’re going to take a deeper look at 3 solutions for window soundproofing:

1. Fantastic Frame Window Inserts
2. Quiet Quilt Barrier Blankets
3. Curtains

You can either read each section for all the details, or just a look at this handy dandy table that summarizes the potential noise reduction of each option.

Best Window Soundproofing Option: Fantastic Frame Window Inserts

The Fantastic Frame window insert is the best option for DIY soundproofing an existing window. The design innovation is all in the frame, which allows us to achieve the best possible soundproofing (and thermal window insulation) with a lightweight design. This window insert can be custom fit to just about any window and will reduce noise through the window by up to 80%. As an added perk, if you decide to install them in every window in your home, you’ll also save 40% or more on your energy bill.

We use ¼” acrylic glass in these Fantastic Frames, and a metal trim piece to magnetically attach them (and create an excellent seal) over an existing window. They’re easy to DIY install and can be removed as easily as you’d pull a similarly sized picture frame off a wall. For the highest possible STC rating (up to 51), you’ll want to create as big of an air gap as possible, but a Fantastic Frame insert will still give excellent sound reduction when installed directly next to the existing window. Wherever it’s installed, you’re going to love how much the sound is reduced. These window inserts are great for soundproofing a glass wall assembly

When you combine the peace and quiet with the energy savings, these window inserts pay for themselves in real dollars – not to mention the peace and comfort you get by blocking out all that unwanted noise.

Good Soundproofing Option: Quiet Quilt 2-Sided Barrier Blanket

If for some reason you’re unable to install window inserts, your next best option is going to be to seal up the window with a Quiet Quilt 2-Sided Sound Barrier. The Quiet Quilt barrier blanket is manufactured with grommets for easy hanging and Velcro to create a seamless connection between blankets. With absorption on both sides, the blankets can act as an additional barrier and absorber. We can make these blankets up to 48" wide and just about any length. The soundproof blanket, should completely cover the window past the edges and be adhered as closely to the window as possible. The more airtight the seal to the perimeter molding the better.

Our Quiet Quilt line is mostly used in industrial settings, but we have people use them for windows if they’d rather have a curtain than a window insert. Unlike the other curtains you may be looking at, these sound blankets weigh 50 lbs so they are dense enough to actually block noise. We also recommend these blankets for soundproofing a door.

Poor Soundproofing Option: “Soundproof” Curtains

After a sound barrier blanket, your final option is soundproof curtains. If you look on Amazon, you’d think these curtains are just all over the place! Unfortunately, most curtains advertising as soundproof curtains aren’t soundproof at all!

Most curtains being advertised as “soundproof” are acoustical products. They will absorb reverberant noise to reduce echoes in a room. And chances are they aren’t great at that either unless they have a tested NRC Rating. If you don’t see an STC Rating or an NRC Rating, you have a seller capitalizing on people’s desire for peace and quiet with a product that’s not really designed for soundproofing.

We know that many people are going to settle for curtains though, so we’ll at least help you get the ones that will work the best (reduce noise 20-30%). When choosing curtains, keep in mind that two keys to soundproofing are density and airtight installation. The heavier and thicker a curtain, the better it’s going to be at both blocking and absorbing noise. Lightweight and thin curtains will not block noise or absorb it.

You'll give the curtains the best chance at being successful by covering the entire window and then some. You’ll want to extend past the window a little bit, to reduce the amount of sound going around the curtain. Just like the Quiet Quilt barrier blanket, they need to be completely closed over the window to provide effective sound blocking. If you want sunlight, you'll have to use the Fantastic Frame Window Inserts!

If you are buying new windows and want them to be soundproof, our recommendations will change depending on whether this is an exterior window install or an interior window install. We do not sell new exterior windows, although any window you buy will be better than the highest end option offered by that manufacturer if you add a Fantastic Frame Window Insert. For interior windows, we have an excellent option – the Tru Acoustics Soundproof Window.

Exterior Window with Better Soundproofing

If you are buying new exterior windows, the choice really comes back to choosing a window that follows all three of the core features of soundproofing: (1) dense (2) limp (3) airtight. When evaluating your options, you’re looking for a measurement called an STC Rating. The STC Rating is a single number which basically tells you how much sound the window will block (higher is better).

The exact STC of a window can get complicated, but there are several things you can look for:

1. A window that seals better is going to let less sound in
2. A window that uses thicker glass will block more sound
3. A window that has 2 panes will block more sound

Laminated glass is a good upgrade as it will block more sound than tempered glass of the same thickness (about 3 dB). Damping of laminated glass is reduced by cold weather, so in double glass construction, keep the laminated pane on the side of the window closer to the interior of your home to maximize performance.

Air gaps between panes should be at least ½” wide, but more spacing is better. Every time you double the air gap, you’ll reduce the transmitted sound by another 3 decibels.

These tips are all just guideposts, as we don’t make exterior soundproof windows. We just know what makes a window soundproof and are happy to help someone who is considering their options (even if they don’t choose us!)

Interior Window with Professional Soundproof Windows

If you are buying a new interior window, we have the highest performing soundproof windows available. They are an awesome solution for recording studio windows, music practice rooms, government buildings, entertainment venues, theaters, courtrooms, gun ranges… you name an interior wall that needs soundproof windows and we’ve put a Tru Acoustics Soundproof Window in it.

Our Tru Acoustics window comes in STC 45, STC 49, and STC 56 options depending on the specs required for the room. Our windows are designed to be extremely easy to install (no need to fill frames, glass is ready to snap in), and can meet the requirements of any space. We can do custom glass (one-way), custom sizes, custom frames – just let us know what your project needs and we’ll get you set up!

You’re only as strong as your weakest link, and when it comes to room soundproofing, that is almost certainly your windows. Luckily you don’t have to resort to bricking up every window in the house to block out that unwanted noise outside your home. Depending on where you live, when your home was built, and the type of construction, you may have different windows with unique sound problems (like if you need to soundproof a skylight window in your home). If your window isn't the problem, the next step is your doors and walls. If you're curious how do you soundproof a wall, then read our article on the topic for our advice. Give us a call and we’ll help you build a plan to tackle any soundproofing problems, in the meantime check out our guide on the cost of soundproofing a window.