Do Double Glazed Windows Really Reduce Noise?

Traffic, barking dogs, noisy neighbours, trains and planes overhead. Outside noise is one of the most common reasons Australian homeowners start thinking about new windows. But do double glazed windows really reduce noise, and how much quieter will your home actually be?

The short answer: yes, double glazed windows reduce noise, often noticeably. Two panes of glass, an insulating gap and a well-sealed frame all work together to stop sound getting in. How much quieter your home becomes depends on the glass, the frame and the quality of the installation, which is why some double glazed windows perform far better than others.

In this guide, we explain how double glazing reduces noise, what makes the biggest difference and how to choose windows that give you a quieter home.

Why Windows Let So Much Noise In

Walls are usually thick and dense, so they’re good at blocking sound. Windows are the opposite. A single pane of glass is thin and vibrates easily, passing sound straight through to the other side.

Older windows also tend to have gaps around the sashes and frames. Sound travels through air, so even small gaps can let in a surprising amount of noise. This is why a home with old, single glazed or draughty windows can feel noisy even with the windows shut.

How Do Double Glazed Windows Reduce Noise?

Double glazed windows reduce noise in three main ways:

• Two panes of glass: sound has to pass through two separate layers of glass instead of one, losing energy each time.
• The sealed gap: the space between the panes interrupts the path of sound, helping to dampen vibrations before they reach the inner pane.
• A well-sealed frame: new frames with quality seals close off the gaps where sound sneaks in around older windows.

That last point is often overlooked. Even the best glass won’t perform well if the frame lets air (and noise) through. That’s why the frame material and installation matter just as much as the glass itself.

How Much Quieter Will Your Home Be?

Noise reduction is measured in decibels (dB), and a window’s sound insulation is usually given as an Rw rating. The higher the Rw, the better the window blocks sound.

Because decibels work on a logarithmic scale, small numbers make a big difference to what you actually hear:

Reduction in noise	What it sounds like
3 dB	Just noticeable
5 dB	Clearly noticeable
10 dB	Roughly half as loud
20 dB	Roughly a quarter as loud

Replacing old single glazed windows with quality double glazing in well-sealed frames can make a clear difference to how loud outside noise sounds inside your home. With the right glass combination, Vue’s soundproof windows and doors can achieve a sound reduction of up to 44 dB.

What Affects Double Glazing Noise Reduction?

Not all double glazed windows perform the same when it comes to noise. These are the factors that make the biggest difference.

Glass Thickness

Thicker glass is heavier and vibrates less, which makes it better at blocking sound, particularly lower-frequency noise like traffic. Using panes of different thicknesses in the same unit also helps, because each pane vibrates at a different frequency, so sound that gets through one is better blocked by the other.

Laminated Glass

Laminated glass has a thin plastic interlayer bonded between two sheets of glass. As well as holding the glass together if it breaks, the interlayer helps absorb vibrations. Acoustic laminated glass uses a special interlayer designed specifically to reduce noise, making it one of the most effective upgrades for very noisy locations.

The Gap Between the Panes

A wider gap between the panes generally improves sound insulation. However, the gap in a standard double glazed unit is designed to balance thermal and acoustic performance, so glass thickness and laminated glass usually have a bigger impact on noise than the gap alone.

Frame Material and Seals

The frame plays a big role in keeping noise out. uPVC frames have multi-chambered profiles that help insulate against both heat and sound, and quality systems use compression seals that close tightly when the window is shut. Aluminium frames conduct sound and heat more readily. Our aluminium vs uPVC windows guide explains the difference in more detail.

The window style matters too. Windows that close firmly against their seals, such as tilt and turn windows and awning or casement windows, tend to seal more tightly than sliding windows.

Installation

A poorly installed window can leave gaps around the frame that let noise straight through. Professional installation makes sure the frame is properly sealed to your home’s structure, so you get the full benefit of the glass. Our guide to window standards in Australia covers what a compliant installation involves.

What Types of Noise Does Double Glazing Block Best?

Double glazing works well on most everyday noise, but some sounds are harder to block than others.

• Voices, barking dogs and general neighbourhood noise: these mid to high-frequency sounds are usually well reduced by double glazing.
• Aircraft noise: often higher in frequency, and well suited to laminated glass.
• Traffic, trucks, trains and trams: these produce more low-frequency noise, which is harder to block. Thicker or laminated glass, combined with well-sealed frames, makes the biggest difference here.
• Deep bass and rumbling: very low-frequency noise is the most difficult to stop with any window, and can also travel through walls and floors.

If you live near a main road, train line or flight path, it’s worth talking to your window supplier about glass options designed for your specific type of noise.

Are Double Glazed Windows Soundproof?

Not completely. No window can make a home totally soundproof, and noise can also enter through walls, roofs, doors and vents. However, quality double glazed windows can significantly reduce the noise you hear inside, which is often enough to make a home feel calmer and help you sleep better.

If noise is your main concern, look for windows specifically designed for sound insulation rather than standard double glazing alone.

Acoustic Glass vs Double Glazing

Acoustic glass and double glazing aren’t really competitors. Acoustic laminated glass is a type of glass, while double glazing is a way of building the window. For the best noise reduction, they can be combined, with acoustic laminated glass used as one or both panes in a double glazed unit.

• Standard double glazing: a good all-round upgrade for comfort, energy efficiency and everyday noise.
• Double glazing with thicker or laminated glass: better suited to busy roads, train lines and flight paths.

Is Triple Glazing Better for Noise?

Triple glazing adds a third pane of glass, so you might expect it to be much quieter. In practice, a well-designed double glazed unit with thicker or laminated glass can perform just as well, or better, for noise. Triple glazing is mainly designed for thermal performance in very cold climates. Read our double vs triple glazed windows comparison to see which suits your home.

Other Benefits of Double Glazing

While noise is often the reason homeowners start looking, double glazing offers plenty of other benefits at the same time:

• Year-round comfort: helps keep heat out in summer and warmth in during winter. Learn more about how double glazing reduces heat loss.
• Lower energy bills: less work for your heating and cooling. See our guide to energy-efficient windows and doors.
• Less condensation: the inner pane stays warmer, reducing condensation on cold mornings.
• Improved security: two panes of glass and multi-point locking make windows harder to break through. Find out how secure uPVC windows are.

Comparing other options for summer heat? Read our guide on window tinting vs double glazing.

Is It Time to Replace Your Windows?

If your home has old single glazed windows, rattling sashes or gaps you can feel air coming through, replacing them is likely to make a real difference to noise levels. Other signs include condensation, sticking windows and rising energy bills. Our guide on how to know when to replace your windows covers the key signs to look out for.

Frequently Asked Questions

Does double glazing reduce noise from traffic?

Yes. Double glazing can noticeably reduce traffic noise, although low-frequency sounds like trucks and buses are harder to block than voices or general neighbourhood noise. Thicker or laminated glass and well-sealed frames give the best results for busy roads.

How much noise does double glazing reduce?

It depends on the glass, the frame and the installation. Replacing old single glazed windows with quality double glazing in well-sealed uPVC frames can make a clear difference, and with the right glass combination, Vue’s soundproof windows can achieve a sound reduction of up to 44 dB.

Are double glazed windows soundproof?

No window is completely soundproof, but double glazed windows can significantly reduce the amount of outside noise you hear indoors.

Is acoustic glass better than double glazing?

They work best together. Acoustic laminated glass can be used within a double glazed unit to improve noise reduction, particularly for homes near busy roads, train lines or flight paths.

Enjoy a Quieter Home with Vue Windows

At Vue Windows, we create custom double glazed uPVC windows using German-engineered Aluplast profiles. With multi-chambered frames and dual compression seals, our soundproof uPVC windows and doors are designed to keep noise out and comfort in.

Whether you’re dealing with a busy road, noisy neighbours or a flight path, our team can recommend the right windows and glass for your home. We offer:

• Custom uPVC windows and uPVC doors
• Professional window replacements
• Long-lasting durability with minimal maintenance
• Expert local installation across Melbourne

Ready for a quieter, more comfortable home? Contact Vue Windows today for a consultation or quote.