Our system sits in a different performance category for five main reasons:

Many lower-cost systems are marketed with impressive figures such as 49–52dB. In many cases, that figure reflects a combined laboratory test using the secondary unit together with an existing primary window and a large air gap.

Our quoted 49dB relates to the performance of our secondary system itself, rather than a lightweight pane relying on a favourable combined laboratory arrangement to achieve a stronger-looking figure. When paired with the existing primary window and air cavity, the overall acoustic performance can increase further and, in favourable conditions, may approach the 60dB range, depending on the site conditions.

Most standard sliding systems rely on brush seals. They allow the unit to move, but they are not truly airtight.

Our timber acoustic system uses dual compression seals and multi-point locking, so the unit closes under pressure against the frame. This creates a far tighter acoustic seal and is one of the key reasons it performs so much better in real homes.

A single 6.8mm laminated pane is limited in what it can do, especially against traffic rumble and lower-frequency noise.

Our system uses a sealed, heavy acoustic double-glazed unit with an asymmetric build-up (for example, 8.8mm / 20 / 10.8mm or 12.8mm / 20 / 10.8mm), specifically designed to tackle a broader range of frequencies, including the deeper, more difficult parts of road noise.

A standard single secondary pane offers only modest thermal improvement.

Our sealed acoustic unit also delivers a far stronger thermal result, helping the room feel less cold, less draughty, and more stable in temperature. For many clients, this becomes a second major benefit after the noise reduction.

Even a good secondary system can underperform if the perimeter installation is weak.

We do not simply fit the frame and foam the gaps. We use an installation approach based on acoustic sealing principles, with layered materials designed to reduce leakage and flanking paths around the frame. That detail matters enormously to final performance.

One of the biggest areas of confusion in the secondary glazing market is how acoustic results are presented.

A lower-cost system may be marketed using a headline figure achieved under a combined test condition: a secondary pane positioned behind another window, with a generous cavity, inside a controlled laboratory wall. That can produce a strong-looking result on paper, but it does not necessarily reflect the performance of the secondary unit on its own, nor what will be achieved in a normal domestic installation.

That matters because the size of the air gap in a home is often much smaller than in the test arrangement.

Our approach is more transparent: we focus on the performance of the secondary system itself as the core benchmark. Any benefit from the existing window and cavity is then an additional gain, rather than something used to inflate the headline claim.

For clients, the important point is this: two products can be marketed with similar dB figures while delivering very different real-world outcomes.

Acoustics is not linear. Small differences on paper can translate into a very noticeable difference in day-to-day comfort.

That is especially true when the noise source is not just general outside activity, but traffic, buses, engine vibration, road rumble, and other low-frequency energy.

These are the sounds that many lightweight systems struggle with.

Our system is designed around:

• higher mass
• asymmetric glass thicknesses
• airtight compression sealing
• a more robust frame and closing mechanism

Together, these elements do far more to control the type of sound most clients actually complain about: not just sharp, high-frequency noise, but the heavier low-end disturbance that makes a room feel unsettled.

In simple terms, the result is not just less noise, but a room that feels more removed from the street outside.

This is one of the most important differences, and one of the least understood.

A sliding system must have movement clearance. That means it cannot compress tightly against the frame in the same way a properly sealed compression system can. To accommodate movement, it typically relies on brush seals.

Brush seals can be perfectly acceptable for basic secondary glazing, but they are not the best solution where maximum acoustic control is the priority. Sound travels through air, and even small leakage paths can undermine performance.
Our system is designed to close under pressure.

When the handle is engaged, the sash is pulled tightly into the frame using compression seals and multi-point locking. This creates a much tighter perimeter seal and greatly reduces the leakage paths that commonly let sound bypass the glass.

This is one of the main reasons why two systems with apparently similar glass specifications can behave very differently once installed.

A standard aluminium secondary slider often uses a single laminated pane, commonly around 6.8mm.

That may offer some improvement, but it remains a relatively lightweight barrier.

Our system uses a much heavier acoustic insulated unit, typically with an asymmetric make-up such as:

• 8.8mm acoustic laminated
• 20mm cavity
• 10.8mm acoustic laminated

This gives several important advantages:

• more overall mass
• better damping of vibration
• improved behaviour across a wider frequency range
• much better performance against harder-to-control traffic noise

The asymmetric arrangement is also important. Using different pane thicknesses helps reduce coincidence effects and improves acoustic control across more of the spectrum, rather than leaving a single weak point in performance.

In practice, that means better control not just of obvious street noise, but of the deeper “presence” of traffic that many clients find most tiring.

Most people initially enquire because of noise, but once installed, many also notice a major improvement in how the room feels thermally.

A basic single secondary pane can help a little, but it does not compare with a sealed double-glazed acoustic unit.

Because our system incorporates a properly insulated unit, it delivers a much stronger thermal performance. That means:

• a warmer internal glass surface
• less cold radiation near the window
• fewer draught-like sensations
• better overall heat retention

So while the decision may begin as an acoustic one, the day-to-day benefit is often both quiet and comforting.

Even the best-designed acoustic window can underperform if the installation around it is poor.

The perimeter gap between the new frame and the surrounding structure is a common weak point. If that area is treated as a simple filling exercise rather than an acoustic junction, sound can leak around the system instead of through it.

That is why our installation approach goes beyond standard fitting.

We use a layered acoustic sealing method designed to reduce leakage and flanking transmission, including:

• acoustic membranes
• acoustic tapes
  
• specialist low-expansion foams
• high-mass acoustic sealants
• careful perimeter detailing throughout

This is not just about neat finishing. It is about protecting the performance you are paying for.

A lower-cost system may still be well intentioned, but if the perimeter treatment is basic, the final result can fall well short of expectations.

But if your property suffers from:

• heavy road traffic
• buses or HGVs
• persistent low-frequency rumble
• a room that feels both noisy and draughty
• a desire for a genuine step-change rather than a minor improvement

then a higher-performance compression-sealed acoustic system is usually the more appropriate solution.

That is why our system costs more.

It is not simply a different frame material or a premium finish. It is a different level of engineering, a different installation standard, and a different expected outcome.

Our system is for clients whose priority is not simply to spend less, but to solve the problem properly.

If you are comparing quotes, the real question is not:

“Which one is cheaper?”

It is:

“Which one is actually designed to deliver the level of quiet, comfort, and performance I want to live with for years to come?”