Soundproof Imitation Sash Windows

(Mock Sash Windows)

Combining the appearance of the sash with the functionality of modern casement, these mock sash windows deliver superior certified reductions in the noise of up to 51dB in the triple-glazed option. This is the same level achieved by installing noise reduction sash as well as acoustic secondary glazing (with 250mm cavity).

Mock Sash Window Design

Often found in Georgian and Victorian properties, sash windows are so-called for their movable ‘sashes’, often separated by glazing bars. Traditionally opened by sliding a panel up or down, our mock sash windows look just like the originals but are installed with a tilt and turn system instead.

This means you can open our mock sashes inwards 90° from the side, or tilt them from the top or bottom for effective ventilation.

How The Sash Look Is Achieved

Heritage Trim

For the authentic heritage look, all of our imitation sash windows come with Ovolo mouldings as standard.

Meeting Rails

Mimicking the meeting rail of traditional sash windows, our imitations appear to be two separate sashes.

Recessed Windows

Whilst many imitation sash windows are installed on the outer frame, our range are installed recessed behind the frame to give the perceived ‘depth’ of sash.


Superior Soundproofing

Our mock sash windows avoid the problems inherent to soundproofing traditional sash. There is no need for seals between the panes, and no internal mechanism to act like an acoustic chamber. Instead, these windows close flush, offering superior noise reduction coefficients.

“We live in Clapham North, right under the Heathrow flight path. We acquired our house; a classic Victorian Terraced house. It had the classic PVC double glazed sash windows (10 years old, average quality but not great). Noise level from plane was significant when jumbo jets would fly over, especially at 5.30AM. We opted for a triple glazed non sash option with different glass thicknesses (high performance, but looking similar), and it has completely solved the problem. We have very large bay windows, so there was a lot of window exposure for sound to come through.”

Dan Benhamou via TrustPilot

overall_rate_big 5

Finished in Style

We know that when it comes to your home only the best will do. That’s why our timber mock sash windows can be fully customised to suit your property.

Bespoke Design

Whether you want a curved frame, or a custom RAL paint job, all of our windows are bespoke and made to order.

Glazing Bars

You can choose to have just the one glazing bar, or as many as you want in keeping with your existing windows.


To complete the look, we offer a range of traditional accessories and ironmongery options for you to choose from.


It’s not just sound that windows keep out, but the cold too. The glazing has an Ug-value of up to 0.6 W/m²K, meaning that our Mock Sash Windows are A+ rated.

Product Options

Our ultra range comes with a variety of options depending upon the severity of your noise problem:

  • 39dB (68mm frame) – Calculated
  • 43dB (78mm frame) – Calculated
  • 45dB (88mm frame) – Calculated
  • 47dB (-1,-3) (88mm frame) – *Certified





Recommended For:

Moderate to high noise pollution.



Recommended For:

High levels of noise pollution.


50-51dB + 51dB Triple Glazing

Recommended For:

High to severe levels of noise pollution.



These products are recommended for those who suffer from moderate to high levels of noise pollution, or who may not be able to alter the exterior of their existing windows







Our Soundproof Mock Sash are recommended for those who suffer from high to severe levels of noise pollution and want to maintain the aesthetic of traditional sash.







Designed to look like the traditional from the outside, our mock sash windows benefit from the sturdier frame design of tilt and turn to deliver reductions of up to 51dB.

Our Soundproof Mock Sash are recommended for those who suffer from high to severe levels of noise pollution and want to maintain the aesthetic of traditional sash.

The prices displayed below do not include VAT and installation costs.


43dB Double Acoustic Glazing

Price From:



43dB Double Acoustic Glazing

Price From:



43dB Double Acoustic Glazing

Price From:



  1. What are mock sash windows?

    Mock sash windows are tilt and turn windows that are designed to look like sash. They will have the same overall look, complete with glazing bars, as traditional sash, but will have a different opening mechanism. This could either be a vertical tilt, a horizontal pull, or, as is the case with our tilt and turn windows, a combination of the two.

    Mock sash windows are a good solution for homes where the walls are not thick enough to house large sliding sash frames. They are also preferential in areas that suffer from noise pollution due to the fact that they boast far greater noise reduction values compared to the traditional design.

  2. Are mock sash windows and imitation sash windows the same thing?

    Yes. Mock sash windows are also known as imitation sash, fake sash, faux sash, dummy sash and many more names. The one thing to clarify with a company that supplies mock sash windows is what sort of opening mechanism they will employ.

  3. Can I replace my sash windows with mock sash windows?

    Yes and no. If you are not in a conservation area, you can easily replace your sash windows with mock sash windows. However, you may not be granted permission to replace sash windows in some conservation areas, even with mock sash windows designed to look like the original.

    Thankfully, we have a whole range of heritage and conservation soundproof sash windows which can be installed in these areas.

  4. Are these windows suitable for conservation areas?

    In London it is not possible to replace front-facing sash windows with our mock sash in conservation areas. However, it may be possible to get permission to change these windows in the back-facing rooms of your house. This all depends on the local authority and what elements of the building are being ‘conserved’.

    In certain conservation areas you will have to replace pre-existing frames with ones that have the same dimensions, finish and, in some cases, materials. These elements may be protected under an Article 4 direction. If you live in a conservation area it is advisable to speak to your local authority before ordering new windows.

  5. Are mock sash windows effective against noise pollution?

    Yes! Our mock sash windows have been designed specifically to combat noise intrusion, and are far more effective than traditional sash windows. They even promise superior reductions in noise than our Soundproof Sash range. This is because we can employ specialist seals and locking mechanisms that we cannot install on traditional sash designs. The design of our mock sash windows also allows us to install much heavier 51dB, 52mm deep glazing, which traditional sash cannot support.

  6. Do your mock sash windows come with a guarantee?

    All of our products come with a 10 year insurance backed guarantee from the Consumer Protection Association.

  7. What is the thickness of your mock sash windows?

    Our mock sash windows are generally thinner than traditional sash windows, and range between 68-88mm.


Unsure whether our Mock Sash Windows are for you? They might not be. Speak with one of our specialists and we will happily talk you through the products we stock.

Our guarantee: we will only ever recommend products that we think will work best for you.


Trees for Life is a conservation charity dedicated to rewilding the Scottish Highlands. They currently have 44 tree planting sites and have planted nearly two million trees to date.



All of our products come with up to a 10 Year Insurance Backed Guarantee provided by the Consumer Protection Association. So you can rest assured that your home is in safe hands.



We have been Trading Standards Approved and are proud to be enrolled on the Buy With Confidence Scheme, ensuring customers just like you have their interests protected.



Consumers can feel confident using a TrustMark registered business, as the government-endorsed scheme ensures high quality service and a range of consumer protection options.



Following awards in 2020, and 2021, The Soundproof Windows was announced as the ‘Best Acoustic Window & Door Installation Company – London’ at the SME News Awards 2022.