Sound Proofing Period Windows & Doors

Sound Proofing Period Windows & Doors

Can wooden sash windows be sound proofed?

Acoustic glass and perimeter seals will improve noise insulation but the design of sash windows  prevents perfect sound proofing.

Sash Window Specialist accept that period windows will never be totally sound proof; they were not designed that way. Although we can’t offer a perfect solution we do know how great improvements can be made.

soundproofing & sound sealing period windows & Doors | Sash Window Specialist Perth-

Noise leaking into our homes is an ever increasing annoyance. Sash Window Specialist offer advanced solutions to help control noise pollution entering from wooden period windows & doors. 

The first step towards improved sound insulation from timber sash windows and doors is to ensure that effective draught seals are fitted and any air gaps around the frames are sealed. No matter how well the glazing reduces noise, if there are air gaps then noise will penetrate your home. Draught seals reduce air leakage from outside so they also reduce air-borne noise & dust.

Many of our customers have commented on how well our Standard Draught Seal & Overhaul service has reduced noise. But in many urban environments this solution is not adequate and upgrading the glass should be the next consideration.

A thicker glass will improve acoustic insulation and soundproofing.  We offer a wide range of glazing options from all the leading glass suppliers. 

Sound proofing for noise reduction is a very complex problem and no matter how good a particular product measures in laboratory tests those results are not always reflected in real world situations. Glazing manufacturers offer their test results as guidance only.


Acoustic Properties Of Glass

Obscured / patterned sash glass

Float Glass – the standard glass that has been fitted for many years is often only 2 or 3mm thick. Simply increasing the thickness will reduce the amount of noise. 

When a wide range of decorative glass is required, such as bathrooms, this is the best solution. Patterned glass is available in a range of thicknesses dependent on the design.

Laminated window Glass.Standard Laminated Glass – manufactured by bonding multiple panes of glass together with a thin inter-lay film sandwiched between the glass layers. Laminated glass has many benefits including greatly reduced ultra violet (UV) light ingress, Grade A safety glass, improved security as well as improved noise reduction. Improvements of up to 24% can be achieved over existing 3mm float glazing.  In our experience standard laminated glass often offers a cost effective solution. A limited range of patterns are available.


Accoustic Laminate Window Glass.Smart’ or Acoustic Glass – laminated glass that incorporates a ‘smart’ interlayer. The interlayer is designed to dampen noise and may reduce noise by up to 40% in comparison to similar thickness float glass. Acoustic glass is more expensive than standard laminated glass.

double glazed unit for sash window.
Double Glazing – standard double glazing with 2 glasses of the same thickness offers little sound insulation. However when laminated glass is incorporated into a sealed double glazed unit the benefits can be significant.  This is not only a great solution for reducing noise but the thermal improvements are a welcome benefit to every home.

Before replacing glass consider:

  • In vertically sliding sash windows the weight of the glass must be offset by the balance mechanism. For every increase in the thickness of glass there is a corresponding increase in the cost to re-balance the mechanism.
  • It is usually possible to double the thickness of single glazing without modification to the frame e.g. existing 3mm glass can be replaced with 6.5mm.
  • For glass thicker than 6.5mm the frame will usually need to be altered. Unless noise intrusion is a very substantial problem the costs incurred to install thicker glass are seldom cost effective. Replacement double glazed laminated sashes are recommended for the best noise reduction.
  • Replacing old glass with new can change the colour of the light entering your home and alter how light reflects from the glass.

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Noisy Period Homes & Offices

Whilst windows are often targeted as the major cause of noise intrusion they are not the sole culprits. Air vents, walls, floors, ceilings and chimneys are all areas that can be acoustically improved. These areas should all be given equal consideration when a significant improvement in noise reduction is expected.

Soft furnishings absorb sound very well. Current trends in decor such as removing carpets in favour of polished floor boards or replacing heavy drapes with blinds adds to the problem. Simply incorporating more soft furnishings will improve problems associated with noise.

Sealing Period Windows Shut Is An Acceptable Solution In Some Particularly Noisy Environments

soundproofing & sound sealing period windows & Doors | acoustic glass | Sash Window Specialist Perth-
Box Sash Window Weight Cavity Insulated

At Sash Window Specialist we do not normally like to seal windows shut but there are times when this must be considered as the best solution.  Properties opening onto busy roads and thoroughfares with no front garden would be prime candidates.  The trade off for lost functionality is the best sound-proofing possible in a period window, without installing a secondary glazing system.  The sound reduction achieved with this solution can be quite substantial.

  • The thickest acoustic glass possible is fitted to the existing sash frames. 
  • All sliding open functionality is lost as the sashes become fixed shut and sealed in place.
  • Gaps where the frame meets the building structure are sealed off.
  • The weight cavity inside the box window is filled with insulation to dampen noise.  


At Sash Window Specialist we understand the charm of traditional wooden windows which is why all of our work is designed to be as sympathetic as possible.

Our draught seals are machined into the timber components to become an integral, practically invisible part of the window. Our Draught Seal & Restore Service is ideal for conservation areas and listed buildings.

Heritage aproved draught seals

We have been using the same top quality British made draught seals for over 20 years.  Brush draught seals are the best option for long life in a sliding sash window.

Windows are a favourite entry point for burglars

Various catches effectively bring the sashes into a locked position, however the screws holding these in place are small and these catches should not be considered an effective security measure. We have a range of sash window security options available.  We also supply a wide range of sash window furniture, available in variety of finishes.

Security Stops For Timber Sash Windows. Double Hung.