You are here: Home » Information Articles » Secondary Glazing Vs Double Glazing

Secondary Glazing Vs Double Glazing

Do you want to know the Value and performance of secondary Glazing vs double glazing for acoustic & thermal insulation ?

We are quiet often approached by clients who already have double glazing installed and are curious to know if installing secondary glazing will dramatically provide additional acoustic or thermal insulation.

Sound Proofing

The question we always get asked is will the secondary glazing dramatically reduce the sound coming through our windows ?

the answer is yes !

Since the two panes that form a double glazing unit are generally separated by a 16mm spacer  the air gap does not meet the recommended distance for a effective sound barrier.

Double glazing units do no not provide enough air gap for the sound waves to loose their velocity over the distance they travel, hence why they are poor insulators of sound !

To get good soundproofing performance from windows you have to create a air gap of a minimum 100mm (10-15cm), so your original window makes up the first pane, The Secondary Glazing installed to the room interior makes up the second pane/sound barrier.

As the sound waves travel and hit the external window the velocity of the sound waves are dramatically reduced, as they continue to travel through the air gap loosing velocity over distance they are eventually absorbed by the secondary glazing window glazed with a soft dampening Acoustic Laminate glass.

if your main concern is sound proofing then look no further secondary glazing will most certainly always exceed the acoustic performance of double or even triple glazed windows

Energy Efficiency

Should i install secondary Glazing or replace my windows with double glazing ?

Depending on where you live you may be restricted to the modifications you can carry out on your windows, if you live in a listed or conservation area then you must consult your local governing body to seek compliant advice and guidelines for replacing your windows.

Replacing historic or period windows can become quite costly as the design and function of what you propose has to be identical to what is already there.

Bespoke double glazing windows can cost up to three times more than secondary Glazing.

Secondary Glazing is a lot cheaper than double glazing involves a lot less work to install and doesn’t have any implications on listed building regulations.

The results you will get from the two are identical. Secondary Glazing does a great job at eliminating cold draughts and if fitted with Low E glass will also provide addition UV protection.

Low emissivity glass blocks out the harmful ultraviolet sun rays that add to the discolouring of internal furnishings and wall coverings, the uv layer also transfers heat into the room which will help maintain a warm living condition.

Our Research shows to replace a 1.2m x 1.8m wooden sash window with a aluminium double glazing sash window can cost  from £1,400 – £1,800 +VAT

A secondary Glazing sash window with Acoustic Laminated Glass from interior Glaze will cost

You £ 600 + VAT supplied and installed.

So here’s what we think, If you are shopping around to enhance the acoustic performance of your windows then secondary Glazing will give you the best results and is definitely your best option. If you are improving your windows for the thermal benefits we can honestly say that secondary glazing and double glazing are equally as effective, However if you are limited by a budget then look no further installing secondary Glazing will dramatically improve the thermal performance of your windows for a fraction of the cost of replacing them.