Home > Blog > Double Glazing vs Secondary Glazing

Double Glazing vs Secondary Glazing

Both double glazing and secondary glazing are fantastic options for insulating your home and improving your EPC rating. However, the glazing you pick will depend on the age of your home, planning permission and personal preference.

Having installed both glazing types across South East England for over 30 years, The Heritage Window Company can provide the best advice for your home.

Read on to discover whether you need double glazing or secondary glazing.

Is secondary glazing the same as double glazing?

Secondary and double glazing are not the same, but both serve the same purpose – greater thermal efficiency, better noise insulation, improved security and the potential to upgrade your EPC rating. Therefore, both glazing types have the potential to reduce your energy bills and upgrade the value of your home.

Secondary glazing and double glazing offer a significant improvement over standard windows, but each type excels in different areas, so it’s worth considering which is best for your needs.

What’s the difference between secondary glazing and double glazing?

The difference between secondary glazing and double glazing is simple:

Secondary glazing: The installation of a second, internal window – alongside your existing one – to improve insulation and soundproofing.

These window types, manufactured in-house by The Heritage Window Company, are available in many different shapes and profiles, including:

Double glazing: Two panes of glass sealed together with a gap in between, forming a single, insulated window unit.

As standard, all of The Heritage Window Company aluminium window ranges come with double glazing options, including:

The key difference: Double glazing is a completely sealed window unit, whereas secondary glazing adds an internal layer to an existing window. This is immediately noticeable from the inside of the home.

What’s better – double glazing or secondary glazing?

Double glazing is generally considered the superior option for homes, if you are looking to completely replace your existing windows. This is due to the fact that double glazing options include a fixed unit, tailor-made for your home, and usually have slightly improved insulation rates.

In contrast, secondary glazing does not replace your existing window pane, instead adding a second internal window. This makes it the preferred option for listed homes that may struggle to get planning permission in order to replace their existing window entirely.

This also makes secondary glazing a clever, bespoke solution for homeowners who either don’t want to, or are unable to, fully replace their windows.

Whether secondary glazing is as good as double glazing will depend on you and your home’s needs. Regardless of which you decide, The Heritage Window Company can add both double and secondary glazing to existing aluminium windows.

Which is better for noise reduction?

You will notice a considerable improvement in noise reduction with the addition of both secondary and double glazing.

However, secondary glazing typically has better soundproofing capabilities when compared to double glazing – this is because the second internal window creates a larger gap between window panes.

Which is better for heat insulation?

Both secondary and double glazing will ensure a considerable improvement in the heat insulation of your home.

However, high-end double glazing typically performs better than secondary glazing. This is because double-glazed units are sealed and often filled with inert gas, like argon, which significantly reduces heat transfer.

Which looks the best?

Our windows are all completely customisable, so deciding which type of window looks the best is completely up to you – but bear in mind that secondary glazing means your original window will remain visible!

Double-glazed windows appear as one unit, completely bespoke and fully customisable – perfect for curating the ideal façade.

Secondary-glazed windows appear as two units: the original external unit and the new internal unit. While you may prefer the cohesive look of one unit, secondary glazing leaves period features completely untouched, meaning this option may be preferred by those conscious of heritage features.

Please note: The Heritage Window Company was founded on the love and deep appreciation of heritage aesthetics, meaning whichever option you choose, the original look of any listed or heritage property will be fully respected.

How expensive is the installation cost?

Typically, secondary glazing will cost less to install, as it does not include the removal of an original window unit.

However, at The Heritage Window Company, we believe every job is as unique as you – which is why we don’t offer flat rates for our service.

The shape and nature of every installation is unique – especially in older properties. The Heritage Window Company will always consider your needs properly to make sure you’re only billed for the most appropriate window for your home.

The cost of installing aluminium windows in your home will depend on the size and shape of the window, how many windows are being installed, the ancillaries chosen and more.

Do I need planning permission?

For double-glazing, properties of a certain age and protected properties will need planning permission before installation – this is because double-glazed windows fully replace the existing window in the home.

However, planning permission is usually not required for secondary glazing, even if the building is grade-listed. This is because the original window will not be altered during installation.

Still can’t decide? Talk to us

If you’re still unsure which type of glazing is right for you, get in touch today.

You can do this via our enquiry form, email, phone or by visiting us in-person at one of our showrooms:

Surrey Windows Showroom
1 West Street
Dorking
Surrey
RH4 1BL

London Windows Showroom
Unit 24
Franthorne Way
Bellingham
London
SE6 3BX

Essex Windows Showroom
265 High Road
Loughton
IG10 1AH

Call today on: 0800 488 0190.

Back

Recent Blog Posts

Aluminium Window Buying Guide

Aluminium Window Maintenance