Benefits of Secondary Double Glazing

As well as our installations of sash, aluminium and PVCu windows we also do work fitting secondary double glazing.

It can be a cost-saving, unobtrusive addition to your home or business premises, and one that should be readily considered if you’re thinking of upgrading your windows.

Read on below to learn about some of the key benefits of secondary double glazing – and be sure to get in touch with SCI Windows if you’ve any further questions or wish to discuss your project.

GSECG Secondary Glazing

What is ‘secondary double glazing’?

Secondary double glazing is where an additional pane of glass is added to the inside of an existing window.

Conversely, traditional, non-secondary double glazing is also comprised of two panes of glass, but with an air gap in-between.

Traditional double glazing can consist of two separate windows in parallel (you physically have to open both to open the window – often found in older buildings such as country cottages), or two panes fitted close together but with a vacuum/gas-filled gap.

Secondary glazing is more specialised than double glazing. At SCI Windows we focus on the installation of secondary double glazing as it’s a quicker and less intrusive fitting process that doesn’t need a total refitting of the window unit.

Our aluminium secondary double glazing systems have all been designed to be strong, reliable, long-lasting, low-maintenance, and very discreet and unobtrusive.

Keeping the character of old windows

With secondary double glazing being able to be installed on top of existing windows, there’s no need to make a drastic overhaul to the window unit.

Should you have windows that add a lot of character to your home, secondary double glazing can be a great means of improving them while keeping the aesthetics intact.

It’s also a reversible adaptation, and can be removed if required in the future.

Secondary double glazing is therefore acceptable in many conservation areas. In summary, it’s not normally subject to building regulations or planning permission and can work in many situations.

GSECG Secondary GlazingCost saving – on installation and energy bills

Following on from the previous point – by not having to install a whole new window unit, the cost of installing secondary double glazing is comparably much cheaper.

Installation on the whole is fairly quick and easy. For starters, no external access is needed, so no scaffolding needs to be put up around your home. This keeps disturbance at a minimum, and also means it’s a cinch to install on floors that are higher up.

Moreover, there’s no need to redecorate anywhere after the job’s been done!

As well as saving on the overall cost of work carried out, you’ll be saving money thanks to the increased thermal efficiency secondary double glazing provides.

The extra layer of glass helps keep draughts at bay and stops heat escaping, meaning your home will remain warmer for longer.

SCI Windows can carry out your installation using ‘Low E’ (low emissivity) heat reflective glass. This glass reflects external heat on hot days and keep internal heat inside on cooler days.

This means you’ll be able to turn the heat down in the winter and be confident you’ll remain comfortable, while spending less!

And, should you need one for any reason, secondary double glazing will also help with achieving a domestic Energy Performance Certificate for the property.

For a rough guide to how much you could save from energy efficient windows, visit the Energy Saving Trust.

Reduce noise pollution

Adding secondary glazing to a window can vastly reduce the amount of external noise coming into your building.

Well-fitted secondary double glazing can provide much better noise insulation than sealed double glazing panes, and our specialised sound insulation windows achieve significant levels of this.

SCI Windows offers the option to use laminated acoustic glass when installing secondary double glazing to maximise the reduction in external noise pollution.

When used, this glass can help block all types of obtrusive noise, such as traffic and transport, general street noise, and industrial noise.

It’s good at stopping sounds escaping as well, and is particularly ideal for buildings that could get quite loud – such as pubs and clubs!

A bit more information for you to read before you make your decision


If you’re interested in secondary double glazing and based in Morden, Sutton, Croydon, Epsom, or slightly further afield in Surrey or South West London, call SCI Windows on 020 8648 0426 or contact us online for friendly and experienced advice from our expert team.