Double Glazing Windows & Doors FAQs

Double glazed windows provide numerous benefits including:-

1. They better insulate your home reducing heat loss during winter & heat gain during summer and can significantly reuce your heating & cooling costs as a result
2. They provide significant soundproofing benefits thus improving your quality of life & particularly in bedrooms can help you get a good nights sleep, if for example, you live near major roads

If you have existing windows, secondary double glazing is cheaper than traditional double glazing, gives better thermal insulation & soundproofing benefits & also, because we completely seal around the new interior window, they also provide the additional benefit of completely eliminating drafts, dust, bugs & insects from entering your home.

Our secondary double glazed windows are typically 30% or more less than traditional double glazed windows as we don’t completely replace the existing window but rather add a sealed unit inside your existing window.

We charge as little as $500 m² for double glazed windows manufacture, supply & installation (includes GST) in Melbourne … but please not that prices fluctuate wildly with exchange rates & materials costs, so please only use this as a guide.

A double glazed window is simply a window with multiple panes of glass with an air gap in between the panes of glass to aid noise reduction or soundproofing & reduced thermal transfer (ie. Less heat out in winter & heat in in summer).

There are two approaches to double glazing windows. The more expensive option is to completely replace the existing window with a new window with two panes of glass. Then there’s our much cheaper & less disruptive approach, where we simply fit a new window on the inside of your existing window.

Double glazing is simply having two panes of glass in your door or window to reduce thermal transfer & noise.

You can either have traditional double glazing where your existing windows are completely replaced by dual pane windows or doors, or our much cheaper and better soundproofing option where we install a new door or window inside your existing windows.

The best and cheapest option for thermal & noise insulation for existing windows is with secondary double glazing. See our Save Energy Costs page for more information.

We install a new window inside your existing windows. The large air gap provides excellent soundproofing & thermal transfer or insulation benefits and is typically 30% or more cheaper than replacing your windows entirely.

Air is a much better insulator than glass, meaning it transfers het much less efficiently.

When you have double glazed windows, there is the addition of an insulating air gap between the two panes of glass.

The larger air gap with secondary double glazing versus traditional double glazing means secondary double glazing provides better thermal transfer or insulation  & soundproofing benefits and, at the same time, is typically 30% or more cheaper than replacing your windows entirely as is required with traditional double glazing.

In a word, yes.

Double glazed windows both reduce heat loss during winter & reduce heat gain during summer. Double glazed windows provide good thermal insulation due to the air gap between the two panes of glass.

But … the best and cheapest option for thermal & noise insulation for existing windows is with secondary double glazing. See our Save Energy Costs page for more information.

We install a new window inside your existing windows. This gives you a larger air gap which provides superior soundproofing & thermal transfer or insulation benefits and is typically 30% or more cheaper than replacing your windows entirely which is what happens when you install traditional double glazing.

As we also completely seal around the new windows, we eliminate gaps around the frame where heat can enter or escape our house providing further thermal insulation benefits particularly as compared to traditional double glazing.

Air is a much better insulator than glass, meaning it transfers heat much less efficiently.  Glass, while relatively poor at conducting heat compared to metals, still conducts heat better than air. 

Double glazed windows & doors both reduce heat loss during winter & reduce heat gain during summer primarily due to the insulating air gap between the two panes of glass.

And with secondary double glazing, because we also completely seal around the new windows, we eliminate gaps around the window or door frame where heat can enter or escape our house providing further thermal insulation benefits particularly as compared to traditional double glazing.

Both traditional double glazing & secondary double glazing provide an insulating gap of air between two panes of glass, which will help reduce or stop condensation forming on your glass windows &/or doors.

However, secondary double glazing is a more cost effective solution (as we don’t completely replace your existing windows) & also, in the case where the seal deteriorates or breaks & condensation does form, our secondary double glazed windows &/or doors will allow you access to the interior gap to allow you to clean any water residue stains which may occur.

If you have traditional double glazing & have this problem, you can buy a kit online, which enables you to drill a small hole in the glass top & bottom, blow air into the holes to ventilate the moisture out & then reseal the holes.

This problem does not occur with our secondary double glazing. This is just another reason why retrofitting secondary double glazing to existing windows is the best option for double glazing existing windows & doors.

It certainly is possible, but most DIY or Do It Yourself Double glazing solutions don’t allow you access to your existing windows to open and close them. This can be a limitation to your lifestyle.

Absolutely you can add double glazing to existing windows. That is our speciality. We retrofit or secondary glaze your existing window with a new window on the inside of your house.

Retrofitting secondary glazing to existing windows provides better soundproofing & thermal insulation & eliminates drafts. And, because you’re only fitting one new pane of glass, it is usually more than 30% cheaper than completely replacing windows as is the case with traditional double glazing.

Sometimes old windows have been painted shut or with time, the seal around the window & frame have become less than satisfactory & allow draughts, dust, insects in, whilst allowing heat to escape far too easily.

Or, you may have leadlight windows or older style multi-pane windows that you really want to retain rather than completely replace to get the benefits of double glazing.

We can retrofit or secondary glaze your existing old windows (including leadlight windows & multi-pane windows) by installing new windows on the inside of your existing windows.

Retrofitting secondary glazing to existing old windows provides soundproofing, thermal insulation & completely seals your window which eliminates drafts.

And, because you’re only fitting one new pane of glass with secondary double glazing, it is usually more than 30% cheaper than completely replacing windows as is the case with traditional double glazing.

Absolutely. We can retrofit or secondary glaze your existing wooden frame windows (including leadlight windows & multi-pane windows) by installing new windows on the inside of your existing windows.

As an example, check out this video which shows us installing or retrofitting secondary double glazing over an existing wooden framed leadlight window. Seeing is believing!

And, because we’re only fitting one new pane of glass with secondary double glazing, it is usually more than 30% cheaper than completely replacing windows as is the case with traditional double glazing.

We can retrofit double glazing to existing sash windows. We retrofit or secondary glaze your existing sash window with a new vertical sliding window on the inside of your house.

Retrofitting secondary glazing to existing sash windows provides better soundproofing & thermal insulation & eliminates drafts. And, because you’re only fitting one new pane of glass, it is usually more than 30% cheaper than completely replacing windows as is the case with traditional double glazing.

We can add double glazing bay windows. We retrofit or secondary glaze your existing bay window with a new window installed on the inside of your house.

Retrofitting secondary glazing to existing bay windows provides better soundproofing & thermal insulation & eliminates drafts as compared to traditional double glazing. And, because you’re only fitting one new pane of glass, it is usually more than 30% cheaper than completely replacing windows as is the case with traditional double glazing.

We can double glaze existing leadlight windows. We retrofit or secondary glaze your existing stained glass leadlight window with a new vertical slider window or hinged panel window on the inside of your house.

Retrofitting secondary glazing to existing windows provides better soundproofing & thermal insulation & eliminates drafts as compared to traditional double glazing. And, because you’re only fitting one new pane of glass, it is usually more than 30% cheaper than completely replacing windows as is the case with traditional double glazing.

We can double glaze existing glass French doors. We retrofit or secondary glaze your existing French doors by installing a new hinged glass doors on the inside of your existing French Doors in your house.

Retrofitting secondary glazing to existing glass doors provides better soundproofing & thermal insulation & eliminates drafts as compared to traditional double glazing. And, because you’re only fitting one new pane of glass, it is usually more than 30% cheaper than completely replacing existing French doors as is the case with traditional double glazing.

Check out the Secondary Double Glazed French Doors page for more information including a video of an actual installation or the French Door Picture Gallery page for an idea of how they look.

Absolutely you can retrofit double glazing to existing windows. That is our speciality. We retrofit or secondary glaze your existing window with a new window on the inside of your house.

Retrofitting secondary glazing to existing windows provides better soundproofing & thermal insulation & eliminates drafts. And, because you’re only fitting one new pane of glass, it is usually more than 30% cheaper than completely replacing windows as is the case with traditional double glazing.