If your windows are draughty, noisy or let the heat straight out in winter, double glazing is usually the first fix people look at. There are two ways to get it: retrofitting a second pane of glass into your existing frames, or replacing the whole window with a new double glazed unit fitted in a new frame. Here is how they compare, what to ask before you choose, and how we do it.
Most of the replacement windows we make at our Croydon South factory today are double glazed. As an Australian owned manufacturer, we have been making aluminium windows and doors for more than 25 years, every one made to order locally and independently tested through NATA-accredited facilities, so they stand up to Melbourne’s varied, demanding climate.
What is double glazing, and what is a double glazed unit?
Double glazing puts two panes of glass in the frame with a sealed gap between them, often filled with argon gas. The gap slows heat moving in or out of the room, so your home holds its warmth in winter and stays cooler in summer. It also cuts outside noise from traffic, neighbours and weather.
A double glazed unit is the glass part of the window. It is two panes of glass joined together with a sealed gap between them, and it is made in a factory as one complete unit. We purchase our double glazed units as complete, sealed units and fit them into aluminium frames that we make to order in Croydon South.
Why people replace their windows with double glazing
- Comfort. Double glazing keeps heat out in summer and keeps warmth in during winter, so rooms hold a more even temperature and you lose the cold spots near old single glazed windows.
- Lower heating and cooling load. Your heater and air conditioner do not have to work as hard. How much you save depends on your home, the windows you replace and the glass you choose (see below).
- Less noise. Two panes and a sealed gap dampen outside noise, which matters if you live on a main road or near a train line.
- Security and safety. The glass can be chosen for added security and safety as well as comfort.
- Less condensation. The inner pane stays closer to room temperature, so you usually see less condensation on cold mornings.
- A more modern look. Replacing your windows is a chance to upgrade and modernise the look of your home, with a new frame in your choice of style and powdercoat colour.
Windows matter more to heating and cooling than most people expect. According to the Australian Government’s YourHome guide, up to 40% of a home’s heating energy can be lost, and up to 87% of its heat gained, through windows. The same guide shows that a window with half the heat transfer, such as double glazing with an argon-filled gap in a less conductive frame, can halve the heat lost through it.
Retrofit double glazing or a new double glazed window?
Retrofitting keeps your existing frame and adds or swaps the glass. Replacement removes the whole window and installs a new one with the double glazing built in. Both have their place.
| Retrofit (new glass, old frame) | Full replacement (new window) | |
|---|---|---|
| Frame | Your existing frame stays, with its age and condition | A new frame, made to measure for the opening |
| Seals and hardware | Usually stay as they are | All new: seals, rollers, locks and handles |
| Draughts | Glass improves, but gaps in a worn frame remain | New seals and a precise fit deal with draughts at the source |
| Energy rating | Depends on the old frame and the new glass together | The finished window carries a WERS rating for frame and glass together |
| Look | Keeps the existing frame style | A new look, in your choice of style and powdercoat colour |
| Best when | Frames are in good condition and you want to keep them, for example in some heritage homes | Frames are worn, warped, draughty or single glazed throughout |
If your frames are sound and you love them, retrofitting can make sense. If the frames are part of the problem, new glass alone will not fix the draughts, sticking or rattling. That is when replacing the whole window gives you more for your money.
Double glazing and aluminium frames
Aluminium is strong, so the frames can be slim while holding large double glazed panes. That means more glass, more light and a cleaner look than bulky frames. Aluminium conducts heat, so the frame system matters as well as the glass. For maximum temperature control, we can supply and install thermally broken frames for window replacement projects. A thermally broken frame has an insulating barrier between the inside and outside of the frame.
Every M.C.G window is made to order locally, independently tested through NATA-accredited facilities and carries a ratified Window Energy Rating Scheme (WERS) rating, which measures the frame and glass together. Not every supplier has WERS-rated windows, so when you compare quotes, ask for the WERS rating of the exact window you are being offered. It is the fairest way to compare one double glazed window with another. Our WERS guide explains how the ratings work.
Choosing the glass
Not all double glazing is the same. The glass can be chosen for what matters most in each room: keeping heat in, keeping summer sun out, reducing noise, privacy, or added safety and security. We have a wide range of glass available to suit your energy, privacy, noise and compliance requirements. Get in touch and let us know what you need, and we will support you in choosing the right glass for each room.
How double glazed window replacement works with M.C.G
- Free consultation and quote. You submit an enquiry and our team contacts you directly. A consultant visits your home, takes sizes and talks you through styles, glass and colours. We then send you a written quote.
- Check measure. Once you go ahead, a service technician measures every opening precisely.
- Made to order in Croydon South. Your double glazed windows are made at our factory to your exact measurements, approximately 5 weeks from the check measure.
- Installation. Our own team removes the old windows and any rubbish, installs the new ones and fits new architraves and external trims if required.* Installation takes from 1 day up to 2 weeks, depending on the number of windows, access and project requirements.
* Painting of the reveals and new architraves is not included and is arranged by the homeowner.
Double glazed window replacement is not disruptive. Most homes can be lived in while the work is done. Your replacement windows carry a 7-year warranty, with a 12-month warranty on moving parts. Read the full step-by-step in our window replacement guide.
What does double glazed window replacement cost?
The price depends on the size and style of each window, the glass you choose, the frame system and how easy the openings are to get to. Double glazing costs more than single glazing up front. The return comes in comfort, lower heating and cooling load and less noise for as long as you live there. The only accurate figure is a quote for your windows, and the consultation and quote are free.
Do I need a permit?
Replacing a window with one the same size usually does not need a building permit. Requirements vary from property to property, and checking what applies to your home is the homeowner’s responsibility. If you are changing the size of an opening, or your home is under a heritage overlay, please contact your local council for more information.
Frequently asked questions
Is it better to retrofit double glazing or replace the window?
It depends on your frames. If they are in good condition and you want to keep them, retrofitting can work. If they are worn, warped or draughty, replacing the whole window gives you new frames, seals and hardware as well as the double glazing, and the finished window carries its own WERS rating.
What is a double glazed unit?
A double glazed unit is two panes of glass joined together with a sealed gap between them, made in a factory as one complete unit. We purchase complete sealed units and fit them into aluminium frames that we make to order in Croydon South.
Do you make double glazed aluminium windows?
Yes. Most of the replacement windows we make today are double glazed. Every window is made to order at our Croydon South factory and installed by our own team.
Can you replace single glazed windows with double glazed ones?
Yes. We remove the old single glazed window and install a new double glazed aluminium window made to fit the opening.
Does double glazing reduce noise?
Yes. Two panes of glass with a sealed gap between them dampen outside noise, which helps if you live on a main road or near a train line. We have a wide range of glass available, so tell us what you need and we will support you.
Is double glazed window replacement disruptive?
No. Most homes can be lived in while the work is done. Installation takes from 1 day up to 2 weeks, depending on the number of windows, access and project requirements.
How long does double glazed window replacement take?
Our windows are made to order in approximately 5 weeks from the check measure, and installation takes from 1 day up to 2 weeks. From your first visit to installation, six to eight weeks is typical. We confirm the timing in your quote.
Book a free consultation
Thinking about double glazed windows for your home? Book a free consultation and quote. When you submit an enquiry, our team will contact you directly to arrange a time for a consultant to visit your home anywhere across Melbourne or the Mornington Peninsula. You can also call us on 1300 766 349. Find out more about our aluminium window replacement service.