If you’re renovating or building, awning windows are one of the more practical styles to consider — and pairing them with double glazing can make a noticeable difference to comfort and energy bills. This guide explains what double glazed awning windows are, their real benefits and trade-offs, what they cost in Australia, and how to choose the right frame and glass for your home and climate.
Quick answer
Double glazed awning windows are top-hinged windows that open outward from the bottom, fitted with two panes of glass sealed around a gap. The design seals tightly when closed, lets you keep a window open during light rain, and insulates far better than single glazing. They suit kitchens, bathrooms and spots high on a wall. Whether the double-glazing upgrade pays off depends on your climate, your current windows and your budget — it delivers the most benefit in homes with cold winters or hot summers and old, draughty windows.
What are awning windows?
Awning windows are hinged at the top and open outward from the bottom, usually with a crank or winder. Because the glass tilts out and down like a small awning, rain tends to run off rather than straight in, so you can often leave them open a little during a light shower.
Their main strengths are a tight seal, good control over airflow, and the fact that they open outward — so they don’t take up space inside or clash with blinds and curtains. One trade-off is that, opened by a short winder, an awning window has a smaller maximum opening than a side-hinged casement or a louvre window.
What does “double glazed” mean?
Double glazing uses two panes of glass sealed with a gap between them, forming an insulated glass unit (IGU). The gap — often filled with still air or an inert gas such as argon — slows the flow of heat through the window. Many units also use a low-emissivity (low-e) coating, a very thin layer on the glass that reflects heat while still letting light through.
You’ll sometimes see units described by thickness, such as around 28mm overall, with thicker units (around 40mm) able to house triple glazing. What matters more than the number is the U-value: a measure of how quickly heat passes through the whole window. A lower U-value means better insulation.
Benefits of double glazed awning windows
Better insulation and lower energy bills
Windows are a weak point for heat flow. According to the Australian Government’s YourHome guide to glazing, a home can lose up to 40% of its heating energy and gain up to 87% of its heat through windows. Roughly halving a window’s U-value — which double glazing can do compared with standard single glazing — can roughly halve that conductive heat loss. These are indicative figures; your actual savings depend on climate, orientation, shading and how your home is built.
Ventilation, even in light rain
Because the glass angles outward and down, awning windows can stay open during a light shower while keeping most rain out — useful above a kitchen sink, in a bathroom, or high on a wall for airflow.
A tighter seal against draughts
Awning and casement windows seal by compression when the sash closes against the frame, which controls air leakage better than sliding windows, whose seals wear over time. Fewer draughts means more consistent indoor temperatures.
More security options
The winder handle sits on the inside, so an awning window can’t simply be pushed open from outside. Many can be fitted with locks and opening restrictors, which also help meet safety requirements (see “Choosing and installing” below).
Quieter rooms and less condensation
Sealed double glazing reduces medium-to-high-frequency noise such as voices; for low-frequency traffic or aircraft noise, thicker or laminated glass helps more. Double glazing also keeps the inner pane closer to room temperature, which reduces condensation and the mould it can cause.
The trade-offs to weigh
Double glazed awning windows aren’t the right answer in every situation. Worth considering:
- Higher upfront cost than single glazing (see costs below).
- Smaller opening area than casement or louvre windows, so they’re less suited to spots where you want maximum airflow.
- Outward swing, which can collect dirt on the outside and may be awkward to clean or to place beside walkways.
- Winders and hinges need occasional maintenance to keep operating smoothly.
- Climate matters. In warm, cooling-dominated areas such as Brisbane or Darwin, the payback period for double glazing can be longer, and controlling solar heat (shading and low-SHGC glass) often matters more than insulation alone.
uPVC, aluminium or timber frames?
The frame affects insulation, maintenance and price. A common myth is that uPVC is always the cheapest — in Australia, aluminium is usually the lowest upfront cost, while uPVC is valued more for its insulation and low maintenance than for being the cheapest option.
| Frame | Insulation | Maintenance | Typical upfront cost |
|---|---|---|---|
| Aluminium | Lower (conducts heat unless “thermally broken”) | Low | Usually lowest |
| uPVC | Good (similar to timber), excellent seals | Low; limited colour range | Mid-range |
| Timber | Good natural insulator | Higher (needs upkeep) | Premium |
| Composite / thermally broken aluminium | High | Low | Higher |
As a guide, indicative whole-window U-values (from the Window Energy Rating Scheme, not for compliance use): a single-glazed aluminium window is around 6.9; single-glazed timber or uPVC about 5.5; double-glazed aluminium about 4.2; and double-glazed timber or uPVC about 3.0. High-performance units with low-e glass and argon can reach around 1.2 or lower.
How much do double glazed awning windows cost in Australia?
Costs vary widely with window size, frame, glass type and site access, so treat these as indicative ranges from trade and consumer sources rather than fixed prices:
- Broadly, double glazing is often quoted at around $300–$1,500 per square metre.
- Per window installed, uPVC units are commonly around $800–$1,500 and aluminium around $1,200–$2,000.
- Double glazing typically costs two to three times a comparable single-glazed window.
Retrofitting can be cheaper than full replacement — secondary glazing adds a clear acrylic or glass panel to an existing window to create an insulating air gap, improving insulation and noise control, though not quite to the level of a purpose-built IGU.
Awning vs casement vs sliding windows
| Window type | How it opens | Best for | Watch-outs |
|---|---|---|---|
| Awning | Top-hinged, outward from bottom | Rainy-weather airflow, high or small openings, tight seal | Smaller opening area |
| Casement | Side-hinged, swings out | Maximum ventilation, larger openings | Can’t easily stay open in rain |
| Sliding | Slides horizontally | Easy operation, large glass area | Seals wear, so more air leakage over time |
Choosing and installing
A few checks help you get a window that performs as promised:
- Compare the WERS rating. The Window Energy Rating Scheme rates windows for heating and cooling using U-value and solar heat gain, so you can compare like with like.
- Match glass to climate and orientation. North-facing windows, shading and the right low-e glass all affect comfort — not just whether the window is double glazed.
- Use a qualified installer. Windows must meet Australian Standard AS 2047 for structural performance and water resistance; poor installation can undo good glazing.
- Factor in safety rules. In new homes and apartments, windows more than 2m above the ground generally need locks that limit the opening (commonly to 125mm) or reinforced screens to protect young children. Opening restrictors on awning windows can help meet this. For wider household security, see these practical steps to make your home safer.
If you’re upgrading other openings too, our guide to the benefits of double glazed entrance doors covers the same thinking for doors. You’ll find more projects in The Care Diary’s home improvement guides.
Final thoughts
Double glazed awning windows combine practical ventilation with strong insulation and a tight seal, which is why they’re a popular choice in Australian homes. The upgrade isn’t automatic, though: weigh your climate, your existing windows and your budget, compare WERS ratings rather than marketing claims, and use a qualified installer. Done well, it’s an investment in comfort and lower running costs for years to come.
