Key Takeaways
- The main types of window glass for homes are float (annealed), toughened, laminated, Low-E, tinted or reflective, and obscure glass, and they can be combined in one unit.
- Safety glass, meaning toughened or laminated, is required in higher-risk locations such as doors and low-level glazing under AS 1288.
- Low-E coatings and double glazing cut heat transfer, while laminated glass is the best choice for reducing noise.
- Choosing glass is a trade-off between safety, comfort, privacy, noise and cost, so match the type to each room.
The Main Types of Window Glass at a Glance
Glass is not a single product. Each type is made differently and solves a different problem, from safety to energy savings to privacy.
This table summarises the glass types most homeowners will come across when choosing windows.
| Glass type | Best for | Main benefit | Consider |
|---|---|---|---|
| Float (annealed) | Standard windows away from risk areas | Clear and economical | Breaks into sharp pieces |
| Toughened | Doors, sidelights, low-level glass | Strong, breaks into small pieces | Cannot be cut after toughening |
| Laminated | Security, noise, safety | Layers hold together if broken | Costs more than float glass |
| Low-E | Energy efficiency | Reflects heat, reduces transfer | Slight tint in some coatings |
| Tinted or reflective | Sun-exposed rooms | Reduces glare and solar gain | Reduces natural light |
| Obscure or frosted | Bathrooms, entries | Privacy with light | Limited view |
Float Glass
Float glass, also called annealed glass, is the standard clear glass used in most basic windows. It is smooth, clear and inexpensive, which is why it is the starting point for other glass types.
Float glass is not a safety product on its own. When it breaks, it forms large, sharp shards, so it is not suitable for doors or low-level glazing.
Toughened Safety Glass
Toughened glass is float glass that has been heated and rapidly cooled. This process makes it several times stronger than annealed glass of the same thickness.
When toughened glass breaks, it crumbles into small pieces that are less likely to cause serious injury. Australian Standard AS 1288 sets out where safety glass is required.
- Doors and sidelights: glass in or beside a door is at high risk of human impact.
- Low-level windows: glass close to the floor needs safety rated glazing.
- Bathrooms: glass near showers and baths is commonly specified as safety glass.
- Large panes: bigger sheets carry more risk, so they often need toughened or laminated glass.
Laminated Glass
Laminated glass has two or more layers of glass bonded to a clear plastic interlayer. If the glass cracks, the interlayer holds the pieces in place rather than letting them fall.
That construction makes laminated glass a good choice for security, safety and sound control.
- Security: the glass is harder to break through quickly.
- Noise reduction: the interlayer dampens sound, which helps near busy roads or flight paths.
- UV filtering: laminated glass blocks much of the ultraviolet light that fades furniture.
- Safety: broken glass stays together in the frame.
Acoustic laminated glass typically adds 20 to 35% to the cost of a window. If noise is your main concern, our page on soundproof windows explains your options.
Low-E Glass
Low-E, short for low emissivity, glass has a very thin coating that reflects heat. In winter it helps keep warmth inside the room, and in summer it helps limit heat coming in.
- Best in double glazing: Low-E works most effectively as part of a sealed double glazed unit.
- Cost: it typically adds 10 to 20% to the price of a window.
- Payback: many households recover the cost through lower heating and cooling use.
Our guide to energy efficient glass shows how coatings, gas fills and spacers combine.
Double and Triple Glazed Units
A double glazed unit is two panes of glass separated by a sealed gap. That gap is filled with air or an inert gas to slow the transfer of heat.
At Ultimate Windows, argon gas is standard in our double glazed units at no extra cost. Our uPVC windows are up to 4.5 times more energy efficient than standard aluminium-framed windows, and the glass build-up is a large part of that.
- Double glazing: two panes with a sealed 16mm space between them, suited to most homes.
- Triple glazing: three panes and two gaps, used where very high performance or noise control is needed.
- Warm edge spacers: non-metal spacers reduce heat loss and condensation at the glass perimeter.
To weigh up the extra pane, read our comparison of double glazing compared with triple glazing.
Tinted, Reflective and Obscure Glass
Some glass types are chosen for comfort and privacy rather than strength. They can be added to float, toughened or laminated glass.
- Tinted glass: coloured through the thickness of the glass to reduce glare and absorb some heat.
- Reflective glass: a surface coating that reflects sunlight and gives daytime privacy.
- Obscure or frosted glass: patterned or etched so light passes through but views do not.
- Opaque panels: solid panels used in doors where no view is wanted.
Glass Thickness and Other Details to Check
Thickness and build-up affect strength, weight and sound control. Your supplier should list these details on every quote so you can compare properly.
- Thickness: larger panes generally need thicker glass to stay rigid and meet AS 1288.
- Mixed thicknesses: using different thicknesses in one unit helps break up sound frequencies.
- Gas fill: argon improves insulation compared with plain air in the gap.
- Spacer type: warm edge spacers perform better than metal ones.
- Edge seal quality: a failed seal lets moisture into the unit and cannot be repaired.
- Guarantee: our 12-year guarantee is seven years longer than the five the AWA recommends.
How to Choose the Right Glass for Each Room
The best glass is rarely the same throughout a house. Work through each room and ask what problem the glass needs to solve.
- Identify where safety glass is required, such as doors, sidelights and low windows.
- Choose Low-E double glazing for living areas and bedrooms to improve comfort.
- Use laminated glass facing roads, flight paths or shared walls to cut noise.
- Pick obscure glass for bathrooms and entry areas where privacy matters.
- Consider tint or shading on west-facing glass that gets strong afternoon sun.
- Ask for a fixed-price quote that lists the glass specification for every window.
Frequently Asked Questions
What is the strongest type of window glass?
Toughened glass is several times stronger than ordinary float glass of the same thickness, and laminated glass resists break-through because its interlayer holds the pieces together. For the highest security, a laminated build-up is generally preferred, sometimes using toughened glass layers.
What is the difference between toughened and laminated glass?
Toughened glass is heat-treated for strength and shatters into small, blunt pieces. Laminated glass bonds layers to a plastic interlayer that keeps broken glass in place. Toughened suits impact safety in doors and low windows, while laminated adds security and sound reduction as well.
Is Low-E glass worth the extra cost?
For most homes, yes. Low-E coatings typically add 10 to 20% to a window’s price, but they reduce heat transfer, which helps keep rooms comfortable and lowers heating and cooling use. The benefit is greatest when Low-E is combined with double glazing and a good frame.
Which window glass is best for reducing noise?
Laminated glass is the best choice for sound control because the interlayer dampens vibration. Combining laminated glass in a double glazed unit, with different glass thicknesses, improves results further. A sealed uPVC frame also matters, since gaps let noise through.
Choose the Right Window Glass With Ultimate Windows
We can help you match the glass to each window in your home, from safety glass to Low-E double glazing. Book a free measure and fixed-price quote, or call 1300 898 782 to speak with our team.
