Types Of Double Glazed Windows

Double glazed windows come in many different styles, frame materials and glass types, and each combination performs slightly differently. On this page, we will walk through the main types of double glazing, how they are built, and how to choose the best mix of glass, frame and window style for your home so you can improve comfort, energy efficiency and security with confidence.

Overview Of Double Glazed Windows

When you first start looking at the different types of double glazed windows, it can feel like a lot of jargon and options. In reality, most systems are variations on the same basic idea and, once you understand the main styles, glass types and frame materials, choosing double glazing becomes much easier.

Modern double glazing is standard in new windows for many Australian homes because it can cut winter heat loss by almost 30 percent, reduce summer heat gain by up to 77 percent and block a large proportion of harmful UV rays, which helps protect furnishings and reduce energy consumption. On top of that, quality double glazed windows and doors can improve sound insulation, increase security and even lift your property value.

What Double Glazing Is

At its core, double glazing is a sealed insulated glass unit built from two glass panes separated by a controlled air gap. Those two glass panes (often called double glazing glass) are held apart by a spacer bar and the cavity is filled with dry air or an inert gas such as argon to improve thermal insulation and energy efficiency.

Compared to single glazed windows with one sheet of regular glass, double glazed windows reduce heat transfer, cut heat loss in winter and keep more heat out in summer. That directly reduces heating and cooling costs, supports lower energy bills and helps shrink your carbon footprint. Because the air or gas gap also damps vibration, double glazing provides noticeable noise reduction from traffic, planes and neighbourhood chatter, which makes glazed windows far more comfortable in busy locations.

How Double Glazed Windows Are Built (Glass, Spacer, Gap, Frame)

Every double glazed unit is a small engineered system made up of:

• Glass types such as clear float glass, low E glass, laminated glass or toughened glass
• A spacer bar around the perimeter that creates the gap and holds a drying agent to control moisture
• A sealed air or gas filled space that provides thermal insulation and sound insulation
• Double glazing frames made from uPVC, aluminium, timber or composite frame materials

The glass panes are sealed to the spacer with specialised sealants to keep the air gap dry and stable. Gas fills like argon slow down heat transfer even more than dry air. The window frame or door frame then supports the insulated glass unit and must manage both structural loads and thermal performance. Different frame materials have very different insulation properties, so the window frame choice is just as important as the glass type when you want highly energy efficient windows and doors.

Glass Types Used In Double Glazed Windows

Glass types are where many of the performance differences between types of double glazing come from. Below are the main options you will see when comparing double glazed units.

Standard Double Glazed Units (Clear Float Glass)

Standard double glazing usually means two panes of clear float glass with a controlled gap in between, for example standard double glazing like 4 mm glass panes either side of a 12–16 mm air gap.

These double glazed units offer:

• A big step up in thermal insulation compared to single glazing
• Better energy efficiency and lower heating and cooling costs
• Basic noise reduction and good natural light

For many homes currently on single glazed windows, upgrading to this type of double glazing alone delivers significant energy savings and comfort improvements.

Low Emissivity (Low E) Double Glazing

Low E glazing uses a very thin, almost invisible coating on one pane that reflects long wave heat while allowing most visible light through.

This glass type helps:

• Reduce heat loss in winter by reflecting room heat back inside
• Cut solar heat gain in summer on sun exposed elevations
• Enhance energy efficiency so you can run air conditioning less and enjoy lower energy bills

Low E glass is one of the simplest ways to enhance energy efficiency without dramatically changing the appearance of your windows. It is especially effective when combined with argon gas in the cavity.

Acoustic Double Glazing

Acoustic double glazing is designed for stronger sound insulation where external noise is a problem. These double glazing units typically use:

• Thicker glass panes for added mass
• Asymmetrical glass thicknesses, for example 4 mm inside and 6 mm outside, to disrupt sound waves
• A slightly wider air gap for better acoustic performance

Used correctly, acoustic double glazing can make a dramatic difference in street facing bedrooms, living spaces near busy roads and homes under flight paths by reducing noise pollution and making rooms feel calmer.

Laminated And Toughened Safety Glass

Laminated and toughened glass are safety glass types that can be incorporated into many types of double glazed windows and double glazed doors.

• Toughened glass (also called tempered glass) is heat treated so it is stronger than float glass and, if it breaks, it crumbles into small blunt pieces instead of sharp shards.
• Laminated glass consists of two sheets of glass bonded together with a plastic interlayer, so if the pane breaks it stays in place rather than falling out.

These glass types increase security, reduce the risk of injury and are often required around floors, in glazed doors, bi fold doors, French doors, sliding doors and low level windows. They also contribute to noise reduction and can be paired with obscure glass for bathrooms and privacy zones.

Toned And Tinted Double Glazing

Toned and tinted double glazing uses coloured or reflective coatings to manage solar heat gain and glare. By tinting the double glazing glass or using reflective layers, you can:

• Reduce overheating on west and north facing glazed windows
• Cut harmful UV rays that fade floors, fabrics and furniture
• Control glare in living areas and home offices while still admitting natural light

Toned and obscure glasses can be combined to balance privacy, view and solar control.

Self Cleaning Glass Options

Self cleaning glass has a special surface treatment that reacts with sunlight and rain to break down dirt and help wash it away. This option is helpful for high, awkward or sloping glazing where regular cleaning is difficult, such as large bay windows, roof glazing or upper storey windows in modern home construction.

Triple Glazing And Vacuum Glazing (Related High Performance Options)

Triple glazing adds a third pane and two insulating gaps, while vacuum insulated glazing uses two panes of glass with a very thin vacuum gap between them. Both options:

• Further reduce heat transfer for maximum thermal performance
• Improve sound insulation where external noise is extreme
• Are most common in high performance projects with strict insulation and energy efficiency targets

They sit alongside standard types of double glazing as related high performance solutions rather than replacing them for typical Australian homes.

Window Styles Available With Double Glazing

Different window and door styles change how you use your home, how air flows and how indoor and outdoor spaces connect. Most common window styles are available as double glazed windows.

Casement Double Glazed Windows

Casement windows are hinged at the side and open outwards. Double glazed casement windows:

• Provide excellent ventilation and unobstructed views
• Seal tightly for strong insulation properties
• Suit both contemporary and traditional style façades

Flush casement windows sit level with the outer frame for a cleaner look that works well in many types of double glazed windows on modern homes.

Awning And Hopper Double Glazed Windows

Awning windows hinge at the top and push out from the bottom, while hopper windows hinge at the bottom and tilt in from the top. As double glazed units they:

• Allow ventilation during light rain
• Work well over sinks, benches or tight external spaces
• Offer secure airflow when slightly opened

They are a practical solution in kitchens, bathrooms and smaller rooms that still need fresh air.

Sliding Double Glazed Windows

Sliding double glazed windows move along tracks rather than swinging in or out. This style:

• Saves space where furniture or paths sit close to the wall
• Pairs well with sliding doors and stacking glazed doors for a consistent look
• Can use large glass panels to maximise views while maintaining insulation and energy efficiency

Double Hung And Sash Double Glazed Windows

Sash windows use vertically sliding sashes and are common in older single glazed homes. Double hung and sash double glazed windows:

• Preserve a traditional style while upgrading to double glazing
• Provide flexible ventilation from the top, bottom or both
• Can use slimline double glazing and timber frames to keep heritage proportions

Obscure glass or patterned obscure glasses are often used in sash windows for bathrooms or side windows to balance privacy and light.

Bay And Bow Double Glazed Windows

Bay windows and bow windows project from the façade and are built from multiple glazed windows joined at angles. With double glazing, these window styles:

• Bring in more natural light with multiple glass panes
• Create a sense of extra floor space and deep window seats
• Benefit greatly from improved thermal insulation, as the glass area is large

They are popular where outlook is important but you still want energy efficient, comfortable rooms.

Tilt And Turn Double Glazed Windows

Tilt and turn windows can tilt at the top for secure ventilation or turn inwards on side hinges for cleaning and full opening. Double glazed tilt and turn windows:

• Combine strong seals with flexible ventilation
• Make it easy to clean glass panes from inside upper storeys
• Work well in modern home construction where performance and practicality are both priorities

If you are comparing tilt and turn windows, note that hardware quality and professional installation matter a great deal because the sashes carry the weight of double glazing.

French Windows And Doors

French windows and French doors are side hinged glazed doors that open wide and typically use large glass panels. As double glazed doors they:

• Connect indoor and outdoor spaces gracefully
• Improve insulation and energy efficiency compared to older single glazed French doors
• Provide increased security when paired with modern multi point locks and toughened glass

They are ideal where you want a classic look with contemporary performance.

Sliding And Stacking Patio Doors

Sliding and stacking patio doors use wide double glazed panels that move along tracks. These glazed doors:

• Maximise views to the garden or patio
• Take up minimal internal space when opened
• Can be designed with multiple panels that stack aside to open up large sections of wall

With the right glass type and frame material, they balance solar heat gain control, sound insulation and ease of use very well.

Bi Fold Double Glazed Doors

Bi fold doors use multiple panels hinged together that fold and slide to one side, creating a wide clear opening between indoor and outdoor spaces. Double glazed bi fold doors:

• Are effective for entertaining zones where you want one large, flexible opening
• Use toughened or laminated glass and strong frames for safety and security
• Need careful specification to manage weight, hardware loads and thermal performance

They are one of the most striking types of double glazed doors when designed and installed correctly.

Frame Types For Double Glazed Windows

Glass choice is only half of the story. Window frames play a major role in insulation and energy efficiency, maintenance and appearance.

UPVC Double Glazed Windows

uPVC frames are a very common choice in highly energy efficient windows and doors. They:

• Provide excellent thermal insulation properties thanks to multi chambered profiles
• Are a durable material with low maintenance requirements
• Can be engineered to form very effective airtight seals around double glazing units

uPVC double glazed windows suit many homes where energy savings, reduced energy costs and low maintenance are key priorities.

Aluminium Double Glazed Windows

Aluminium frames are slim, strong and popular in modern home construction. In double glazing frames they:

• Allow narrow sightlines and larger spans of glass
• Can be finished in a wide range of powder coated colours
• Often rely on thermal breaks to improve thermal performance and reduce heat transfer

Thermally broken aluminium improves insulation and energy efficiency but does cost more than basic aluminium. It is a good choice where you prioritise a contemporary look and strong structural performance.

Timber Double Glazed Windows

Timber frames give double glazed windows a warm, natural appearance. Timber frames:

• Offer substantial insulating characteristics when maintained properly
• Work well in traditional style homes and heritage renovations
• Need regular painting or staining to manage moisture and maintain performance

For many period homes, timber double glazing is the best way to balance authenticity, comfort and energy savings.

Composite And Thermally Broken Frames

Composite frames combine materials, such as a timber inner frame with an external aluminium skin, or a mix of uPVC and aluminium. These frame materials are designed to:

• Minimise heat loss while remaining durable in harsh weather
• Provide low maintenance external finishes with a natural interior look
• Support strong thermal performance in cold and hot climates

Composite frames are worth considering where you want the best combination of appearance, durability and insulation.

Special Double Glazing Configurations

Alongside standard types of double glazed windows, there are special configurations that solve specific problems for existing windows and doors.

H3: Slimline Double Glazing For Heritage Or Narrow Frames

Slimline double glazing uses thinner glass and narrower gaps to create insulated glass units that fit into older, narrow window frames. This type of double glazing:

• Is ideal for heritage sash windows and character homes
• Maintains original profiles and sightlines while upgrading to double glazing
• Can still deliver meaningful improvements in thermal insulation and sound insulation compared to single glazed windows

It is a strong option when planning rules or aesthetics limit what you can change externally.

Secondary Glazing To Create A Double Glazed Effect On Existing Windows

Secondary glazing installs a second pane on the room side of existing glazed windows to create an extra air space. Unlike full replacement double glazing units:

• It leaves the original window frame and single glazing in place
• It adds an extra insulating layer to reduce heat loss and external noise
• It can be a cost effective solution for strata apartments and heritage façades

Secondary glazing is not quite as thermally efficient as sealed double glazing units with argon gas, but it still improves comfort, cuts energy consumption and preserves existing character.

Fire Protection And Safety Rated Double Glazing

In some locations, building codes and bushfire attack levels require specific safety or fire rated glazing. In these cases, types of double glazing may include:

• Special laminated safety glass or toughened safety glass combinations
• Frames and hardware rated for fire or impact resistance
• Glazed doors and windows designed to meet strict performance standards

Here it is especially important to combine appropriate glass types, frame materials and professional installation so performance on paper translates to real world safety.

How To Choose The Right Type For Your Home

With so many types of double glazed windows and double glazed doors available, choosing double glazing is really about matching performance, style and budget to how you live.

Matching Glass Type To Climate, Noise And Orientation

Start with your climate and site:

• In hot regions with strong sun, focus on low E glazing, toned glass and good thermal insulation to control solar heat gain and cooling costs.
• In cooler climates, clear double glazing with low E glass and argon gas fills can cut heat loss and keep your house warm with less heating.
• In noisy areas, look at acoustic double glazing and laminated glass to improve sound insulation and reduce external noise in bedrooms and living spaces.

Thinking about which elevations get the harshest sun and which rooms suffer most from traffic noise makes it easier to match glass type to real world needs.

Choosing Window Styles For Each Room

Next, consider how window styles will work room by room:

• Living rooms and kitchens often benefit from casement windows, tilt and turn windows, large sliding doors or bi fold doors that connect strongly to outdoor spaces.
• Bedrooms may need quieter glass types, sash windows or awning styles for secure ventilation, plus obscure glass in adjoining ensuites.
• Older homes may look best with double glazed sash windows or traditional style casement windows, while a modern home might lean toward large glazed windows and doors with slim frames.

Windows and doors should match how you actually use each space, not just how they look in a brochure.

Selecting Frame Materials To Suit Design, Maintenance And Budget

Finally, weigh up frame material and budget:

• uPVC frames are low maintenance, highly energy efficient and cost effective for many family homes.
• Aluminium suits contemporary designs and big openings, particularly when you specify thermally broken frames for better insulation.
• Timber frames look superb in character homes but do require ongoing care.
• Composite frames are a premium choice when you want durability, warmth and strong thermal performance.

Whichever type of double glazing you choose, the quality of the double glazing units, the window frames and the professional installation will all affect long term performance and energy savings. Reliable aftercare and good warranties are also important because they protect your investment over time.

Ready To Compare Double Glazed Window Types For Your Home?

Understanding the main types of double glazed windows, glass types and frame materials puts you in a much stronger position to choose what actually suits your home. The right combination can improve insulation and energy efficiency, reduce heat loss and heat gain, cut external noise, increase security, and support increased property value while lowering ongoing energy costs and your carbon footprint.

If you are ready to take the next step, use Trade Heroes to connect with vetted double glazing specialists in your area. You can compare different types of double glazing, review experience and qualifications, and request quotes from installers who understand local conditions, Australian Standards and modern energy efficiency requirements.

That way you can choose the right double glazed windows for each room with confidence, work with a trusted trade professional from the Trade Heroes directory, and enjoy a quieter, more comfortable and more energy efficient home, knowing your investment is working hard for you now and into the future.