Thermally Broken Aluminium Windows

Thermally Broken Aluminium Windows

Thermally broken aluminium windows are high-performance window systems designed to reduce heat transfer through the aluminium frame by incorporating an insulating barrier between the internal and external aluminium sections.

For Australian homes and buildings where thermal comfort and energy performance are important, thermally broken aluminium windows can provide a significant performance advantage over conventional aluminium framing when combined with appropriately specified glazing.

They are particularly relevant for:

  • Energy-efficient homes
  • Architect-designed residences
  • Premium renovations
  • Double-glazed window packages
  • Commercial buildings
  • Schools and education projects
  • Multi-residential developments
  • Projects in colder or more demanding climates
  • Buildings seeking improved whole-window thermal performance

However, the thermal break is only one part of the system.

Glass selection, frame design, window configuration, orientation, seals, installation and the surrounding building envelope all influence actual performance.

EZ Windows supplies aluminium window and door systems for residential, architectural and commercial projects, including thermally broken solutions where appropriate to the project specification.

What Are Thermally Broken Aluminium Windows?

Thermally broken aluminium windows are aluminium window systems containing a low-conductivity barrier that separates the internal and external aluminium sections of the frame.

The purpose of this barrier is to reduce the direct transfer of heat through the aluminium.

Conventional aluminium is an excellent structural material, but it is also a good conductor of heat.

Without a thermal break, the aluminium frame can provide a relatively direct path for heat to move between the inside and outside of a building.

A thermally broken system interrupts this conductive pathway.

The result can be improved thermal performance when the frame is combined with suitable glazing and incorporated correctly into the building.

What Is a Thermal Break?

A thermal break is a section of low-conductivity material incorporated between internal and external aluminium frame components.

Rather than having aluminium continuously connecting the inside and outside faces of the frame, the thermal barrier separates those sections.

In simple terms:

Outside aluminium → thermal barrier → inside aluminium

The thermal barrier is engineered as part of the proprietary window or door framing system.

It is not something simply added to a conventional window after manufacture.

The complete frame must be designed to operate structurally and mechanically while incorporating the thermal barrier.

Why Does Aluminium Need a Thermal Break?

Aluminium is naturally highly conductive.

This is useful in many engineering applications, but in a window frame it means heat can move relatively easily through conventional aluminium sections.

During winter, heat from inside the building can transfer toward colder external conditions.

During summer, external heat can transfer toward the interior.

A thermal break is designed to reduce this direct conductive pathway.

That can improve the overall thermal characteristics of the window or door.

Standard Aluminium vs Thermally Broken Aluminium Windows

The main difference is the construction of the frame.

Standard Aluminium Windows

A conventional aluminium window generally has aluminium connecting the internal and external portions of the frame.

Advantages can include:

  • Proven window-system designs
  • Strength
  • Durability
  • Architectural appearance
  • Broad product availability
  • Competitive pricing
  • Large range of configurations
  • Low maintenance

Standard aluminium remains suitable for many Australian building applications.

Thermally Broken Aluminium Windows

Thermally broken systems separate internal and external aluminium sections with a low-conductivity barrier.

Potential advantages include:

  • Reduced heat transfer through the frame
  • Improved whole-window thermal performance
  • Better compatibility with high-performance glazing strategies
  • Improved internal comfort
  • Reduced internal frame-surface temperature differences
  • Potential reduction in condensation risk under certain conditions
  • Suitability for higher-performance building designs

They generally involve more complex profiles and manufacturing processes and can therefore cost more than conventional aluminium systems.

Do Thermally Broken Aluminium Windows Make a Difference?

Yes. A properly designed thermal break can materially reduce heat transfer through an aluminium window frame compared with a similar conventional aluminium frame.

The actual improvement depends on the complete system.

A window is made up of much more than the aluminium profile.

Performance is influenced by:

  • Frame design
  • Thermal-break design
  • Glass
  • Insulated glass unit configuration
  • Low-E coatings
  • Spacer system
  • Window size
  • Opening type
  • Seals
  • Hardware
  • Air leakage
  • Installation
  • Orientation
  • Shading

For this reason, buyers should compare whole-window performance, not simply whether a product is described as thermally broken.

Thermally Broken Aluminium Windows and Double Glazing

Thermally broken framing and double glazing perform different functions but can work together.

Double glazing reduces heat transfer through the glazed component by using two panes of glass separated by a sealed cavity.

A thermal break reduces conductive heat transfer through the aluminium frame.

Combining the two can therefore address two important components of the complete window:

Glass performance + frame performance

This is why thermally broken framing is often considered alongside double glazing for higher-performance buildings.

However, simply combining double glazing and a thermal break does not automatically guarantee a particular energy rating.

The complete system must still suit the project.

Is Double Glazing Enough Without Thermally Broken Frames?

That depends on the required performance.

Double glazing can improve the thermal characteristics of the glazed area while the conventional aluminium frame remains comparatively conductive.

For many projects, that may still provide an appropriate solution.

For projects requiring higher levels of thermal performance, however, frame conductivity can become increasingly important.

This is why architects, energy assessors and building designers may specify thermally broken framing together with appropriate glazing.

The correct decision should be based on the project’s performance requirements rather than assuming one solution is universally necessary.

What Are the Benefits of Thermally Broken Aluminium Windows?

The primary benefit is reduced heat transfer through the aluminium frame, but this can contribute to several broader building-performance advantages.

Improved Thermal Performance

Reducing direct conductivity through the frame can improve whole-window thermal performance.

This becomes particularly valuable when combined with suitable double glazing.

Improved Internal Comfort

Windows are a significant interface between internal and external environments.

Improving frame and glazing performance can help reduce temperature differences around window areas.

This can contribute to more consistent internal comfort.

Reduced Heat Loss

During colder conditions, a thermally broken frame can reduce heat transfer through the aluminium compared with conventional framing.

This can help support a building’s overall thermal strategy.

Reduced Heat Gain

During warmer conditions, the thermal break can also reduce conductive heat transfer through the frame.

Solar heat gain through the glass must still be considered separately.

Shading, orientation and glazing selection remain important.

Reduced Condensation Risk

Thermally broken frames can reduce the likelihood of internal aluminium surfaces becoming as cold as comparable conventional aluminium frames under certain conditions.

This may reduce condensation risk.

However, thermally broken aluminium windows do not guarantee that condensation will never occur.

Condensation depends on:

  • Indoor humidity
  • External temperature
  • Internal temperature
  • Ventilation
  • Glass temperature
  • Frame temperature
  • Thermal bridges
  • Building insulation
  • Occupancy
  • Moisture generation

A complete building approach is therefore necessary.

Architectural Design Freedom

One of aluminium’s major advantages is its ability to provide contemporary architectural framing while supporting substantial glazing.

Thermally broken systems can retain many of these architectural advantages while improving frame thermal performance.

Depending on the selected system, applications can include:

  • Large fixed windows
  • Awning windows
  • Sliding windows
  • Hinged doors
  • Sliding doors
  • Stacker doors
  • Architectural glazing combinations
  • Custom window configurations

Are Thermally Broken Aluminium Windows Energy Efficient?

Thermally broken aluminium windows can form an important part of an energy-efficient building, particularly when combined with suitable glazing and building-envelope design.

But no window should be judged on the frame alone.

Whole-window performance is what matters.

Important factors include:

  • Frame thermal performance
  • Glass performance
  • Window-to-wall ratio
  • Window orientation
  • Solar exposure
  • External shading
  • Air leakage
  • Building insulation
  • Installation
  • Climate
  • Building design

Where a project has specific energy requirements, the selected windows should be coordinated with the approved energy assessment.

Understanding Whole-Window Performance

One of the most important concepts when comparing windows is that the frame and glass must be considered together.

A high-performance glass unit installed in a poorly performing frame may not provide the same whole-window result as the same glass installed in a higher-performing frame.

Likewise, an excellent thermally broken frame cannot compensate for every inappropriate glazing choice.

This is why professional window specification considers the complete assembly.

Understanding U-Value

U-value is commonly used to describe the rate of heat transfer through a building component.

For windows, a lower whole-window U-value generally indicates lower heat transfer through the complete window assembly.

It is important to distinguish between:

  • Centre-of-glass performance
  • Glass-only performance
  • Whole-window performance

When comparing window systems, whole-window values are generally more meaningful than considering the glass alone.

Project-specific requirements should be confirmed against the applicable energy assessment and approved documentation.

Understanding Solar Heat Gain

Thermal conductivity is only one aspect of window performance.

Solar radiation passing through glass can also have a major impact on internal temperatures.

This means a window may need to balance:

  • Insulation
  • Solar heat gain
  • Natural light
  • Orientation
  • Shading
  • Climate
  • Architectural design

For example, a large west-facing glazed area may require a different glazing strategy from a protected south-facing window.

The best specification depends on the building.

Thermally Broken Aluminium Windows and Low-E Glass

Low-emissivity, or Low-E, glass is often considered alongside thermally broken aluminium frames.

Low-E coatings are designed to modify radiant heat transfer through the glazing.

A high-performance window package might therefore combine:

  • Thermally broken aluminium framing
  • Double glazing
  • Low-E glass
  • Appropriate IGU cavity
  • Suitable spacer technology
  • Correct seals
  • Appropriate installation

The exact combination should be selected according to the project rather than treated as a universal specification.

Thermally Broken Aluminium Awning Windows

Awning windows can be manufactured using suitable thermally broken systems where available.

They can provide a combination of:

  • Ventilation
  • Contemporary appearance
  • Improved frame thermal performance
  • Double-glazing compatibility

Awning-window size, hardware and glass weight must remain within the selected system’s capabilities.

Where architectural window shrouds surround an awning window, opening clearance should also be coordinated.

Thermally Broken Fixed Windows

Fixed windows are particularly relevant to high-performance architectural design because they can accommodate substantial areas of glazing without requiring an operable sash.

They are commonly used for:

  • Living areas
  • Feature glazing
  • Stairwells
  • Architectural façades
  • High-level windows
  • Commercial projects

A thermally broken fixed frame combined with appropriately selected double glazing can form part of a high-performance façade strategy.

Thermally Broken Sliding Windows

Thermally broken sliding systems may be available depending on the selected product range.

Sliding windows provide the practical advantage of operating without projecting externally or internally.

Because sliding systems require tracks, moving panels and seals, their complete performance characteristics should be considered rather than assuming every thermally broken configuration performs identically.

Thermally Broken Aluminium Doors

Thermal breaks are not limited to windows.

Suitable aluminium door systems can also incorporate thermal barriers.

Applications may include:

  • Hinged doors
  • Sliding doors
  • Large architectural doors
  • Selected stacker configurations

Door systems require particular attention because of their size, moving panels, hardware and thresholds.

Thermally Broken Aluminium Sliding Doors

Large glazed sliding doors can represent a substantial area of the external building envelope.

Using high-performance glass while ignoring the frame can reduce the effectiveness of the overall specification.

Thermally broken sliding-door systems can therefore be considered for projects requiring improved thermal performance.

However, large double-glazed panels can be extremely heavy.

Panel dimensions affect:

  • Glass weight
  • Roller selection
  • Frame capacity
  • Hardware
  • Transport
  • Site handling
  • Installation

Practical maximum sizes depend on the selected system, glass, wind pressure, hardware and project conditions.

Door Thresholds and Weather Performance

Thermal performance should never be considered independently from practical building-envelope requirements.

Large external doors must also coordinate with:

  • Paving
  • Decking
  • Balcony levels
  • Falls
  • Drainage
  • Flashings
  • Waterproofing membranes
  • Sealants
  • Adjacent walls and cladding

No external door should be represented as completely waterproof under every possible condition.

Correct system selection, installation and surrounding construction are essential to weather performance.

Thermally Broken Windows for New Homes

New construction provides an opportunity to integrate window performance into the building design from the beginning.

Thermally broken windows may be considered during:

  • Energy assessment
  • Architectural design
  • Window scheduling
  • Glass specification
  • Façade design
  • Structural coordination
  • Shading design
  • Window-shroud design
  • Construction documentation

Early specification allows the window system to be considered as part of the complete building rather than as a late substitution.

Thermally Broken Windows for Renovations

Thermally broken aluminium windows can also be considered for substantial renovations and window replacement.

Existing buildings can introduce additional considerations including:

  • Existing opening sizes
  • Wall construction
  • Existing flashings
  • Internal reveals
  • External cladding
  • Insulation
  • Waterproofing
  • Access
  • Structural conditions

Replacing an older window with a higher-performing product can improve the window itself, but the overall building performance will continue to depend on the surrounding construction.

Thermally Broken Windows for Architectural Homes

Premium residential architecture frequently incorporates large glazed openings.

These can create outstanding natural light and visual connections but also increase the importance of thermal design.

Architectural considerations can include:

  • Large fixed glazing
  • Floor-to-ceiling windows
  • Oversized sliding doors
  • Corner windows
  • Window shrouds
  • Deep façade reveals
  • Privacy screens
  • Custom powder-coated finishes

Thermally broken aluminium can provide an option where architectural appearance and improved frame performance are both priorities.

Thermally Broken Windows for Commercial Buildings

Thermally broken aluminium systems can also be suitable for commercial and institutional applications including:

  • Offices
  • Schools
  • Universities
  • Childcare centres
  • Government buildings
  • Multi-residential developments
  • Community facilities
  • Selected retail and mixed-use buildings

Commercial projects may have detailed requirements relating to energy performance, structural design, glazing, acoustics and façade performance.

These requirements should be established by the relevant project professionals.

Thermally Broken Aluminium Windows for Architects

For architects and building designers, thermally broken aluminium provides another specification tool for balancing aesthetics and performance.

Important considerations include:

  • Frame dimensions
  • Sightlines
  • Mullion locations
  • Glass specification
  • Opening configuration
  • Thermal performance
  • Solar performance
  • Powder-coat finish
  • Shading
  • Window shrouds
  • Screens
  • Façade integration

EZ Windows can manufacture or supply according to approved project documentation and the agreed scope.

Where project-specific engineering, energy assessment or certification is required, it remains subject to the appropriately appointed professional.

Thermally Broken Aluminium Windows for Builders

Builders should establish the required performance specification before ordering.

Useful information includes:

  • Architectural plans
  • Window schedule
  • Energy report
  • Glass specification
  • Opening sizes
  • Window configurations
  • Door configurations
  • Powder-coat colours
  • Screens
  • Required delivery dates
  • Installation scope

Early coordination reduces the risk of selecting a window package that does not correspond with the approved project requirements.

Custom Thermally Broken Aluminium Windows

Thermally broken aluminium systems can offer considerable design flexibility, subject to the capabilities of the selected system.

Customisation may include:

  • Window dimensions
  • Mullion positions
  • Transoms
  • Fixed and opening combinations
  • Glass specification
  • Door configurations
  • Powder-coat finish
  • Hardware
  • Screens

Not every configuration or dimension is possible in every system.

Large or unusual windows may require specific consideration of glass, wind pressure, framing, hardware and structural requirements.

What Colours Are Available?

Thermally broken aluminium windows can generally be powder coated in colours available for the selected system and coating specification.

Popular architectural approaches include finishes that coordinate with:

  • Roofing
  • Cladding
  • Render
  • Brickwork
  • Window shrouds
  • Privacy screens
  • Architectural metalwork

The applicable powder-coat warranty depends on the actual coating system selected and applied, manufacturer, product range, environmental exposure, installation, cleaning, maintenance and supplier terms.

Colour selection alone does not determine warranty coverage.

How Much Do Thermally Broken Aluminium Windows Cost?

Thermally broken aluminium windows generally cost more than comparable standard aluminium windows because the framing system and manufacturing process are more complex.

There is no meaningful universal price that applies to every project.

Cost depends on factors including:

  • Window dimensions
  • Window type
  • Door type
  • Frame system
  • Glass specification
  • Double glazing
  • Low-E coatings
  • Glass thickness
  • Hardware
  • Quantity
  • Powder-coat finish
  • Screens
  • Project location
  • Delivery
  • Installation
  • Access

The most reliable approach is to obtain a quotation based on the actual project documentation.

Are Thermally Broken Aluminium Windows Worth the Extra Cost?

They can be where the project places sufficient value on thermal performance, comfort or energy efficiency to justify the additional investment.

They are particularly worth considering where:

  • The approved energy assessment requires higher window performance
  • Large glazed areas are proposed
  • Double glazing is already specified
  • The climate increases heating or cooling demands
  • Internal comfort is a major design objective
  • The project is targeting higher building-envelope performance
  • Premium architectural outcomes are required

For other projects, a conventional aluminium system with appropriate glazing may remain a practical solution.

The correct decision depends on the project rather than on a universal rule.

Thermally Broken Aluminium vs uPVC Windows

Both thermally broken aluminium and uPVC can be used in energy-conscious window design, but they have different characteristics.

Thermally broken aluminium is particularly attractive where projects prioritise:

  • Aluminium aesthetics
  • Architectural profiles
  • Large glazing
  • Structural capability
  • Powder-coated finishes
  • Commercial-style detailing

uPVC offers different thermal and material characteristics.

A detailed comparison should consider whole-window performance, size capability, architecture, durability, maintenance, budget and project requirements rather than material alone.

Thermally Broken Aluminium vs Timber Windows

Timber naturally has relatively low thermal conductivity compared with aluminium, while thermally broken aluminium uses an engineered barrier to reduce frame conductivity.

The choice can depend on:

  • Architectural style
  • Maintenance preferences
  • Frame dimensions
  • Window size
  • Finish
  • Environmental exposure
  • Thermal objectives
  • Budget

Neither material should be selected solely on one characteristic.

Do Thermally Broken Windows Reduce Noise?

A thermal break is primarily intended to reduce heat transfer through the frame.

It should not be confused with an acoustic glazing system.

Acoustic performance depends heavily on:

  • Glass composition
  • Glass thickness
  • Laminated glass where specified
  • Cavity configuration
  • Seals
  • Window opening type
  • Frame
  • Installation
  • Surrounding construction

Thermally broken windows can form part of an acoustically considered façade, but the thermal break itself does not make a window soundproof.

Do Thermally Broken Windows Stop Condensation?

No window system can guarantee the elimination of condensation in every environment.

Thermally broken framing can increase internal frame-surface temperatures compared with conventional aluminium under certain conditions and therefore may reduce condensation risk.

But internal humidity and environmental conditions remain critical.

Ventilation and moisture management within the building must also be considered.

How Long Do Thermally Broken Aluminium Windows Last?

Service life depends on the window system, installation, environmental exposure, use and maintenance.

Aluminium itself is widely used because of its durability and resistance to many common deterioration mechanisms.

Regular maintenance should include:

  • Cleaning aluminium surfaces
  • Cleaning glass
  • Keeping tracks clear
  • Keeping drainage paths clear
  • Maintaining operating hardware
  • Inspecting seals where appropriate
  • Following powder-coating maintenance requirements

More aggressive environments may require increased cleaning frequency.

Compliance and Project Responsibilities

Thermally broken aluminium windows must be appropriately selected for the particular project.

EZ Windows manufactures and supplies within its agreed scope and according to approved project information.

Unless separately engaged for a specific professional service, EZ Windows is not acting as the project’s architect, structural engineer, façade engineer, energy assessor, acoustic consultant, waterproofing consultant, building surveyor or certifier.

Project-specific engineering, energy-performance requirements, acoustic requirements, waterproofing and statutory approvals remain subject to the relevant appointed professionals and authorities.

Final dimensions and specifications must be checked and approved by the responsible party before manufacture.

Product information should not be interpreted as project-specific engineering or certification.

Warranty and Maintenance

EZ Windows is an AGWA member and generally provides a six-year product guarantee, subject to the applicable written terms, exclusions and conditions.

Where installation is undertaken by EZ Windows under an accepted installation scope, the installation warranty is generally one year, subject to the applicable terms.

Powder-coat warranty coverage depends on the coating system actually selected and applied, powder manufacturer, product range, environmental exposure, coastal or industrial conditions where relevant, installation, cleaning, maintenance and applicable supplier terms.

Frequently Asked Questions About Thermally Broken Aluminium Windows

What is a thermally broken aluminium window?

A thermally broken aluminium window contains an insulating barrier separating internal and external aluminium frame sections to reduce heat transfer through the frame.

What does thermally broken mean?

It means the direct conductive pathway through the aluminium frame has been interrupted by a lower-conductivity material incorporated into the framing system.

Are thermally broken aluminium windows better?

They generally provide improved frame thermal performance compared with conventional aluminium framing, but whether they are the better choice depends on the project’s requirements and budget.

Do thermally broken windows need double glazing?

Not necessarily in every possible system, but thermally broken frames are commonly paired with double glazing when improved whole-window thermal performance is required.

Is double glazing the same as thermally broken aluminium?

No.

Double glazing relates primarily to the glass assembly. A thermal break relates to the aluminium frame.

The two technologies can be combined.

Is double glazing worth having without a thermal break?

It can be.

The appropriate combination depends on the project’s required whole-window performance, climate, budget and approved energy assessment.

Are thermally broken aluminium windows energy efficient?

They can contribute significantly to an energy-efficient window package when combined with appropriate glass, installation and building design.

Do thermally broken windows keep heat out?

They reduce conductive heat transfer through the aluminium frame compared with conventional aluminium. Solar heat entering through glass must be managed through appropriate glazing, orientation and shading.

Do thermally broken windows keep heat in during winter?

They can reduce conductive heat loss through the frame and therefore contribute to improved winter thermal performance.

Do thermally broken windows stop condensation?

No. They can reduce condensation risk under some conditions but cannot guarantee condensation will never occur.

Are thermally broken windows soundproof?

No. Acoustic performance requires consideration of glass, seals, frame, opening configuration, installation and surrounding construction.

Can thermally broken aluminium windows be custom made?

Yes, many thermally broken systems allow project-specific dimensions and configurations within the capabilities of the selected system.

Can thermally broken aluminium be used for sliding doors?

Yes, suitable thermally broken sliding-door systems are available, subject to project and system requirements.

Are thermally broken windows suitable for Melbourne?

They can be particularly relevant to Melbourne projects where winter heat loss, summer heat gain and year-round internal comfort are important design considerations.

The actual requirement should still be determined according to the particular building and its approved energy assessment.

Are thermally broken aluminium windows more expensive?

Generally, yes. The profiles and manufacturing processes are more complex than conventional aluminium systems.

The actual difference depends on the complete window package.

What glass should be used with thermally broken windows?

There is no universal glass specification.

The appropriate glass depends on energy, safety, acoustic, solar, size and architectural requirements.

What is better: standard aluminium or thermally broken aluminium?

Neither is universally better for every project.

Standard aluminium can be an appropriate and economical solution for many buildings, while thermally broken aluminium is particularly valuable where improved frame thermal performance is required.

Request a Quote for Thermally Broken Aluminium Windows

If your project requires thermally broken aluminium windows, double glazing or a higher-performance aluminium window and door package, EZ Windows can review the project information and provide a quotation based on the required scope.

For an accurate quotation, provide:

  • Architectural drawings
  • Window and door schedule
  • Energy assessment where applicable
  • Glass specification
  • Window dimensions
  • Door dimensions
  • Opening configurations
  • Powder-coat colour
  • Screens
  • Project location
  • Required timeframe
  • Supply-only or installation requirements

For builders, architects, developers and homeowners, early window specification makes it easier to coordinate performance, appearance, construction and budget.

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