Green Star is Australia’s primary sustainability rating system for buildings, administered by the Green Building Council of Australia (GBCA). Aluminium facade systems contribute to Green Star credits across energy, materials, lifecycle, durability, and indoor environment quality - with energy performance typically delivering the largest impact. For projects pursuing Green Star certification, the facade is not a minor line item. It is one of the most significant building elements the rating assesses.
This article covers the specific Green Star credit categories where aluminium facades contribute, what the all-electric mandate means for facade design, the embodied carbon picture in context, and practical advice for project teams preparing Green Star submissions.
Why Does Green Star Matter for Facade Specification?
Green Star is no longer a voluntary aspiration. State and territory governments increasingly mandate minimum ratings for publicly funded buildings. Institutional developers - superannuation funds, REITs, and large developers targeting premium and A-grade assets - routinely require 5 or 6 Star ratings.
For architects, ESD consultants, and developers, the facade specification directly affects multiple Green Star credit categories. Getting the facade right early - ideally at concept design - simplifies the path to the target rating. Getting it wrong creates expensive redesign loops later.
How Does the Facade Affect Energy Credits?
The energy credit category is typically where the facade has its largest influence on a Green Star rating. The building envelope is the primary determinant of heating and cooling loads, and the facade is the largest component of that envelope.
NCC Section J sets the baseline energy efficiency requirements for external walls (J1.5) and glazing (J1.6). Green Star does not simply require Section J compliance - it rewards projects that exceed those baselines. The further a building’s energy performance moves beyond the Deemed-to-Satisfy minimum, the more credits it earns.
Two facade system types contribute directly here.
Rainscreen cladding with continuous insulation. An aluminium rainscreen system like interloQ, installed over a continuous insulation layer, creates a high-performance wall assembly. The ventilated cavity behind the cladding manages moisture, while the unbroken insulation layer delivers thermal resistance without the bridging that occurs in framed wall construction. This combination can significantly exceed minimum wall R-value requirements, contributing to energy credits.
Curtain wall with thermally broken frames. The 165CW unitised curtain wall system uses thermally broken glazing adaptors - a polyamide strip separating internal and external aluminium faces. Combined with high-performance insulated glass units (IGUs) - low-E coatings, argon fill, and appropriate solar heat gain coefficient (SHGC) tuning for the orientation and climate zone - this directly reduces heat transfer through the glazed portions of the facade. Glazing performance is one of the most scrutinised elements in energy modelling for Green Star.
The facade does not earn energy credits in isolation. It is modelled as part of the whole building, and its contribution depends on climate zone, orientation, window-to-wall ratio, and building services design. But if the facade performs poorly, building services have to work harder to compensate - and that makes the energy credits harder to achieve.
What Do the Materials Credits Assess?
Green Star’s materials category assesses responsible sourcing, recycled content, and lifecycle impacts. This is where the intrinsic properties of aluminium as a material become relevant.
Recyclability. Aluminium is 100% recyclable without loss of quality. The alloy recovered from a demolished building can be re-melted and re-formed into new extrusions or sheet that is structurally and aesthetically identical to primary material. More than 90% of aluminium used in construction is recovered and recycled at end of life - aluminium has genuine scrap value, so demolition contractors actively recover it.
Recycled content. Recycled aluminium requires approximately 95% less energy to produce than primary aluminium smelted from bauxite ore. Specifying suppliers who can demonstrate recycled content in their supply chain contributes to the responsible sourcing credits. Material data sheets showing recycled content percentages are the standard evidence.
Responsible sourcing chain. Green Star recognises third-party certification schemes for responsible material sourcing. Suppliers who can provide chain-of-custody documentation or environmental product declarations (EPDs) make it easier for project teams to capture these credits.
How Does Lifecycle Assessment Factor In?
Green Star lifecycle assessment credits consider embodied carbon over 60 or more years - not just the impact at the point of manufacture. This is where a common objection to aluminium needs honest context.
Primary aluminium has relatively high embodied carbon at production, typically around 12-17 kg CO2e/kg depending on the smelter’s energy source. That figure is higher per kilogram than steel, timber, or fibre cement. This is a legitimate consideration, and it would be misleading to dismiss it.
However, three factors materially change the lifecycle calculation.
Recycled content reduces the number dramatically. Recycled aluminium drops to approximately 0.5-2 kg CO2e/kg. As recycled content in the global supply chain increases - driven by economics and regulation - the effective embodied carbon of aluminium products continues to fall.
No replacement cycles. Aluminium does not corrode, rot, or degrade in normal service conditions. A well-installed aluminium facade will last the entire design life of the building without replacement. Compare this to materials with lower upfront embodied carbon that require replacement at 15, 20, or 25 years. Over a 60-year lifecycle assessment, the material that lasts without replacement often has a lower cumulative carbon impact than the material that needs replacing twice.
End-of-life recovery. At demolition, aluminium has high scrap value and is actively recycled back into the supply chain. Many other building materials - fibre cement, composite panels with mixed cores, rendered systems - go to landfill at end of life. Green Star lifecycle assessment rewards materials that re-enter the circular economy rather than becoming waste.
The lifecycle calculation also accounts for material efficiency. interloQ panels at 1.8-3.5mm thickness and element13 panels at 3mm (8.13 kg/m2) use relatively modest amounts of material per square metre of facade. The durability and recyclability of that material over the building’s life is where the lifecycle credit contribution sits.
Does Durability Contribute to Green Star?
Yes. Green Star rewards materials that last the building’s design life without replacement. This is assessed under the durability and resilience credits.
Valmond & Gibson products carry warranties of up to 20 years on substrate and coating when installed by a qualified installer. The warranted period is the minimum, not the expected service life. Aluminium facades installed in the 1970s and 1980s remain in service today, performing well with nothing more than routine cleaning.
This durability reduces whole-of-life material consumption, waste generation, and maintenance burden - all of which Green Star credits recognise.
How Does the Facade Affect Indoor Environment Quality Credits?
Green Star assesses occupant comfort through thermal comfort, daylight, and ventilation credits. The facade plays a direct role in all three.
Thermal comfort. Glazing selection in 165CW curtain wall - SHGC tuning, low-E coatings, argon-filled IGUs - controls solar heat gain and radiant asymmetry near the facade. Thermally broken frames reduce the cold-surface effect in winter. These factors directly affect the thermal comfort modelling that Green Star requires.
Daylight. The window-to-wall ratio and glazing visible light transmittance (VLT) determine how much natural light reaches occupied spaces. 165CW’s mullion width of 86mm (including the 10mm nominal gap) keeps framing slender, maximising the glazed area within each module.
External shading. conneQt aluminium battens and interloQ panels can serve as external shading elements - horizontal blades, vertical fins, or brise-soleil configurations. External shading is significantly more effective than internal blinds at controlling solar heat gain, and it contributes to both energy and comfort credits. The 165CW system includes integrated horizontal and vertical sunshade brackets with concealed nutplate connections, designed specifically for this application.
What Does the All-Electric Mandate Mean for Facades?
Green Star v1.3, taking effect in May 2026, requires new buildings pursuing Green Star certification to be all-electric. No gas connections for heating, hot water, or cooking.
This has a direct implication for facade thermal performance. Without gas-fired heating as a fallback, the building envelope must work harder to maintain comfortable internal temperatures in cooler months. An underperforming facade on an all-electric building means the electric heating system runs more, consuming more energy and making the energy credits harder to achieve.
The practical result is that facade thermal performance - continuous insulation behind rainscreen systems, thermally broken curtain wall frames, high-performance glazing - becomes more important under the all-electric mandate, not less. Projects that previously relied on efficient gas heating to compensate for moderate facade performance will need to reconsider that approach.
What Should Project Teams Do for Green Star Submissions?
Practical advice for architects, ESD consultants, and developers working on Green Star projects.
Engage the ESD consultant early. Understand which credits the facade is expected to contribute to before the specification is finalised. Different credit categories require different evidence, and the facade supplier needs to know what documentation to prepare.
Request material data early. Ask suppliers for recycled content data, thermal property documentation, warranty details, and any available EPDs. Valmond & Gibson can provide material data sheets with recycled content information, thermal performance characteristics, coating specifications, and durability documentation for Green Star submissions.
Model the facade as part of the whole building. Energy credits are assessed through whole-building energy modelling. Early coordination between the facade designer and the energy modeller avoids late-stage surprises.
Consider the lifecycle, not just the upfront numbers. Green Star increasingly rewards materials that perform well over the full building life. A material with higher upfront embodied carbon but no replacement cycles and full recyclability may score better than a lower-carbon material that needs replacing.
Document everything. Green Star assessors require evidence, not claims. Test reports, material certificates, warranty documentation, and supplier declarations all need to be compiled as part of the submission. Products supported by comprehensive compliance documentation - CSIRO combustibility test reports, weather performance testing to AS/NZS 4284, coating performance to AAMA 2605 - simplify this process.
Where Does This Leave Aluminium Facade Systems?
Aluminium facade systems contribute to Green Star ratings across multiple credit categories. The energy credit is typically the largest single contribution, driven by rainscreen thermal performance and curtain wall glazing design. The materials, lifecycle, durability, and indoor environment credits provide additional pathways.
The all-electric mandate in Green Star v1.3 increases the importance of facade thermal performance for new projects from mid-2026 onward. Projects that take the facade seriously at concept design - not as an afterthought at tender stage - will find the path to their target rating more straightforward.
Valmond & Gibson products are non-combustible, durable, fully recyclable, and supported by the technical documentation that Green Star submissions require. For project teams working toward a Green Star rating, that combination of performance and evidence is what moves credits from possible to confirmed.
Related Reading
- NCC Section J: Thermal Performance Requirements for Facades
- Aluminium Facade Sustainability: Lifecycle, Recyclability, and Embodied Carbon
- Thermal Bridging in Aluminium Facade Systems
- How Long Does Aluminium Cladding Last?
Last updated: 4 April 2026