Aluminium Facades for Office Buildings

Office buildings demand facades that deliver transparency, thermal performance, and a professional image that holds up over time. In Australia, commercial office facades are typically built around curtain wall glazing systems complemented by solid spandrel panels, external sun shading, and feature cladding - with aluminium forming the backbone of all four. The combination of non-combustibility, long service life, and design flexibility makes aluminium the dominant facade material for Class 5 buildings from mid-rise suburban offices through to premium CBD towers.

This article covers the NCC requirements for office building facades, the systems that address each part of the envelope, and the performance factors that drive specification decisions on commercial projects.

What does the NCC require for office building facades?

Office buildings fall under NCC Class 5 - buildings used for professional or commercial purposes that are not shops, factories, or warehouses. Think office floors in commercial towers, standalone office buildings, and the commercial levels of mixed-use developments.

Class 5 buildings of four or more storeys require Type A construction under the NCC. For external walls, Type A construction means non-combustible materials throughout the facade assembly - cladding, framing, insulation, and sarking must all satisfy the non-combustibility requirement under C2D10 of NCC 2022.

Aluminium alloy is explicitly deemed non-combustible under C2D10(5)(d) when it is composed entirely of aluminium. This means solid aluminium facade systems - curtain wall framing, solid panels, and extruded battens - satisfy the requirement through the Deemed-to-Satisfy pathway without needing fire engineering assessments or large-scale facade testing.

This matters commercially. Where combustible or composite materials are proposed on a Type A building, the project typically needs a Performance Solution involving fire engineering reports, AS 5113 facade fire testing, or both. That adds time, cost, and approval risk. A non-combustible aluminium facade system simplifies the compliance pathway - one less variable for the certifier and one less source of programme delay.

For sarking membranes behind the cladding, NCC C2D10(6)(f) addresses non-combustible facade assemblies specifically. When the cladding itself is non-combustible, the requirements for the sarking behind it are less onerous than when combustible cladding is used. Similarly, there is no Deemed-to-Satisfy requirement for cavity barriers within the ventilated space behind a non-combustible rainscreen on most facade configurations - though the project’s fire engineer and BCA consultant should always confirm the specific requirements for each building.

Why is curtain wall the primary system for office facades?

Office buildings are designed around daylight. The commercial real estate market values natural light, views, and transparency - these factors directly affect rental premiums and tenant satisfaction. Window-to-wall ratios on modern office buildings commonly sit between 50% and 80%, and sometimes higher on premium-grade towers.

At those glazing ratios, a curtain wall system is not optional - it is the only practical way to deliver a weathertight, structurally adequate glazed envelope at scale.

The 165CW unitised curtain wall system is designed and extruded in Australia for this type of application. The key specifications that matter on office projects:

165mm frame depth. Deep enough to accommodate high-performance insulated glass units (IGUs) from 24mm to 40mm, including double-glazed and triple-glazed configurations with low-E coatings and argon or krypton fill.
Thermally broken glazing adaptors. A polyamide strip with an aluminium nose cap separates the internal and external aluminium faces of the frame. This thermal break is critical for commercial buildings targeting Section J compliance and NABERS ratings - it reduces heat transfer through the frame itself, not just through the glass.
Unitised construction. Complete panels - one storey high by one bay wide - are assembled, glazed, sealed, and quality-checked in a factory before arriving on site. Panels hook onto 3-part structural brackets with 3D adjustment, and adjacent units interlock through gasket joints. Installation rates of twenty to forty panels per day compress facade programmes significantly compared to stick-built alternatives.
Stack head movement of plus or minus 25mm. Office buildings with long-span composite floor slabs deflect under live load and creep. The 165CW’s stack joint accommodates this movement without transferring load to the facade or compromising the weather seal.
Primary framing in 6060-T6 and structural members in 6005A-T6. These alloys provide the strength-to-weight ratio needed for wind load resistance on mid-rise and high-rise facades while keeping unit weights manageable for crane installation.

For estimation and fabrication, 165CW has a LogiKal software database developed specifically for the system. LogiKal handles estimating, cutting optimisation, AutoCAD export, and CNC machine control - this reduces the gap between design intent and fabricated output, particularly on large office projects with hundreds of curtain wall units.

What role do spandrel panels play on office facades?

Not every part of an office facade is vision glass. Between the glazed areas, spandrel zones conceal floor slabs, structural beams, services risers, and fire-rated construction between floors. These spandrel zones are where solid aluminium panels work within the curtain wall envelope.

element13 is a 3mm solid aluminium panel with PVDF paint finishes that provides an opaque, non-combustible panel behind the curtain wall glazing line. On office buildings, element13 spandrel panels typically:

Sit within the curtain wall framing in the same plane as the vision glass, creating a flush external appearance.
Provide the non-combustible backing required at floor-to-floor junctions where fire separation between storeys is needed. The slab-edge fire barrier (perimeter fire seal) sits behind the spandrel panel, closing the gap between the curtain wall and the slab edge.
Accept the same colour range as the building’s feature cladding elsewhere on the facade, maintaining a consistent material language.

element13 panels are available in standard stock colours - solids, metallics, and woodgrains - as well as custom colour matching for larger orders. The PVDF coating system meets AAMA 2605 for coating performance, delivering superior UV resistance and colour retention over the 20-year warranty period. On a corporate office building where the facade will be visible and assessed by tenants for decades, coating durability is not a minor detail.

Where do interloQ and conneQt fit on an office building?

Not every part of an office building facade is curtain wall. Most office projects include solid wall areas - plant rooms, service cores, stair enclosures, podium levels, car park screens, and architectural feature zones - where vision glazing is not required or not desirable.

interloQ is an interlocking aluminium rainscreen system that suits these conditions well. The panels install vertically or horizontally, interlock without exposed fixings, and create a drained and ventilated rainscreen cavity. On office projects, interloQ commonly appears on:

Plant room and services screening. Mechanical plant at roof level or intermediate floors needs screening that allows ventilation while presenting a finished appearance. interloQ panels can be spaced or perforated to provide airflow.
Podium and car park levels. The lower levels of office buildings often have different facade requirements - retail frontages, loading docks, car park ventilation - where a robust, low-maintenance cladding system is more appropriate than curtain wall.
Feature walls and accent zones. Different panel widths and orientations allow architects to create visual contrast against the curtain wall zones without introducing a different material system.

conneQt aluminium battens and adaptors play a specific role on office buildings: external solar shading. The 165CW curtain wall system includes purpose-designed horizontal and vertical sunshade brackets with a concealed nutplate connection. conneQt battens and fins attach directly to these brackets without penetrating the curtain wall weather line or compromising the thermal break.

This is worth understanding. On an office building where the north and west facades receive significant solar radiation, external shading is one of the most effective ways to reduce cooling loads. conneQt battens - installed horizontally on north-facing curtain wall or vertically on east and west elevations - intercept solar radiation before it reaches the glass. Because the shading is integrated into the curtain wall framing rather than bolted on as a separate structure, the coordination between trades is simpler, the thermal bridging risk is lower, and the whole assembly reads as one system.

How does Section J energy efficiency affect office facade design?

NCC Section J sets the energy efficiency requirements for commercial buildings, and the facade is where much of the compliance work happens. For office buildings, two provisions dominate the facade specification:

J1.5 - external walls. Wall assemblies must achieve minimum R-values based on climate zone. For curtain wall spandrel zones, this means insulated spandrel panels or insulated backing walls. For rainscreen cladding zones (interloQ on plant rooms and podiums), continuous rigid insulation behind the cladding provides the thermal resistance.

J1.6 - glazing. This is the provision that shapes most office facade decisions. Section J limits the thermal transmittance (U-value) and solar heat gain coefficient (SHGC) of glazing based on climate zone, orientation, and glazing area. On an office building with 60-80% window-to-wall ratio, the glazing specification essentially determines whether the building passes Section J.

165CW’s ability to accept IGUs from 24mm to 40mm gives the energy modeller the range needed to tune U-value and SHGC for each orientation. A north-facing elevation might use a 28mm double-glazed IGU with a high visible light transmittance and moderate SHGC, while a west-facing elevation uses a 36mm unit with a more aggressive solar control coating. The thermally broken frame reduces frame U-value, which matters more as glazing areas increase.

External shading via conneQt battens on 165CW sunshade brackets further reduces the effective SHGC by intercepting radiation before it reaches the glass. This is an increasingly common strategy on office projects - particularly on west-facing elevations - because it allows a less expensive or higher-transmittance glass to achieve the same overall solar performance. The shading does the thermal work, so the glass can prioritise daylight.

What about NABERS and Green Star on commercial offices?

Beyond NCC compliance, most institutional office buildings in Australia target a NABERS Energy rating. NABERS rates the actual energy performance of operating buildings on a scale of one to six stars, and prospective tenants use it as a benchmark. Premium and A-grade office buildings typically target 5 or 5.5 stars, which requires an envelope that genuinely performs - not one that barely passed Section J.

The facade contributes to NABERS outcomes through thermal performance (reducing heating and cooling demand), air tightness (unitised curtain wall systems achieve lower air infiltration rates than site-assembled alternatives), and solar control (reducing peak cooling loads on sun-exposed elevations).

Green Star, administered by the GBCA, assesses the building at design and construction stage. The facade affects credits across the Energy, Materials, and Indoor Environment Quality categories. Aluminium’s recyclability, long service life, and contribution to reduced operational energy all support Green Star submissions. The 100% recyclability of aluminium at end of life is a genuine lifecycle advantage that Green Star’s materials credits recognise.

How does Valmond & Gibson support office building projects?

V&G supplies the facade systems - 165CW curtain wall, element13 spandrel panels, interloQ cladding, and conneQt shading - as a coordinated product range from a single supplier. On an office building where three or four of these systems appear on the same facade, single-source supply simplifies procurement, reduces interface risk between different cladding systems, and provides one point of accountability for product documentation.

All four systems are non-combustible (CSIRO-tested to AS1530.1), supported by compliance packs and testing reports, and backed by up to 20-year warranties. 165CW is designed, engineered, and extruded in Australia, with a LogiKal software database for estimation through to CNC fabrication. Technical documentation, compliance packs, and project support are available for architects, facade engineers, and installers working on commercial office projects at any stage of design or procurement.

If you are specifying or tendering a commercial office facade and need product data, compliance documentation, or technical guidance on system selection, contact our team or download the 165CW product brochure.

Last updated: 4 April 2026

Aluminium Facades for Office Buildings