Window shrouds do two jobs at once. They shade the glass and they change how a building reads from the street. The material you pick decides how well the shroud does both, and for how long. Here's how aluminium, steel and other metal shrouds compare, and what to weigh before you commit to window shroud installation. A OK Brothers Constructions fabricates and installs shrouds in all three materials across Melbourne, and the trade-offs below reflect what actually plays out on site.
Aluminium window shrouds
Aluminium is the most common choice for window shrouds Melbourne wide, and there's a plain reason for that: it's light, it doesn't rust, and it takes powder coating well. A shroud that weighs less puts less load on the window frame and the wall fixings behind it, which matters on multi-storey builds where every bracket has to be engineered.
Aluminium also bends into curves and angles more easily than steel, so it suits architectural shapes - cantilevered hoods, angled fins, wrap-around cladding. Powder coating gives you colour options that hold up under Melbourne's UV exposure without fading or chalking within a few years.
The trade-off is stiffness. Aluminium flexes more than steel under the same load, so longer spans need thicker sections or extra bracing. On a large commercial façade that can push up material cost.
Steel window shrouds
Steel wins on raw strength. For long, unsupported spans or shrouds that need to carry extra weight - think integrated planter boxes, screens, or heavy sun-shading louvres - steel holds its shape with a thinner profile than aluminium would need.
The catch is corrosion. Untreated steel rusts, and once rust starts at a fixing point or a cut edge, it spreads. Galvanising or a proper powder coat system solves this, but it adds a step to fabrication and a cost to the quote. Steel shrouds also weigh more, which means the wall structure behind them needs to be checked before installation, not after.
For commercial and industrial buildings where the shroud is doing structural work as well as shading work, steel is often the right call. For a house renovation, it's usually overkill.
Other metal shrouds
Beyond aluminium and steel, some projects use zinc, copper or stainless steel for metal shrouds with a specific look or a specific durability requirement. Copper develops a patina over years, which some architects want and others actively avoid. Stainless steel resists corrosion without coating, which suits coastal-adjacent sites, but it costs more per square metre than either aluminium or mild steel. Zinc sits somewhere in between: a soft grey finish that weathers evenly, at a price point above standard aluminium.
None of these are common defaults. They show up on projects where the brief calls for a particular material finish, not just a functional shroud.
What actually decides the choice
Three things drive the decision on any given job:
Span and load. Short spans with light loads suit aluminium. Long spans or added weight suit steel.
Exposure. Coastal air, high UV, or heavy weather push the spec toward stainless steel or a well-coated aluminium or steel system.
Budget and maintenance appetite. Aluminium generally costs less upfront and needs less ongoing attention. Steel and specialty metals can cost more but last decades if the coating system is done properly.
The shape of the shroud matters too. Curved, angled, or highly custom profiles are easier and cheaper to achieve in aluminium. Straight structural runs are where steel earns its cost.
Getting the installation right
Material choice only pays off if the installation matches it. Fixings, flashing, and the gap between the shroud and the window frame all need to be right for the specific metal used - steel and aluminium expand and contract at different rates, and mixing metals without the correct isolation between them causes galvanic corrosion at the contact points. This is one of the more common defects seen on façades where the design was sound but the install cut corners.
For bespoke window shrouds Melbourne projects, working with a team that fabricates on site and understands the trade-offs between materials means the shroud gets specified correctly from the start, rather than adjusted after the fact.
A OK Brothers Constructions builds bespoke window shrouds across Melbourne, in aluminium, steel and other metals, sized and finished for the specific building. Full details on their window shrouds Melbourne page cover design options, finishes and the installation process.
Ready to talk shrouds
If you're planning window shrouds for a new build, renovation or façade upgrade, get the material spec right before fabrication starts. Contact A OK Brothers Constructions on 0435 816 315 (Sam) or 0403 526 479 (Abdul) or email info@aokbrothers.com.au.