Comparison

uPVC vs Thermally Broken Aluminium Windows

Both are a big step up from the single glazed aluminium most Sydney unit blocks still have. We supply and install both, and this is how we help committees choose between them.

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Since 2011Sydney Strata Projects

uPVC & AluThermally Broken Systems

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In-HouseInstallation Team

Strata committees usually come to us with one question: uPVC or aluminium? Both systems take double glazing, both seal far better than the original windows, and either can be installed in an occupied building. The right answer depends on what the building needs most: the best possible insulation and noise reduction, or a facade that looks the way it always has.

When uPVC is the better choice

Choose uPVC when comfort and energy use come first: buildings on main roads or under flight paths, west-facing units that cook in summer, south-facing units that never warm up, and coastal blocks where aluminium corrodes. It is also the frame we use for Passive House work, because it insulates better than any aluminium system.

When thermally broken aluminium is the better choice

Choose thermally broken aluminium when the building needs to keep its original look, when the openings are very large, or when a taller building faces high wind loads. It is also a good fit where by-laws or a heritage consideration call for slim metal frames.

Mixing systems in one building

Some buildings use both: uPVC windows in bedrooms and living areas for insulation and noise, and thermally broken aluminium for wide balcony doors. As long as colours and sightlines are coordinated, the facade still reads as one. We price both options side by side in the proposal so the committee can compare like for like.

Side by side

uPVC vs Thermally Broken Aluminium

	uPVC (multi-chamber)	Thermally broken aluminium
Thermal performance	Best frame insulation - frame U-values as low as 0.77 W/m²K	Much better than standard aluminium; the frame still conducts more heat than uPVC
Noise reduction	Up to 45dB with acoustic laminated glass and a compression seal	Strong with acoustic glass; results depend on the seal design of the system
Condensation on frames	Minimal - the frame stays close to room temperature	Greatly reduced compared to standard aluminium
Appearance	Slightly wider frames; white, colours and woodgrain foils	Slim sightlines; powder coat in almost any colour; closest match to an original aluminium facade
Large openings and high-rise	Steel-reinforced profiles handle most residential openings	Suits very wide doors and high wind-load elevations
Coastal exposure	Does not corrode in salt air	Needs a suitable coastal-grade finish and regular washing
Approval	A change of frame material may need committee or owner approval	Like-for-like appearance can make approval simpler

Common questions

Questions from committees and owners

uPVC frames usually insulate better because the material itself conducts very little heat and the profile is divided into several air chambers. Thermally broken aluminium closes much of the gap compared to standard aluminium. With the same double glazed unit in both, the difference comes down to the frame.

Both have long service lives when they are specified and installed properly. uPVC does not corrode or need repainting. Aluminium is very durable but near the coast needs a suitable finish and regular washing to protect it.

Yes. Frame material is a matter for the owners corporation and any relevant by-laws or development consent, not a blanket rule. Where a change of material alters the appearance of the building, the committee may need owner approval at a general meeting, and we supply the product information to support that.

Yes. We supply and install both systems, so our proposals can price uPVC and thermally broken aluminium side by side for the same building.