Our 50mm Thermally Broken Windows — Residential Fixed and Awning
This is the system holding the best energy figures we can supply, full stop. It's also a range where we publish a gap most product pages would hide — because an unresolved wind rating is something you need to know before specifying, not after.
What it is and where we use it
Our 50mm residential thermally broken range covers fixed lites and awning sashes, plus casement sashes, awning-over-awning, high-lite and down-lite arrangements, transoms and mullions. It's the residential thermally broken option — the step we take when an energy report sets a U-value no standard system can reach, or when a mostly-glass room makes the frame's share of the wall matter. Most Melbourne homes don't need it, and we say so; when yours does, this is the range.
Energy performance — the lowest U-values we supply
The lowest certified whole-window U-value we can supply is 1.4 — this system's fixed lite with a 4mm LightBridge / 12mm 90 per cent argon / 4mm ClearEnergyTech unit on a warm-edge spacer. The awning reaches 1.8 with the same unit.
Holding the glass identical, this frame improves on our standard Comet by 1.0 to 1.1 on an awning and 0.5 on a fixed lite — the break earns roughly twice as much on an opening sash. Every one of our eight lowest thermally broken results uses a warm-edge spacer; the best aluminium-spacer result is 1.7, so warm edge is where we'd point any job chasing the floor.
Glazing options
Double glazed units of 20, 24 or 26mm — and double glazed only. Every one of the 272 certified residential ratings we hold for our thermally broken systems is a double glazed unit; single glazing isn't offered because it would fix the small problem and leave the large one.
Wind rating and tested performance — an honest gap
We don't have a verified wind class for this system, and we specifically will not guess one. The AS 2047 test report we hold for the 50mm thermally broken awning records an ultimate pressure of 1400 Pa but states no wind class at all — an empty cell means absent data, not a low result. Separately, the manufacturer's 2026 residential catalogue prints N2 for the thermally broken range against different pressures, and neither reconciles with our thermally broken awning-over-fixed test report, which achieved N4 general and N3 corner. Publishing any of the three as this system's rating would be wrong. We're resolving it with the manufacturer — if your project needs a certified N class on a 50mm thermally broken window, talk to us before it's specified.
Sizes and configurations
Fixed lites and awning/casement sashes with transom and mullion assemblies. We hold no stated maximum sizes for this system, and these units are double glazed only — which means heavy — so we size any large sash against the stay hardware before quoting.
What we'd recommend it for
Selectively, guided by your energy report: the awnings, casements and doors are where the thermal break earns roughly twice its keep, while a large fixed picture window in a standard frame with a good double glazed unit gets close to the thermally broken result on its own. If targets are set per item, usually only the items that miss need this range.