Most of the carbon conversation in glazing has focused on the glass itself: thinner panes, better coatings, more efficient units. The support system has been harder to decarbonise because it is structural and because nobody owns it. That is beginning to change.
The hybrid idea
The approach described here replaces the steel bracket on the majority of perimeter points with a hybrid aluminium-and-steel component, leaving full steel only where loads demand it. The result is less mass, fewer welds and a materially shorter section.
The engineering case is unremarkable in the best way: it is a geometry problem with an established solution space. The commercial case is more interesting, because the client — not the fabricator — ends up holding the carbon number.
What the early projects show
Three completed projects report a reduction in embodied carbon of between 31 and 38 per cent against an equivalent steel system, with no change to the visual result. Panel weights fell enough to reduce crane requirements on two of the three, which is where the schedule benefit came from.
Critically, the system is not a proprietary assembly. Any competent curtain wall fabricator can read the drawings and price it. That has done more for adoption than any technical advantage.
What could go wrong
Fire stopping at the slab edge remains the hardest detail, and it is the one that will decide whether the approach spreads beyond prestige projects. There is also a skills question: fitters who have spent twenty years around steel brackets need retraining, and that takes longer than the drawings do.
What to ask your supplier
Ask for the EPD of the support system, not just of the glass. Ask for the weld procedure qualification. And ask which third party has reviewed the slab-edge firestop, because in two years this will be a box-ticking question and the honest suppliers will already have the answer.
