Most carbon conversations begin far too late, usually when a certification consultant joins a project already under construction.
By then the structural grid is fixed, the cement content is specified and the meaningful choices are gone. What remains is procurement substitution at the margins.
The reductions that matter — thirty per cent and above — come from structural optimisation, from choosing a shorter span, from reusing a foundation, from simply building less.
That is a programme decision made in month two, not a material decision made in month twenty.