This is a great question! Our firm is proceeding with the policy: Only include items we designed. A full LCA will require each discipline to contribute.
But how about CMU? Say a steel office building with a CMU facade. Us engineers specify the f’m, but it’s not technically structuarl, and we don’t model the walls in our revit models.
Is the CMU part of the “structural system LCA”? Will engineers reporting to SE 2050 include the CMU-based emissions? CMU impact can be significant.
Important to be consistent for establishing benchmarks.