The precaster and our steel fabricator are pushing 10-inch hollow-core plank on a steel frame instead of the PT flat plate on the Alder Creek office building. Using the estimate export, Birchline's structural alternates memo and the precast, ready-mix and steel proposals, build an embodied carbon estimate (A1–A5, with trucking, jobsite waste and generic values where we don't have EPDs) and tell me whether we still meet the owner's target in Section 01 81 13. Show which combinations of structural system, concrete mix and cladding meet it and which don't, and include a reduced-carbon alternate.