The architectural permit set isn't the input to the build pipeline — a hand-curated JSON ledger is. Every dimension and topology fact gets typed up by a human, each entry citing the sheet it came from. The ledger drives the model.
A validator then re-measures the Blender model against the ledger and reports pass, fail, or soft for every assertion, within a 0.125-inch tolerance. If the model drifts, the test fails; if the ledger has the wrong value, the test still fails, and you go back to the PDF to verify the human extraction.
Two distinct trust gates — human-to-ledger and ledger-to-model — instead of trying to verify everything at once.