Every number can answer one question: "says who?"
Written for the people who check the numbers — architects, engineers, estimators. These are the three rules CAIRO is built on, and what each means for your liability.
Nothing is fabricated
A number appears in your takeoff only if it was extracted from the document set or follows from a rule you can inspect. If neither — the cell says awaiting input, in gold. A famous example from a real project: the drawings stated mirror height but nowhere the width. Your sheet shows exactly that.
Everything is traceable
Every extracted fact keeps its provenance: document, page, schedule row or plan region. Challenge any cell and it cites its source — the same way you would flip to sheet A-402 to settle an argument.
Everything is accounted for
Conservation: every piece of information found in the package is either placed in the takeoff, marked out-of-scope, or explicitly declared unknown. The three buckets must sum to the whole document — so nothing silently disappears.
Click a cell, get its source.
This is a real trace from a 178-unit residential package (identifying details removed). Note the last row: the honest gap is a feature, not an apology — it tells your estimator precisely what to verify before quoting.
No guessed dimensions
We never infer a missing size from "typical" values or similar projects. Typical is not yours.
No silent assumptions
Scope is confirmed by you before extraction counts against it. Nothing rides in on a default.
No black box
The sheet is a live spreadsheet with visible formulas — not a PDF verdict. Audit it cell by cell.