Datum reads the project base point, the survey point and the internal origin of the host model and of every loaded link, compares them against the model you name as the truth — the alpha — and turns every mismatch into a card that names the fix: what is wrong, which model to act on, which native Revit tool to use, and why it matters. It never touches your coordinates; the fix is always yours, the Revit way.
A mis-set survey point looks fine on screen for months — until the structural model lands a storey out in section, or the IFC export puts the site in the wrong country. The evidence is scattered across three invisible points in every model, and Revit never lines them up for you.
No setup, no scan button. Datum reads on open, judges against the alpha you choose, and hands you the evidence in the order you would ask for it.
Datum opens from the Setup panel and reads the host and every loaded link before you ask. The verdict is one line at the top — errors, warnings, info, and how many links share the alpha's coordinate system. The Alpha dropdown is the only decision you make: crown the model that owns the coordinate truth — usually the georeferenced civil or site model — and everything re-judges against it instantly, without re-reading.
| MODEL | ROLE | SHARED | GEO SYSTEM | UNITS | PBP (E,N,Z mm) | SURVEY PT (E,N,Z mm) | PBP→ORIGIN | N ANGLE | DIST ORIGIN | PINNED |
|---|---|---|---|---|---|---|---|---|---|---|
| Marina Tower — Block A | Host | Yes | BritishNatGrid | Millimeters | 0, 0, 0 | -31200, 24800, -1500 | 0 mm | 14.7° | 86.2 m | — |
| MT-Civil-Site.rvt | Link | Yes | BritishNatGrid | Millimeters | 0, 0, 0 | 0, 0, 0 | 0 mm | 14.7° | 12.4 m | Yes |
| MT-STR-Block A.rvt | Link | Yes | BritishNatGrid | Millimeters | 0, 0, 0 | -31200, 24800, -1500 | 0 mm | 14.7° | 86.2 m | No |
| MT-Site-Survey.rvt | Link | No | IrishGrid | Millimeters | 0, 0, 0 | 0, 0, 0 | 0 mm | 0° | 3.1 m | Yes |
| MT-MEP-Block A.rvt | Link (unloaded) | — | — | — | — | — | — | — | — | Yes |
The Coordinates table gives one row per model: shared coordinates yes or no, the geographic system, the units, the project base point and survey point in E,N,Z millimetres, the distance to the internal origin, true-north angle, and whether the link is pinned. An unloaded link keeps only its pin state — everything else is a dash, never a stale number. This is the table you quote verbatim in the coordination minute: the coordinate cells select and copy, and the Copy button takes the whole table.
| MODEL | ROLE | SHARED | GEO SYSTEM | UNITS | PBP (E,N,Z mm) | SURVEY PT (E,N,Z mm) | PBP→ORIGIN | N ANGLE | DIST ORIGIN | PINNED |
|---|---|---|---|---|---|---|---|---|---|---|
| Marina Tower — Block A | Host | Yes | BritishNatGrid | Millimeters | 0, 0, 0 | -31200, 24800, -1500 | 0 mm | 14.7° | 86.2 m | — |
| MT-Civil-Site.rvt | Link | Yes | BritishNatGrid | Millimeters | 0, 0, 0 | 0, 0, 0 | 0 mm | 14.7° | 12.4 m | Yes |
| MT-STR-Block A.rvt | Link | Yes | BritishNatGrid | Millimeters | 0, 0, 0 | -31200, 24800, -1500 | 0 mm | 14.7° | 86.2 m | No |
| MT-Site-Survey.rvt | Link | No | IrishGrid | Millimeters | 0, 0, 0 | 0, 0, 0 | 0 mm | 0° | 3.1 m | Yes |
| MT-MEP-Block A.rvt | Link (unloaded) | — | — | — | — | — | — | — | — | Yes |
The coordination matrix judges every link against the alpha on the three questions that decide a federation: does it share the coordinate system, does true north agree, is it georeferenced. Passes are shown as deliberately as failures, so “checked and OK” never looks like “not checked” — and an unloaded link scores a dash on every column, because a model Datum could not read can never masquerade as a pass.
| MODEL | SHARES SYSTEM | TRUE NORTH | GEOREFERENCED |
|---|---|---|---|
| MT-Civil-Site.rvt (alpha) | ✓ | – | ✓ |
| MT-STR-Block A.rvt | ✓ | ✓ | ✓ |
| MT-Site-Survey.rvt | ✗ | – | ✗ |
| MT-MEP-Block A.rvt | – | – | – |
Every finding is a card with a stable code and a severity, grouped under the model it belongs to. WHAT states the measured fact. WHERE names the model to act on. TOOL gives the exact native path — Manage > Coordinates > Acquire Coordinates, not “fix your coordinates”. WHY says what it costs you if you don't. Show where selects the flagged link or drops a temporary marker at the point, and every marker cleans itself up on Re-read or close. Datum detects and explains; it never silently fixes.
D016Link is on a different geographic coordinate systemErrorMT-Site-Survey.rvt is on coordinate system "IrishGrid" but the alpha model MT-Civil-Site.rvt is on "BritishNatGrid".
Act on the link (MT-Site-Survey.rvt) — or agree one project CRS.
Manage > Coordinates > Acquire Coordinates so all models share one geographic coordinate system; do not mix EPSG zones.
Shared coordinates only align models on the SAME geographic system. Two different CRS put models kilometres apart on export and in GIS even when both claim to be georeferenced.
Nineteen stable codes run on every audit. Nine compare each link with the alpha — shared system, placement rotation, project units, CRS, pinning, vertical datum, nested links, the same link inserted twice. Eleven judge each model on its own, host included: base point against the internal origin, grid anchoring, modelling quadrant, distance from origin, spare project positions. Findings group under the model that owns them, worst severity first, and the link nobody loaded is listed as D000 rather than quietly dropped.
D000Linked model not loaded — not assessedInfoMT-MEP-Block A.rvt is not loaded, so its coordinates could not be read or checked.
Load the link to assess it.
Manage > Manage Links > reload the model, then re-run Datum.
D001Link does not share the alpha model's coordinate systemWarningThe alpha model MT-Civil-Site.rvt is georeferenced (shared coordinates), but MT-Site-Survey.rvt is not. They are not on the same coordinate system.
Act on the link (MT-Site-Survey.rvt).
Manage > Coordinates > Acquire Coordinates from the alpha model so the link adopts the same shared coordinate system.
D013Model has no shared coordinates (not georeferenced)InfoMT-Site-Survey.rvt has no shared-coordinate position; the model is not tied to a survey / real-world datum.
Act on the link (MT-Site-Survey.rvt) if real-world coordinates are expected.
Manage > Coordinates > Specify Coordinates at Point, or Acquire Coordinates from a georeferenced model — the Survey Point stays at the internal origin; only its shared position changes.
D017Linked model is not pinnedWarningMT-STR-Block A.rvt is not pinned, so it can be dragged or nudged out of position by accident.
Act on the link (MT-STR-Block A.rvt).
Select the link instance and press Pin (Modify > Pin), or right-click > Pin. Pin every link after positioning.
The World Map plots the survey point, base point and internal origin of every model on a real map — three colour-coded markers per model, all carrying its number. A coordinated federation clusters on the site; a wrong coordinate system lands a model in another county — visibly, unarguably. Datum auto-detects the projection when the model exposes it; when it can't, it asks you for the project EPSG rather than guess.
One click writes a self-contained HTML report — the verdict, the searchable findings, the coordinates table and the matrix — that renders identically on a locked-down site-office laptop, because it carries no external dependencies. CSV and Copy serve the spreadsheet crowd, and Log opens the Datum log folder when someone asks how a number was measured.
Nine acceptance thresholds decide every verdict, and they live in a plain key=value file in your local profile: 1 mm from the internal origin, 0.01° of rotation, 50 mm to a grid intersection, 10 mm of vertical datum, and the precision limits — a warning past 10 km from the internal origin, an error past 32 km, near where Revit refuses to place elements at all. Align them with the BEP once; every exported report then states the tolerances it ran under.
Select a linked model anywhere in the project and Lens shows a DATUM card carrying that link's own findings: the severity word, the headline, the rule code as a trailing pill, and the long explanation behind a Details toggle. Ordinary elements cost nothing — the seam checks for a link instance first and returns immediately, so selecting a wall never triggers a model read. Each audit also publishes its headline to the Hub tile, which on its own reports Links loaded, Unpinned links and, when it can read them, Shared coordinates as Yes or Not detected.
When nothing is wrong the verdict turns green and names the model it was measured against, and the findings block states what was examined instead of showing nothing: base point, survey point, model quadrant, grid anchoring, units, georeferencing and every link. The measured table stays one click away, because the numbers are the deliverable whether or not anything failed. Nothing re-runs by itself — Re-read is the deliberate gesture, and it sweeps the temporary markers on its way.
This is an actual HTML report Datum exports — self-contained, works offline, shareable as one file. Scroll it right here, or open it full-screen.
Datum sits on the Setup panel of the BIMIO tab. Open it when you assemble the federation and before every export — coordinate problems are cheapest the day they are made. Revit 2024–2027, full trial, no card.