> ## Documentation Index
> Fetch the complete documentation index at: https://docs.speckle.systems/llms.txt
> Use this file to discover all available pages before exploring further.

# Upgrade Revit to 2026.9

> Re-publish once, and switch scripts from root referencePointTransform to bundle modelPlacement.

<Note>
  This is 2026.9 preview documentation. Coverage here is incremental: a page exists only where
  2026.9 differs or is newly documented.
</Note>

This page is the mechanical path onto 2026.9 model placement. For Apply Transform, the placement
picker, and the placement record, see [Revit in
2026.9](/next/connectors/revit/introduction). For install, sign-in, publish, and load in today's connector,
see [How to use Speckle for Revit](/connectors/revit/revit).

## When to switch

Existing v3 models keep working. Re-publish from a 2026.9 connector if you need the viewer placement
picker and named datums. Scripts and SDK consumers that read `referencePointTransform` on the root
object must switch to `modelPlacement.*`.

## Before and after

| Before                                           | After                                        |
| ------------------------------------------------ | -------------------------------------------- |
| Geometry rewritten so the chosen datum is origin | Geometry stays in Revit internal coordinates |
| Root `referencePointTransform`                   | Bundle `modelPlacement.*` on `eav.model`     |
| Datum kind not recorded                          | Named datum plus `options.*` for every datum |
| One publish per consumer datum                   | One publish; consumers pick the datum        |

v3 connectors that read 2026.9 models get the old root-object transform rebuilt from the placement
record. When a 2026.9 consumer reads a v3 model, the old root transform is migrated into a placement
record, but the datum kind cannot be recovered.

## How to switch

<Steps>
  <Step title="Update the Revit connector">
    Use a 2026.9 Revit connector. You should see **Apply Transform** next to **Reference Point** in
    publish settings.
  </Step>

  <Step title="Publish a new version">
    Leave **Apply Transform** off, then publish as usual. You should see a new version on the model.
  </Step>
</Steps>

Keep **Apply Transform** off unless a downstream tool that does not understand model placements
needs the geometry pre-positioned.

### Scripts and SDK consumers

Assume the model is already in scope.

1. Read `modelPlacement.*` from `eav.model`.
2. Apply `modelPlacement.transform`. The value is 16 row-major doubles. Translation is expressed in
   `modelPlacement.units`.
3. If `modelPlacement.appliedToGeometry` is `true`, invert that transform before you place the
   model. Do this regardless of the receive datum.
4. Then apply the receive datum you want, if it is not **Source**.

AutoCAD and Civil 3D follow the same contract.

## FAQ

<AccordionGroup>
  <Accordion title="Where did referencePointTransform go?">
    It is not the placement record in 2026.9. Read `modelPlacement.*` from `eav.model`. See
    [Placement record](/next/connectors/revit/introduction#placement-record).
  </Accordion>

  <Accordion title="What happens if appliedToGeometry is true?">
    Invert `modelPlacement.transform` before you place the model, then apply your receive datum.
    Revit does this automatically. A custom consumer must do the same.
  </Accordion>

  <Accordion title="Do existing v3 models break?">
    No. They keep working. 2026.9 consumers rebuild a placement record from the old root transform.
    Re-publish once from a 2026.9 connector if you need the viewer placement picker and named
    datums.
  </Accordion>

  <Accordion title="Something still lands in the wrong place. What should I send?">
    Report it with the model URL and the publish and receive settings on both sides. The viewer's
    placement overlay shows world origin, model origin, and each reference point.
  </Accordion>
</AccordionGroup>