Levels

Levels are datums in the Revit model that define building storeys. In DAQS, they appear as objects in the flat array and are referenced by FamilyInstance objects via values.levelId.

---

The Level object

{
  "id": 311,
  "type": "Level",
  "name": "00 begane grond",
  "parent": null,
  "values": {
    "elevation": 0.0
  }
}

---

How instances reference levels

A FamilyInstance stores the level it is placed on as a numeric ID:

{
  "id": 616521,
  "type": "FamilyInstance",
  "values": {
    "levelId": 311
  }
}

This levelId corresponds to the id of a Level object in the same dataset.

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Resolving level name from instance

To include the level name in the filter output, look up the Level object by the instance's levelId:

(
  $levelIndex := $merge(
    $[type = "Level"].{ $string(id): name }
  );

  $[type = "FamilyInstance"].{
    "id": id,
    "name": name,
    "levelId": values.levelId,
    "levelName": $lookup($levelIndex, $string(values.levelId))
  }
)

The $levelIndex maps level IDs to level names. Each instance can then resolve its level name for display in error messages.

---

Filtering instances by level

To restrict a rule to instances on a specific level:

(
  $targetLevelId := $[type = "Level" and name = "00 begane grond"].id;

  $[type = "FamilyInstance" and values.levelId = $targetLevelId].{
    "id": id,
    "name": name
  }
)

Use the level id for linking — not the name, which can be renamed.

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Common mistakes

• Comparing values.levelId directly to a level name — levelId is a number, not a string
• Assuming levelId exists on all instances — some elements (like model groups) may not have one