Revit Element And Parameter Access

Revit Element and Parameter Access

The Nice3point.Revit.Extensions accessors wrap the raw element and parameter API — document.GetElement(id) as T, raw different parameter getters, manual StorageType switching, and UnitUtils — into one fluent, nullable chain. FindParameter also falls back to the element type when the instance lacks the parameter.

When to use

• Finding an Element by ElementId.
• Reading or writing a parameter value, or converting a stored length to display units.

When not to use

• Finding a set of elements from the model — use revit-element-collector.

Workflow

Step 1: Get a typed element from an id

var wall = wallId.ToElement<Wall>(document);

Returns null when the element is missing or not that type.

Step 2: Find a parameter

var parameter = wall.FindParameter(BuiltInParameter.WALL_USER_HEIGHT_PARAM);

FindParameter accepts a BuiltInParameter, ParameterTypeId, Guid, or name, and returns the type's parameter when the instance has none. It returns null when the parameter is absent — null-check for optional parameters.

Step 3: Read the typed value

double heightFeet = parameter.AsDouble(); // native api call
bool isStructural = wall.FindParameter(BuiltInParameter.WALL_STRUCTURAL_SIGNIFICANT).AsBool();
Color color = door.FindParameter("Door color").AsColor();
Level level = wall.FindParameter(BuiltInParameter.WALL_BASE_CONSTRAINT).AsElement<Level>();

Step 4: Convert internal units at the boundary

Revit stores lengths in feet; convert when values leave or enter the model.

double heightMm = parameter.AsDouble().ToMillimeters();

Step 5: Write inside a transaction

parameter.Set(3.0.FromMeters());
door.FindParameter("Door color").Set(new Color(66, 69, 96));

Writes require an open transaction.

Validation

• ElementId is resolved with ToElement<T>, not GetElement(id) as T.
• Parameters are found with FindParameter, and optional ones are null-checked.
• Stored lengths are converted at the boundary with the unit conversion extensions.
• Writes happen inside a transaction.

Common Pitfalls