RevitAPI – Getting parameters

In RevitAPI not all objects have exposed parameters as properties. Some basic level properties can be directly accessed using the getter (e.g. the element name, level name), but other elements are more complicated because they are not directly defined but they descend directly from a base class (FamilyInstance). Both windows and doors are familyinstances, the difference in the type of parameters they have and their category.

For these elements to access a parameter value you have to use the Element method “get_Parameter”.

Built In Parameter – n enumerated type listing all of the built-in parameter IDs supported by Autodesk Revit.

Element – Base class for most persistent data within a Revit document.

ElementId – The ElementId object is used as a unique identification for an element within a single project.

//room area
Parameter parameter = element.get_Parameter(BuiltInParameter.ROOM_AREA);
double area = (parameter.HasValue) ? parameter.AsDouble() : 0;
//room perimeter
Parameter parameter = element.get_Parameter(BuiltInParameter.ROOM_PERIMETER);
double perimeter = (parameter.HasValue) ? parameter.AsDouble() : 0;
//room phase
Parameter parameter = room.get_Parameter(BuiltInParameter.ROOM_PHASE);
ElementId phaseId = (parameter.HasValue) ? parameter.AsElementId() : null;
if (phaseId != null)
   Phase phase = Document.GetElement(phaseId) as Phase;
//room number
Parameter parameter = element.get_Parameter(BuiltInParameter.ROOM_NUMBER);
string roomNumber = (parameter.HasValue) ? parameter.AsString() : String.Empty;
//room occupancy
Parameter parameter = element.get_Parameter(BuiltInParameter.ROOM_OCCUPANCY);
string roomOccupancy = (parameter.HasValue) ? parameter.AsString() : String.Empty;
//room location
LocationPoint point = room.Location as LocationPoint
//room name
//Note : you can access also room.Name - but this property will compose the actual name with the number of the room
Parameter parameter = element.get_Parameter(BuiltInParameter.ROOM_NAME);
string roomName = (parameter.HasValue) ? parameter.AsString() : String.Empty;
//room department
Parameter parameter = element.get_Parameter(BuiltInParameter.ROOM_DEPARTMENT);
string roomDepartment = (parameter.HasValue) ? parameter.AsString() : String.Empty;
//door height
Parameter parameter = element.get_Parameter(BuiltInParameter.DOOR_HEIGHT);
double doorHeight = (parameter.HasValue) ? parameter.AsDouble() : 0;
//door width
Parameter parameter = element.get_Parameter(BuiltInParameter.DOOR_WIDTH);
double doorWidth = (parameter.HasValue) ? parameter.AsDouble() : 0;
//door mark
Parameter parameter = element.get_Parameter(BuiltInParameter.DOOR_NUMBER);
double doorMark = (parameter.HasValue) ? parameter.AsDouble() : 0;
//window height
Parameter parameter = element.get_Parameter(BuiltInParameter.WINDOW_HEIGHT);
double windowHeight = (parameter.HasValue) ? parameter.AsDouble() : 0;
//window width
Parameter parameter = element.get_Parameter(BuiltInParameter.WINDOW_WIDTH);
double windowWidth = (parameter.HasValue) ? parameter.AsDouble() : 0;
//Same enumeration value as for door is used for windows : 
Parameter parameter = element.get_Parameter(BuiltInParameter.DOOR_NUMBER);
double windowMark = (parameter.HasValue) ? parameter.AsDouble() : 0;
//Family instance comment
Parameter parameter = element.get_Parameter(BuiltInParameter.ALL_MODEL_INSTANCE_COMMENTS);
string comment = (parameter.HasValue) ? parameter.AsString() : String.Empty;