BIM Visual Programming Automation

Overview

This skill provides visual programming scripts and Python nodes for automating BIM workflows. Extract data, modify elements in batch, generate schedules, and integrate with external systems.

> Note: Examples use Autodesk® Revit® and Dynamo™ APIs. Autodesk, Revit, and Dynamo are registered trademarks of Autodesk, Inc.

Key Capabilities:

• Batch element modification
• Data export/import
• Schedule generation
• Parameter management
• External data integration
• Automated QTO

Quick Start (Dynamo Python)

python
# Dynamo Python Script - Export all walls to Excel
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitServices')
from RevitServices.Persistence import DocumentManager
from Autodesk.Revit.DB import FilteredElementCollector, BuiltInCategory

doc = DocumentManager.Instance.CurrentDBDocument

# Get all walls
collector = FilteredElementCollector(doc)
walls = collector.OfCategory(BuiltInCategory.OST_Walls).WhereElementIsNotElementType().ToElements()

# Extract data
wall_data = []
for wall in walls:
    wall_data.append({
        'id': wall.Id.IntegerValue,
        'name': wall.Name,
        'length': wall.get_Parameter(BuiltInParameter.CURVE_ELEM_LENGTH).AsDouble() * 0.3048,
        'area': wall.get_Parameter(BuiltInParameter.HOST_AREA_COMPUTED).AsDouble() * 0.0929
    })

OUT = wall_data

Element Data Extraction

Comprehensive Element Extractor

python
# Dynamo Python Node - Extract all element data
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitServices')
clr.AddReference('RevitNodes')

from RevitServices.Persistence import DocumentManager
from Autodesk.Revit.DB import *
import Revit
clr.ImportExtensions(Revit.Elements)

doc = DocumentManager.Instance.CurrentDBDocument

def get_element_data(element):
    """Extract data from Revit element"""
    data = {
        'id': element.Id.IntegerValue,
        'category': element.Category.Name if element.Category else None,
        'name': element.Name,
        'level': None,
        'parameters': {}
    }

    # Get level
    level_param = element.get_Parameter(BuiltInParameter.SCHEDULE_LEVEL_PARAM)
    if level_param:
        level_id = level_param.AsElementId()
        if level_id.IntegerValue > 0:
            level = doc.GetElement(level_id)
            data['level'] = level.Name if level else None

    # Get all parameters
    for param in element.Parameters:
        try:
            if param.HasValue:
                if param.StorageType == StorageType.Double:
                    data['parameters'][param.Definition.Name] = param.AsDouble()
                elif param.StorageType == StorageType.Integer:
                    data['parameters'][param.Definition.Name] = param.AsInteger()
                elif param.StorageType == StorageType.String:
                    data['parameters'][param.Definition.Name] = param.AsString()
        except:
            pass

    return data

def extract_category(category_enum):
    """Extract all elements of a category"""
    collector = FilteredElementCollector(doc)
    elements = collector.OfCategory(category_enum).WhereElementIsNotElementType().ToElements()
    return [get_element_data(e) for e in elements]

# Extract structural elements
categories = [
    BuiltInCategory.OST_Walls,
    BuiltInCategory.OST_Floors,
    BuiltInCategory.OST_StructuralColumns,
    BuiltInCategory.OST_StructuralFraming,
    BuiltInCategory.OST_Doors,
    BuiltInCategory.OST_Windows
]

all_data = {}
for cat in categories:
    cat_name = cat.ToString().replace('OST_', '')
    all_data[cat_name] = extract_category(cat)

OUT = all_data

Quantity Take-Off Script

python
# Dynamo Python - QTO Export
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitServices')
from RevitServices.Persistence import DocumentManager
from Autodesk.Revit.DB import *

doc = DocumentManager.Instance.CurrentDBDocument

def get_qto_data():
    """Generate QTO data from model"""
    qto = {}

    # Walls
    walls = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_Walls)\
        .WhereElementIsNotElementType().ToElements()

    wall_qto = {}
    for wall in walls:
        wall_type = doc.GetElement(wall.GetTypeId())
        type_name = wall_type.get_Parameter(BuiltInParameter.ALL_MODEL_TYPE_NAME).AsString()

        if type_name not in wall_qto:
            wall_qto[type_name] = {'count': 0, 'area': 0, 'length': 0}

        wall_qto[type_name]['count'] += 1

        area_param = wall.get_Parameter(BuiltInParameter.HOST_AREA_COMPUTED)
        if area_param:
            wall_qto[type_name]['area'] += area_param.AsDouble() * 0.0929  # sqft to m2

        length_param = wall.get_Parameter(BuiltInParameter.CURVE_ELEM_LENGTH)
        if length_param:
            wall_qto[type_name]['length'] += length_param.AsDouble() * 0.3048  # ft to m

    qto['Walls'] = wall_qto

    # Floors
    floors = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_Floors)\
        .WhereElementIsNotElementType().ToElements()

    floor_qto = {}
    for floor in floors:
        floor_type = doc.GetElement(floor.GetTypeId())
        type_name = floor_type.get_Parameter(BuiltInParameter.ALL_MODEL_TYPE_NAME).AsString()

        if type_name not in floor_qto:
            floor_qto[type_name] = {'count': 0, 'area': 0, 'volume': 0}

        floor_qto[type_name]['count'] += 1

        area_param = floor.get_Parameter(BuiltInParameter.HOST_AREA_COMPUTED)
        if area_param:
            floor_qto[type_name]['area'] += area_param.AsDouble() * 0.0929

        vol_param = floor.get_Parameter(BuiltInParameter.HOST_VOLUME_COMPUTED)
        if vol_param:
            floor_qto[type_name]['volume'] += vol_param.AsDouble() * 0.0283  # cuft to m3

    qto['Floors'] = floor_qto

    return qto

OUT = get_qto_data()

Batch Modification

Batch Parameter Update

python
# Dynamo Python - Batch update parameters
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitServices')
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager
from Autodesk.Revit.DB import *

doc = DocumentManager.Instance.CurrentDBDocument

def batch_update_parameter(elements, param_name, values):
    """Update parameter for multiple elements"""
    TransactionManager.Instance.EnsureInTransaction(doc)

    results = []
    for elem, value in zip(elements, values):
        try:
            param = elem.LookupParameter(param_name)
            if param and not param.IsReadOnly:
                if param.StorageType == StorageType.String:
                    param.Set(str(value))
                elif param.StorageType == StorageType.Double:
                    param.Set(float(value))
                elif param.StorageType == StorageType.Integer:
                    param.Set(int(value))
                results.append(True)
            else:
                results.append(False)
        except Exception as e:
            results.append(str(e))

    TransactionManager.Instance.TransactionTaskDone()
    return results

# Input from Dynamo nodes
elements = IN[0]  # List of elements
param_name = IN[1]  # Parameter name (string)
values = IN[2]  # List of values

OUT = batch_update_parameter(elements, param_name, values)

Batch Copy Elements

python
# Dynamo Python - Copy elements to levels
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitServices')
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager
from Autodesk.Revit.DB import *
from System.Collections.Generic import List

doc = DocumentManager.Instance.CurrentDBDocument

def copy_to_levels(elements, target_levels):
    """Copy elements to multiple levels"""
    TransactionManager.Instance.EnsureInTransaction(doc)

    copied = []
    element_ids = List[ElementId]([e.Id for e in elements])

    for level in target_levels:
        # Calculate offset
        source_level = doc.GetElement(elements[0].LevelId)
        offset = XYZ(0, 0, level.Elevation - source_level.Elevation)

        # Copy
        new_ids = ElementTransformUtils.CopyElements(
            doc, element_ids, offset
        )

        copied.extend([doc.GetElement(id) for id in new_ids])

    TransactionManager.Instance.TransactionTaskDone()
    return copied

elements = IN[0]
target_levels = IN[1]

OUT = copy_to_levels(elements, target_levels)

Schedule Generation

Create Custom Schedule

python
# Dynamo Python - Create view schedule
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitServices')
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager
from Autodesk.Revit.DB import *

doc = DocumentManager.Instance.CurrentDBDocument

def create_wall_schedule(schedule_name):
    """Create a wall schedule with QTO fields"""
    TransactionManager.Instance.EnsureInTransaction(doc)

    # Create schedule
    schedule = ViewSchedule.CreateSchedule(
        doc,
        ElementId(BuiltInCategory.OST_Walls)
    )
    schedule.Name = schedule_name

    # Add fields
    definition = schedule.Definition
    schedulable = definition.GetSchedulableFields()

    # Find and add specific fields
    field_names = ['Type', 'Level', 'Length', 'Area', 'Volume']

    for sf in schedulable:
        if sf.GetName(doc) in field_names:
            definition.AddField(sf)

    # Add sorting/grouping
    type_field = None
    for field in definition.GetFieldOrder():
        if definition.GetField(field).GetName() == 'Type':
            type_field = field
            break

    if type_field:
        sorting = ScheduleSortGroupField(type_field, ScheduleSortOrder.Ascending)
        sorting.ShowHeader = True
        sorting.ShowFooter = True
        definition.AddSortGroupField(sorting)

    TransactionManager.Instance.TransactionTaskDone()
    return schedule

schedule_name = IN[0]
OUT = create_wall_schedule(schedule_name)

External Data Integration

Import Data from Excel

python
# Dynamo Python - Import Excel and update Revit
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitServices')
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager
from Autodesk.Revit.DB import *

# Requires Excel data as input from Dynamo Excel nodes
doc = DocumentManager.Instance.CurrentDBDocument

def update_from_excel(excel_data, id_column, param_columns):
    """Update Revit elements from Excel data"""
    TransactionManager.Instance.EnsureInTransaction(doc)

    results = []

    for row in excel_data:
        try:
            # Get element by ID
            elem_id = ElementId(int(row[id_column]))
            element = doc.GetElement(elem_id)

            if element:
                row_result = {'id': elem_id.IntegerValue, 'updates': {}}

                for col_name, col_index in param_columns.items():
                    param = element.LookupParameter(col_name)
                    if param and not param.IsReadOnly:
                        value = row[col_index]
                        if param.StorageType == StorageType.String:
                            param.Set(str(value))
                        elif param.StorageType == StorageType.Double:
                            param.Set(float(value))
                        row_result['updates'][col_name] = value

                results.append(row_result)
        except Exception as e:
            results.append({'error': str(e)})

    TransactionManager.Instance.TransactionTaskDone()
    return results

excel_data = IN[0]  # 2D list from Excel
id_column = IN[1]   # Column index for element ID
param_columns = IN[2]  # Dict: param_name -> column_index

OUT = update_from_excel(excel_data, id_column, param_columns)

Dynamo Package Workflow

Full QTO Pipeline (Dynamo Graph Nodes)

1. Categories (Input)
   |
2. All Elements of Category (Revit)
   |
3. Element.GetParameterValueByName (Multiple parameters)
   |
4. Python Script (Process and calculate)
   |
5. List.Transpose
   |
6. Data.ExportExcel
   |
7. File Path (Output)

Quick Reference

| Task | Method | Performance | |------|--------|-------------| | Get Elements | FilteredElementCollector | Fast | | Get Parameter | element.LookupParameter() | Fast | | Set Parameter | TransactionManager required | Moderate | | Copy Elements | ElementTransformUtils | Moderate | | Create Views | ViewSchedule.CreateSchedule | Slow | | Delete Elements | Document.Delete | Fast |

Common Parameter Names

python
# Built-in parameters for quantities
QUANTITY_PARAMS = {
    'Length': BuiltInParameter.CURVE_ELEM_LENGTH,
    'Area': BuiltInParameter.HOST_AREA_COMPUTED,
    'Volume': BuiltInParameter.HOST_VOLUME_COMPUTED,
    'Height': BuiltInParameter.WALL_USER_HEIGHT_PARAM,
    'Width': BuiltInParameter.DOOR_WIDTH,
    'Level': BuiltInParameter.SCHEDULE_LEVEL_PARAM
}

# Unit conversion (Imperial to Metric)
CONVERSIONS = {
    'feet_to_meters': 0.3048,
    'sqft_to_sqm': 0.0929,
    'cuft_to_cum': 0.0283
}

Resources

• Dynamo Primer: https://primer.dynamobim.org
• Revit API Docs: https://www.revitapidocs.com
• DDC Website: https://datadrivenconstruction.io

Next Steps

• See ifc-data-extraction for IFC export
• See qto-report for advanced quantity reports
• See n8n-workflow-automation for external integration