Excel to BIM Update

Business Case

Problem Statement

After extracting BIM data to Excel and enriching it (cost codes, classifications, custom data):

• Changes need to flow back to the BIM model
• Manual re-entry is error-prone
• Updates must match by element ID

Solution

Push Excel data back to BIM models, updating element parameters and properties from spreadsheet changes.

Business Value

• Bi-directional workflow - BIM → Excel → BIM
• Bulk updates - Change thousands of parameters
• Data enrichment - Add classifications, codes, costs
• Consistency - Spreadsheet as single source of truth

Technical Implementation

Workflow

BIM Model (Revit/IFC) → Excel Export → Data Enrichment → Excel Update → BIM Model

Python Implementation

python
import pandas as pd
from pathlib import Path
from typing import Dict, Any, List, Optional, Tuple
from dataclasses import dataclass, field
from enum import Enum
import json


class UpdateType(Enum):
    """Type of BIM parameter update."""
    TEXT = "text"
    NUMBER = "number"
    BOOLEAN = "boolean"
    ELEMENT_ID = "element_id"


@dataclass
class ParameterMapping:
    """Mapping between Excel column and BIM parameter."""
    excel_column: str
    bim_parameter: str
    update_type: UpdateType
    transform: Optional[str] = None  # Optional transformation


@dataclass
class UpdateResult:
    """Result of single element update."""
    element_id: str
    parameters_updated: List[str]
    success: bool
    error: Optional[str] = None


@dataclass
class BatchUpdateResult:
    """Result of batch update operation."""
    total_elements: int
    updated: int
    failed: int
    skipped: int
    results: List[UpdateResult]


class ExcelToBIMUpdater:
    """Update BIM models from Excel data."""

    # Standard ID column names
    ID_COLUMNS = ['ElementId', 'GlobalId', 'GUID', 'Id', 'UniqueId']

    def __init__(self):
        self.mappings: List[ParameterMapping] = []

    def add_mapping(self, excel_col: str, bim_param: str,
                    update_type: UpdateType = UpdateType.TEXT):
        """Add column to parameter mapping."""
        self.mappings.append(ParameterMapping(
            excel_column=excel_col,
            bim_parameter=bim_param,
            update_type=update_type
        ))

    def load_excel(self, file_path: str,
                   sheet_name: str = None) -> pd.DataFrame:
        """Load Excel data for update."""
        if sheet_name:
            return pd.read_excel(file_path, sheet_name=sheet_name)
        return pd.read_excel(file_path)

    def detect_id_column(self, df: pd.DataFrame) -> Optional[str]:
        """Detect element ID column in DataFrame."""
        for col in self.ID_COLUMNS:
            if col in df.columns:
                return col
            # Case-insensitive check
            for df_col in df.columns:
                if df_col.lower() == col.lower():
                    return df_col
        return None

    def prepare_updates(self, df: pd.DataFrame,
                        id_column: str = None) -> List[Dict[str, Any]]:
        """Prepare update instructions from DataFrame."""

        if id_column is None:
            id_column = self.detect_id_column(df)
            if id_column is None:
                raise ValueError("Cannot detect ID column")

        updates = []

        for _, row in df.iterrows():
            element_id = str(row[id_column])

            params = {}
            for mapping in self.mappings:
                if mapping.excel_column in df.columns:
                    value = row[mapping.excel_column]

                    # Convert value based on type
                    if mapping.update_type == UpdateType.NUMBER:
                        value = float(value) if pd.notna(value) else 0
                    elif mapping.update_type == UpdateType.BOOLEAN:
                        value = bool(value) if pd.notna(value) else False
                    elif mapping.update_type == UpdateType.TEXT:
                        value = str(value) if pd.notna(value) else ""

                    params[mapping.bim_parameter] = value

            if params:
                updates.append({
                    'element_id': element_id,
                    'parameters': params
                })

        return updates

    def generate_dynamo_script(self, updates: List[Dict],
                               output_path: str) -> str:
        """Generate Dynamo script for Revit updates."""

        # Generate Python code for Dynamo
        script = '''
# Dynamo Python Script for Revit Parameter Updates
# Generated by DDC Excel-to-BIM

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

# Update data
updates = '''
        script += json.dumps(updates, indent=2)
        script += '''

# Apply updates
TransactionManager.Instance.EnsureInTransaction(doc)

results = []
for update in updates:
    try:
        element_id = int(update['element_id'])
        element = doc.GetElement(ElementId(element_id))

        if element:
            for param_name, value in update['parameters'].items():
                param = element.LookupParameter(param_name)
                if param and not param.IsReadOnly:
                    if isinstance(value, (int, float)):
                        param.Set(float(value))
                    elif isinstance(value, bool):
                        param.Set(1 if value else 0)
                    else:
                        param.Set(str(value))
            results.append({'id': element_id, 'status': 'success'})
        else:
            results.append({'id': element_id, 'status': 'not found'})
    except Exception as e:
        results.append({'id': update['element_id'], 'status': str(e)})

TransactionManager.Instance.TransactionTaskDone()

OUT = results
'''

        with open(output_path, 'w') as f:
            f.write(script)

        return output_path

    def generate_ifc_updates(self, updates: List[Dict],
                             original_ifc: str,
                             output_ifc: str) -> str:
        """Generate updated IFC file (requires IfcOpenShell)."""

        try:
            import ifcopenshell
        except ImportError:
            raise ImportError("IfcOpenShell required for IFC updates")

        ifc = ifcopenshell.open(original_ifc)

        for update in updates:
            guid = update['element_id']

            # Find element by GUID
            element = ifc.by_guid(guid)
            if not element:
                continue

            # Update properties
            for param_name, value in update['parameters'].items():
                # This is simplified - actual IFC property handling is more complex
                # Would need to find/create property sets and properties
                pass

        ifc.write(output_ifc)
        return output_ifc

    def generate_update_report(self, original_df: pd.DataFrame,
                               updates: List[Dict],
                               output_path: str) -> str:
        """Generate report of planned updates."""

        report_data = []
        for update in updates:
            for param, value in update['parameters'].items():
                report_data.append({
                    'element_id': update['element_id'],
                    'parameter': param,
                    'new_value': value
                })

        report_df = pd.DataFrame(report_data)
        report_df.to_excel(output_path, index=False)
        return output_path


class RevitExcelUpdater(ExcelToBIMUpdater):
    """Specialized updater for Revit via ImportExcelToRevit."""

    def __init__(self, tool_path: str = "ImportExcelToRevit.exe"):
        super().__init__()
        self.tool_path = Path(tool_path)

    def update_revit(self, excel_file: str,
                     rvt_file: str,
                     sheet_name: str = "Elements") -> BatchUpdateResult:
        """Update Revit file from Excel using CLI tool."""

        import subprocess

        # This assumes ImportExcelToRevit CLI tool
        cmd = [
            str(self.tool_path),
            rvt_file,
            excel_file,
            sheet_name
        ]

        result = subprocess.run(cmd, capture_output=True, text=True)

        # Parse results (format depends on tool output)
        if result.returncode == 0:
            return BatchUpdateResult(
                total_elements=0,  # Would parse from output
                updated=0,
                failed=0,
                skipped=0,
                results=[]
            )
        else:
            raise RuntimeError(f"Update failed: {result.stderr}")


class DataEnrichmentWorkflow:
    """Complete workflow for data enrichment and update."""

    def __init__(self):
        self.updater = ExcelToBIMUpdater()

    def enrich_and_update(self, original_excel: str,
                          enrichment_excel: str,
                          merge_column: str) -> pd.DataFrame:
        """Merge enrichment data with original export."""

        original = pd.read_excel(original_excel)
        enrichment = pd.read_excel(enrichment_excel)

        # Merge on specified column
        merged = original.merge(enrichment, on=merge_column, how='left',
                                suffixes=('', '_enriched'))

        return merged

    def create_classification_mapping(self, df: pd.DataFrame,
                                      type_column: str,
                                      classification_file: str) -> pd.DataFrame:
        """Map BIM types to classification codes."""

        classifications = pd.read_excel(classification_file)

        # Fuzzy matching could be added here
        merged = df.merge(classifications,
                          left_on=type_column,
                          right_on='type_description',
                          how='left')

        return merged

Quick Start

python
# Initialize updater
updater = ExcelToBIMUpdater()

# Define mappings
updater.add_mapping('Classification_Code', 'OmniClassCode', UpdateType.TEXT)
updater.add_mapping('Unit_Cost', 'Cost', UpdateType.NUMBER)

# Load enriched Excel
df = updater.load_excel("enriched_model.xlsx")

# Prepare updates
updates = updater.prepare_updates(df)
print(f"Prepared {len(updates)} updates")

# Generate Dynamo script for Revit
updater.generate_dynamo_script(updates, "update_parameters.py")

Common Use Cases

1. Add Classification Codes

python
updater = ExcelToBIMUpdater()
updater.add_mapping('Omniclass', 'OmniClass_Number', UpdateType.TEXT)
updater.add_mapping('Uniclass', 'Uniclass_Code', UpdateType.TEXT)

df = updater.load_excel("classified_elements.xlsx")
updates = updater.prepare_updates(df)

2. Cost Data Integration

python
updater.add_mapping('Material_Cost', 'Pset_MaterialCost', UpdateType.NUMBER)
updater.add_mapping('Labor_Cost', 'Pset_LaborCost', UpdateType.NUMBER)

3. Generate Update Report

python
report = updater.generate_update_report(df, updates, "planned_updates.xlsx")

Integration with DDC Pipeline

python
# Full round-trip: Revit → Excel → Enrich → Update → Revit

# 1. Export from Revit
# RvtExporter.exe model.rvt complete

# 2. Enrich in Python/Excel
df = pd.read_excel("model.xlsx")
# Add classifications, costs, etc.
df['OmniClass'] = df['Type Name'].map(classification_dict)
df.to_excel("enriched_model.xlsx")

# 3. Generate update script
updater = ExcelToBIMUpdater()
updater.add_mapping('OmniClass', 'OmniClass_Number')
updates = updater.prepare_updates(df)
updater.generate_dynamo_script(updates, "apply_updates.py")

# 4. Run in Dynamo to update Revit

Resources

• GitHub: DDC Update Revit from Excel
• DDC Book: Chapter 2.4 - Bidirectional Data Flow