bim-qto

# BIM Quantity Takeoff

## Overview
Quantity Takeoff (QTO) extracts measurable quantities from BIM models. This skill processes BIM exports to generate grouped quantity reports for cost estimation.

## Python Implementation

```python
import pandas as pd
import numpy as np
from typing import Dict, Any, List, Optional, Tuple
from dataclasses import dataclass, field
from enum import Enum


class QTOUnit(Enum):
    """Quantity takeoff measurement units."""
    COUNT = "ea"
    LENGTH = "m"
    AREA = "m2"
    VOLUME = "m3"
    WEIGHT = "kg"
    LINEAR_FOOT = "lf"
    SQUARE_FOOT = "sf"
    CUBIC_YARD = "cy"


@dataclass
class QTOItem:
    """Single QTO line item."""
    category: str
    type_name: str
    description: str
    quantity: float
    unit: str
    level: Optional[str] = None
    material: Optional[str] = None
    element_count: int = 0


@dataclass
class QTOReport:
    """Complete QTO report."""
    project_name: str
    items: List[QTOItem]
    total_elements: int
    categories: int
    generated_date: str


class BIMQuantityTakeoff:
    """Extract quantities from BIM data."""

    # Column mappings for different BIM exports
    COLUMN_MAPPINGS = {
        'type': ['Type Name', 'TypeName', 'type_name', 'Family and Type', 'IfcType'],
        'category': ['Category', 'category', 'IfcClass', 'Element Category'],
        'level': ['Level', 'level', 'Building Storey', 'BuildingStorey', 'Floor'],
        'volume': ['Volume', 'volume', 'Volume (m³)', 'Qty_Volume'],
        'area': ['Area', 'area', 'Surface Area', 'Area (m²)', 'Qty_Area'],
        'length': ['Length', 'length', 'Length (m)', 'Qty_Length'],
        'count': ['Count', 'count', 'Quantity', 'ElementCount'],
        'material': ['Material', 'material', 'Structural Material', 'MaterialName']
    }

    def __init__(self, df: pd.DataFrame):
        """Initialize with BIM data DataFrame."""
        self.df = df
        self.column_map =...