qto-report

Quantity Take-Off (QTO) Report Generation

Overview

Based on DDC methodology (Chapter 3.2), this skill automates the extraction and grouping of quantities from BIM/CAD data. QTO is the foundation for cost estimation, scheduling, and project planning in construction.

Book Reference: "Quantity Take-Off и автоматическое создание смет" / "QTO and Automated Estimates"

"QTO Quantity Take-Off: группировка данных по атрибутам позволяет автоматически извлекать объемы и количества из BIM-моделей для расчета стоимости." — DDC Book, Chapter 3.2

5D BIM Concept

The QTO process is central to 5D BIM:

• 3D: Geometry (volume, area, length)
• 4D: Time (schedule integration)
• 5D: Cost (quantity × unit price)

Quick Start

import pandas as pd

# Load BIM element data
df = pd.read_csv("revit_export.csv")

# Generate QTO by category
qto = df.groupby('Category').agg({
    'Volume': 'sum',
    'Area': 'sum',
    'ElementId': 'count'
}).rename(columns={'ElementId': 'Count'})

# Calculate cost (if unit prices available)
qto['Unit_Price'] = [150, 80, 450, 200]  # $/m³
qto['Total_Cost'] = qto['Volume'] * qto['Unit_Price']

qto.to_excel("qto_report.xlsx")

Core QTO Functions

Basic QTO by Category

import pandas as pd

def generate_qto(df, group_by='Category'):
    """
    Generate Quantity Take-Off grouped by specified column

    Args:
        df: DataFrame with BIM elements
        group_by: Column(s) to group by

    Returns:
        QTO summary DataFrame
    """
    # Define aggregations based on available columns
    agg_dict = {}

    if 'Volume' in df.columns:
        agg_dict['Volume'] = 'sum'
    if 'Area' in df.columns:
        agg_dict['Area'] = 'sum'
    if 'Length' in df.columns:
        agg_dict['Length'] = 'sum'
    if 'Count' in df.columns:
        agg_dict['Count'] = 'sum'
    else:
        agg_dict['ElementId'] = 'count'

    qto = df.groupby(group_by).agg(agg_dict)

    if 'ElementId' in agg_dict:
        qto = qto.rename(columns={'ElementId': 'Count'})

    return qto.round(2)

# Usage
qto = generate_qto(df, group_by='Category')
print(qto)