AgentSkillsCN

co2-estimation

计算建筑项目的碳足迹,利用排放因子数据库,估算材料、运输与施工过程中的二氧化碳排放量。

SKILL.md
--- frontmatter
name: co2-estimation
description: "Calculate carbon footprint of construction projects. Estimate CO2 emissions from materials, transportation, and construction processes using emission factors databases."

CO2 Estimation for Construction

Overview

Based on DDC methodology (Chapter 3.3), this skill provides comprehensive CO2 and carbon footprint calculations for construction projects. Sustainability is no longer optional - clients and regulations demand accurate environmental impact assessments.

Book Reference: "4D, 6D-8D и расчет CO2" / "4D-8D BIM and CO2 Calculation"

"Расчет углеродного следа становится обязательным требованием для многих проектов. BIM-модель содержит все необходимые данные для автоматизации этого процесса." — DDC Book, Chapter 3.3

Quick Start

python
import pandas as pd

# Load BIM elements with materials
df = pd.read_excel("bim_elements.xlsx")

# CO2 emission factors (kg CO2 per unit)
emission_factors = {
    'Concrete': 0.13,      # kg CO2 per kg
    'Steel': 1.85,         # kg CO2 per kg
    'Brick': 0.24,         # kg CO2 per kg
    'Timber': -1.6,        # negative = carbon sink
    'Glass': 0.85,         # kg CO2 per kg
    'Aluminum': 8.14       # kg CO2 per kg
}

# Calculate emissions
df['CO2_kg'] = df.apply(
    lambda row: row['Weight_kg'] * emission_factors.get(row['Material'], 0),
    axis=1
)

total_co2 = df['CO2_kg'].sum()
print(f"Total Carbon Footprint: {total_co2:,.0f} kg CO2")
print(f"Equivalent: {total_co2/1000:,.1f} tonnes CO2")

Emission Factors Database

Material Emission Factors (Embodied Carbon)

python
# Comprehensive emission factors database (kg CO2e per kg material)
EMISSION_FACTORS_KG = {
    # Concrete and cement
    'Concrete_C20': 0.10,
    'Concrete_C30': 0.13,
    'Concrete_C40': 0.16,
    'Concrete_C50': 0.19,
    'Cement_Portland': 0.83,
    'Mortar': 0.20,

    # Metals
    'Steel_Reinforcing': 1.85,
    'Steel_Structural': 1.55,
    'Steel_Recycled': 0.47,
    'Aluminum_Primary': 8.14,
    'Aluminum_Recycled': 0.52,
    'Copper': 2.71,

    # Masonry
    'Brick_Clay': 0.24,
    'Brick_Concrete': 0.12,
    'Stone_Natural': 0.06,
    'Block_Concrete': 0.10,

    # Wood (negative = carbon sequestration)
    'Timber_Softwood': -1.60,
    'Timber_Hardwood': -1.40,
    'Plywood': 0.45,
    'CLT': -1.20,          # Cross-Laminated Timber
    'Glulam': -1.10,

    # Insulation
    'Insulation_Mineral': 1.20,
    'Insulation_EPS': 3.29,
    'Insulation_XPS': 3.45,
    'Insulation_Cellulose': 0.10,

    # Glass
    'Glass_Float': 0.85,
    'Glass_Double': 1.30,
    'Glass_Triple': 1.80,

    # Plastics
    'PVC': 2.61,
    'HDPE': 1.93,
    'Polycarbonate': 5.00,

    # Other
    'Gypsum_Board': 0.39,
    'Ceramic_Tile': 0.78,
    'Asphalt': 0.05
}

# Emission factors per volume (kg CO2e per m³)
EMISSION_FACTORS_M3 = {
    'Concrete_C30': 312,    # ~2400 kg/m³ * 0.13
    'Steel': 14430,         # ~7800 kg/m³ * 1.85
    'Timber': -800,         # ~500 kg/m³ * -1.6
    'Brick': 432,           # ~1800 kg/m³ * 0.24
    'Glass': 2125           # ~2500 kg/m³ * 0.85
}

Carbon Footprint Calculator

Basic Calculator

python
class CarbonCalculator:
    """Calculate carbon footprint for construction projects"""

    def __init__(self, emission_factors=None):
        self.factors = emission_factors or EMISSION_FACTORS_KG
        self.results = {}

    def calculate_embodied_carbon(self, df, material_col='Material',
                                   weight_col='Weight_kg'):
        """Calculate embodied carbon from materials"""
        df = df.copy()

        # Map materials to emission factors
        df['Emission_Factor'] = df[material_col].map(self.factors).fillna(0)
        df['CO2_kg'] = df[weight_col] * df['Emission_Factor']

        # Summary by material
        summary = df.groupby(material_col).agg({
            weight_col: 'sum',
            'CO2_kg': 'sum'
        }).round(2)

        self.results['embodied'] = {
            'total_kg': df['CO2_kg'].sum(),
            'by_material': summary,
            'details': df
        }

        return df

    def calculate_transport_carbon(self, df, distance_col='Distance_km',
                                    weight_col='Weight_kg',
                                    transport_type='truck'):
        """Calculate transport emissions"""
        # Transport emission factors (kg CO2 per tonne-km)
        transport_factors = {
            'truck': 0.062,
            'rail': 0.022,
            'ship': 0.016,
            'air': 0.602
        }

        factor = transport_factors.get(transport_type, 0.062)

        df = df.copy()
        df['Transport_CO2_kg'] = (df[weight_col] / 1000) * df[distance_col] * factor

        self.results['transport'] = {
            'total_kg': df['Transport_CO2_kg'].sum(),
            'factor_used': factor,
            'transport_type': transport_type
        }

        return df

    def calculate_construction_carbon(self, df,
                                       equipment_hours=None,
                                       fuel_consumption=None):
        """Calculate construction phase emissions"""
        # Equipment emission factors (kg CO2 per hour)
        equipment_factors = {
            'excavator': 25.0,
            'crane': 18.5,
            'concrete_pump': 22.0,
            'loader': 15.0,
            'compactor': 8.0,
            'generator': 12.0
        }

        if equipment_hours:
            construction_co2 = sum(
                hours * equipment_factors.get(equip, 15.0)
                for equip, hours in equipment_hours.items()
            )
        elif fuel_consumption:
            # Diesel: 2.68 kg CO2 per liter
            construction_co2 = fuel_consumption * 2.68
        else:
            construction_co2 = 0

        self.results['construction'] = {
            'total_kg': construction_co2
        }

        return construction_co2

    def get_total_footprint(self):
        """Get total carbon footprint"""
        total = sum(
            r.get('total_kg', 0)
            for r in self.results.values()
        )
        return {
            'total_kg': total,
            'total_tonnes': total / 1000,
            'breakdown': {k: v.get('total_kg', 0) for k, v in self.results.items()}
        }

    def generate_report(self):
        """Generate carbon footprint report"""
        footprint = self.get_total_footprint()

        report = []
        report.append("=" * 50)
        report.append("CARBON FOOTPRINT REPORT")
        report.append("=" * 50)
        report.append("")
        report.append(f"Total Carbon Footprint: {footprint['total_tonnes']:,.2f} tonnes CO2e")
        report.append("")
        report.append("Breakdown:")

        for category, value in footprint['breakdown'].items():
            pct = (value / footprint['total_kg'] * 100) if footprint['total_kg'] > 0 else 0
            report.append(f"  {category.capitalize():15s}: {value:>12,.0f} kg ({pct:>5.1f}%)")

        report.append("")
        report.append("=" * 50)

        return "\n".join(report)

Usage Example

python
# Load project data
elements = pd.read_excel("bim_export.xlsx")

# Initialize calculator
calc = CarbonCalculator()

# Calculate embodied carbon
elements = calc.calculate_embodied_carbon(
    elements,
    material_col='Material',
    weight_col='Weight_kg'
)

# Add transport emissions
elements['Distance_km'] = 50  # Average transport distance
elements = calc.calculate_transport_carbon(
    elements,
    distance_col='Distance_km',
    weight_col='Weight_kg',
    transport_type='truck'
)

# Construction phase
equipment_usage = {
    'excavator': 120,
    'crane': 500,
    'concrete_pump': 80,
    'loader': 200
}
calc.calculate_construction_carbon(equipment_hours=equipment_usage)

# Generate report
print(calc.generate_report())

# Get detailed breakdown
footprint = calc.get_total_footprint()

Life Cycle Assessment (LCA)

Full LCA Calculation

python
class ConstructionLCA:
    """Life Cycle Assessment for construction projects"""

    def __init__(self, building_lifespan=50):
        self.lifespan = building_lifespan
        self.phases = {}

    def calculate_a1_a3(self, materials_df):
        """Product stage: Raw material supply, transport, manufacturing"""
        materials_df['A1_A3'] = materials_df.apply(
            lambda row: row['Weight_kg'] * EMISSION_FACTORS_KG.get(row['Material'], 0),
            axis=1
        )
        self.phases['A1-A3'] = materials_df['A1_A3'].sum()
        return self.phases['A1-A3']

    def calculate_a4(self, materials_df, avg_distance_km=100):
        """Transport to site"""
        # 0.062 kg CO2 per tonne-km for truck
        self.phases['A4'] = (materials_df['Weight_kg'].sum() / 1000) * avg_distance_km * 0.062
        return self.phases['A4']

    def calculate_a5(self, construction_energy_kwh, waste_factor=0.05):
        """Construction/installation process"""
        # Electricity emission factor varies by region (0.4 kg CO2/kWh average)
        energy_emissions = construction_energy_kwh * 0.4
        # Waste emissions (estimate 5% material waste)
        self.phases['A5'] = energy_emissions
        return self.phases['A5']

    def calculate_b1_b7(self, annual_energy_kwh, maintenance_co2_annual=0):
        """Use stage: Operation, maintenance, repair, replacement"""
        annual_operation = annual_energy_kwh * 0.4
        total_operational = (annual_operation + maintenance_co2_annual) * self.lifespan
        self.phases['B1-B7'] = total_operational
        return self.phases['B1-B7']

    def calculate_c1_c4(self, materials_df, demolition_energy_kwh=0):
        """End of life: Deconstruction, transport, processing, disposal"""
        # Demolition energy
        demolition = demolition_energy_kwh * 0.4
        # Transport to disposal (50 km average)
        transport = (materials_df['Weight_kg'].sum() / 1000) * 50 * 0.062
        # Landfill emissions (rough estimate)
        disposal = materials_df['Weight_kg'].sum() * 0.01

        self.phases['C1-C4'] = demolition + transport + disposal
        return self.phases['C1-C4']

    def calculate_d(self, recycled_materials_df):
        """Module D: Benefits beyond system boundary (recycling credits)"""
        # Recycling credits (negative emissions)
        credits = recycled_materials_df.apply(
            lambda row: -row['Weight_kg'] * EMISSION_FACTORS_KG.get(row['Material'], 0) * 0.5,
            axis=1
        ).sum() if len(recycled_materials_df) > 0 else 0

        self.phases['D'] = credits
        return self.phases['D']

    def get_total_lca(self):
        """Calculate total life cycle emissions"""
        embodied = self.phases.get('A1-A3', 0) + self.phases.get('A4', 0) + self.phases.get('A5', 0)
        operational = self.phases.get('B1-B7', 0)
        end_of_life = self.phases.get('C1-C4', 0)
        credits = self.phases.get('D', 0)

        return {
            'embodied_carbon': embodied,
            'operational_carbon': operational,
            'end_of_life_carbon': end_of_life,
            'recycling_credits': credits,
            'total_lifecycle': embodied + operational + end_of_life + credits,
            'phases': self.phases
        }

    def get_carbon_intensity(self, floor_area_m2):
        """Calculate carbon intensity per m²"""
        lca = self.get_total_lca()
        return {
            'embodied_per_m2': lca['embodied_carbon'] / floor_area_m2,
            'operational_per_m2_year': lca['operational_carbon'] / (floor_area_m2 * self.lifespan),
            'total_per_m2': lca['total_lifecycle'] / floor_area_m2
        }

Reporting and Visualization

Carbon Report Generation

python
def generate_carbon_report(df, project_name, floor_area_m2):
    """Generate comprehensive carbon footprint report"""

    # Calculate totals
    total_co2 = df['CO2_kg'].sum()
    co2_per_m2 = total_co2 / floor_area_m2

    # By category
    by_category = df.groupby('Category')['CO2_kg'].sum().sort_values(ascending=False)

    # By material
    by_material = df.groupby('Material')['CO2_kg'].sum().sort_values(ascending=False)

    report = {
        'project': project_name,
        'floor_area_m2': floor_area_m2,
        'total_co2_kg': total_co2,
        'total_co2_tonnes': total_co2 / 1000,
        'co2_per_m2': co2_per_m2,
        'by_category': by_category.to_dict(),
        'by_material': by_material.to_dict(),
        'benchmark_comparison': classify_carbon_intensity(co2_per_m2)
    }

    return report

def classify_carbon_intensity(co2_per_m2):
    """Classify building carbon intensity against benchmarks"""
    # Typical benchmarks for embodied carbon (kg CO2e/m²)
    if co2_per_m2 < 300:
        return {'rating': 'A+', 'description': 'Ultra-low carbon'}
    elif co2_per_m2 < 500:
        return {'rating': 'A', 'description': 'Low carbon'}
    elif co2_per_m2 < 750:
        return {'rating': 'B', 'description': 'Below average'}
    elif co2_per_m2 < 1000:
        return {'rating': 'C', 'description': 'Average'}
    elif co2_per_m2 < 1250:
        return {'rating': 'D', 'description': 'Above average'}
    else:
        return {'rating': 'E', 'description': 'High carbon'}

def export_carbon_report(report, filepath):
    """Export carbon report to Excel"""
    with pd.ExcelWriter(filepath, engine='openpyxl') as writer:
        # Summary sheet
        summary_df = pd.DataFrame({
            'Metric': ['Total CO2 (tonnes)', 'CO2 per m²', 'Rating', 'Floor Area'],
            'Value': [
                f"{report['total_co2_tonnes']:,.1f}",
                f"{report['co2_per_m2']:,.0f} kg/m²",
                report['benchmark_comparison']['rating'],
                f"{report['floor_area_m2']:,.0f} m²"
            ]
        })
        summary_df.to_excel(writer, sheet_name='Summary', index=False)

        # By category
        cat_df = pd.DataFrame.from_dict(report['by_category'], orient='index', columns=['CO2_kg'])
        cat_df.to_excel(writer, sheet_name='By Category')

        # By material
        mat_df = pd.DataFrame.from_dict(report['by_material'], orient='index', columns=['CO2_kg'])
        mat_df.to_excel(writer, sheet_name='By Material')

Carbon Reduction Strategies

Material Optimization

python
def suggest_carbon_reduction(df, material_col='Material'):
    """Suggest material substitutions to reduce carbon"""

    # Low-carbon alternatives
    alternatives = {
        'Concrete_C40': ('Concrete_C30', 0.19, 0.13),  # (alt, current_factor, alt_factor)
        'Steel_Structural': ('Steel_Recycled', 1.55, 0.47),
        'Aluminum_Primary': ('Aluminum_Recycled', 8.14, 0.52),
        'Insulation_EPS': ('Insulation_Cellulose', 3.29, 0.10),
        'Brick_Clay': ('Timber_CLT', 0.24, -1.20)
    }

    suggestions = []

    for material, (alt, current, alt_factor) in alternatives.items():
        subset = df[df[material_col] == material]
        if len(subset) > 0:
            current_co2 = subset['Weight_kg'].sum() * current
            alt_co2 = subset['Weight_kg'].sum() * alt_factor
            saving = current_co2 - alt_co2

            suggestions.append({
                'current_material': material,
                'alternative': alt,
                'current_co2_kg': current_co2,
                'alternative_co2_kg': alt_co2,
                'potential_saving_kg': saving,
                'saving_percent': (saving / current_co2 * 100) if current_co2 > 0 else 0
            })

    return pd.DataFrame(suggestions).sort_values('potential_saving_kg', ascending=False)

Quick Reference

MetricFormula
Embodied CarbonWeight_kg × Emission_Factor
Transport Carbon(Weight_tonnes) × Distance_km × 0.062
Carbon IntensityTotal_CO2 / Floor_Area_m2
LCA TotalA1-A3 + A4 + A5 + B1-B7 + C1-C4 + D

Common Emission Factors

Materialkg CO2e/kgkg CO2e/m³
Concrete C300.13312
Steel (new)1.8514,430
Steel (recycled)0.473,666
Timber-1.60-800
Brick0.24432
Aluminum8.1421,978

Resources

  • Book: "Data-Driven Construction" by Artem Boiko, Chapter 3.3
  • Website: https://datadrivenconstruction.io
  • ICE Database: Inventory of Carbon and Energy
  • EN 15978: Sustainability of construction works standard

Next Steps

  • See cost-prediction for cost-carbon optimization
  • See qto-report for extracting quantities for CO2 calculation
  • See data-visualization for carbon dashboards