\r \r

Lifecycle Carbon Calculator for Construction\r

\r

Overview\r

\r Calculate embodied carbon (EC) and lifecycle carbon emissions for construction materials, assemblies, and projects. Support sustainable design decisions and carbon reduction targets.\r \r

Business Case\r

\r Carbon calculation supports:\r

• Regulatory Compliance: Meet carbon reporting requirements\r
• Green Certifications: LEED, BREEAM, Living Building Challenge\r
• Design Optimization: Choose lower-carbon alternatives\r
• Sustainability Goals: Track progress toward net-zero\r \r

Technical Implementation\r

\r

from dataclasses import dataclass, field\r
from typing import List, Dict, Any, Optional\r
from enum import Enum\r
import pandas as pd\r
\r
class LifecycleStage(Enum):\r
    A1_A3 = "Product Stage (A1-A3)"  # Raw materials, transport, manufacturing\r
    A4 = "Transport to Site (A4)"\r
    A5 = "Construction (A5)"\r
    B1_B7 = "Use Stage (B1-B7)"  # Maintenance, repair, replacement\r
    C1_C4 = "End of Life (C1-C4)"  # Demolition, transport, disposal\r
    D = "Beyond Lifecycle (D)"  # Reuse, recycling potential\r
\r
@dataclass\r
class MaterialCarbon:\r
    material_id: str\r
    name: str\r
    category: str\r
    unit: str\r
    carbon_a1_a3: float  # kgCO2e per unit\r
    carbon_a4: float\r
    carbon_a5: float\r
    carbon_b: float\r
    carbon_c: float\r
    carbon_d: float  # Usually negative (credit)\r
    density: float  # kg/m³ if applicable\r
    source: str\r
    epd_url: str = ""\r
\r
@dataclass\r
class AssemblyCarbon:\r
    assembly_id: str\r
    name: str\r
    materials: List[Dict[str, Any]]\r
    total_carbon: float\r
    carbon_by_stage: Dict[str, float]\r
\r
@dataclass\r
class ProjectCarbon:\r
    project_id: str\r
    name: str\r
    gross_area: float\r
    assemblies: List[AssemblyCarbon]\r
    total_embodied_carbon: float\r
    carbon_per_area: float\r
    carbon_by_stage: Dict[str, float]\r
    carbon_by_category: Dict[str, float]\r
    benchmark_comparison: Dict[str, Any]\r
\r
class LifecycleCarbonCalculator:\r
    """Calculate lifecycle carbon for construction."""\r
\r
    # Sample material carbon data (kgCO2e per unit)\r
    DEFAULT_MATERIALS = {\r
        'concrete_30mpa': MaterialCarbon(\r
            material_id='C30', name='Concrete 30MPa', category='Concrete',\r
            unit='m³', carbon_a1_a3=300, carbon_a4=5, carbon_a5=2,\r
            carbon_b=0, carbon_c=10, carbon_d=-20, density=2400,\r
            source='EPD Database'\r
        ),\r
        'concrete_40mpa': MaterialCarbon(\r
            material_id='C40', name='Concrete 40MPa', category='Concrete',\r
            unit='m³', carbon_a1_a3=350, carbon_a4=5, carbon_a5=2,\r
            carbon_b=0, carbon_c=10, carbon_d=-20, density=2400,\r
            source='EPD Database'\r
        ),\r
        'steel_rebar': MaterialCarbon(\r
            material_id='REBAR', name='Steel Reinforcing Bar', category='Steel',\r
            unit='kg', carbon_a1_a3=1.99, carbon_a4=0.05, carbon_a5=0.02,\r
            carbon_b=0, carbon_c=0.05, carbon_d=-0.5, density=7850,\r
            source='WorldSteel EPD'\r
        ),\r
        'steel_structural': MaterialCarbon(\r
            material_id='STEEL', name='Structural Steel', category='Steel',\r
            unit='kg', carbon_a1_a3=1.55, carbon_a4=0.05, carbon_a5=0.03,\r
            carbon_b=0, carbon_c=0.05, carbon_d=-0.8, density=7850,\r
            source='AISC EPD'\r
        ),\r
        'timber_clt': MaterialCarbon(\r
            material_id='CLT', name='Cross-Laminated Timber', category='Timber',\r
            unit='m³', carbon_a1_a3=-500, carbon_a4=10, carbon_a5=5,\r
            carbon_b=0, carbon_c=50, carbon_d=-100, density=500,\r
            source='AWC EPD'\r
        ),\r
        'gypsum_board': MaterialCarbon(\r
            material_id='GYP', name='Gypsum Board 12.5mm', category='Finishes',\r
            unit='m²', carbon_a1_a3=3.2, carbon_a4=0.2, carbon_a5=0.1,\r
            carbon_b=0, carbon_c=0.3, carbon_d=-0.1, density=10,\r
            source='EUROGYPSUM EPD'\r
        ),\r
        'insulation_mineral': MaterialCarbon(\r
            material_id='INS_MW', name='Mineral Wool Insulation', category='Insulation',\r
            unit='m³', carbon_a1_a3=45, carbon_a4=2, carbon_a5=1,\r
            carbon_b=0, carbon_c=5, carbon_d=-2, density=40,\r
            source='EURIMA EPD'\r
        ),\r
        'glass_double': MaterialCarbon(\r
            material_id='GLASS', name='Double Glazed Unit', category='Glazing',\r
            unit='m²', carbon_a1_a3=35, carbon_a4=1, carbon_a5=0.5,\r
            carbon_b=0, carbon_c=2, carbon_d=-5, density=25,\r
            source='Glass for Europe EPD'\r
        ),\r
        'aluminum': MaterialCarbon(\r
            material_id='ALU', name='Aluminum Profile', category='Metals',\r
            unit='kg', carbon_a1_a3=8.0, carbon_a4=0.1, carbon_a5=0.05,\r
            carbon_b=0, carbon_c=0.1, carbon_d=-4.0, density=2700,\r
            source='EAA EPD'\r
        ),\r
    }\r
\r
    # Building type benchmarks (kgCO2e/m²)\r
    BENCHMARKS = {\r
        'Office': {'typical': 500, 'good': 350, 'best': 200},\r
        'Residential': {'typical': 400, 'good': 280, 'best': 150},\r
        'Retail': {'typical': 450, 'good': 320, 'best': 180},\r
        'Industrial': {'typical': 350, 'good': 250, 'best': 150},\r
        'Healthcare': {'typical': 700, 'good': 500, 'best': 350},\r
    }\r
\r
    def __init__(self):\r
        self.materials: Dict[str, MaterialCarbon] = dict(self.DEFAULT_MATERIALS)\r
        self.assemblies: Dict[str, AssemblyCarbon] = {}\r
\r
    def add_material(self, material: MaterialCarbon):\r
        """Add or update a material."""\r
        self.materials[material.material_id] = material\r
\r
    def calculate_material_carbon(self, material_id: str, quantity: float,\r
                                   stages: List[LifecycleStage] = None) -> Dict:\r
        """Calculate carbon for a material quantity."""\r
        if material_id not in self.materials:\r
            raise ValueError(f"Unknown material: {material_id}")\r
\r
        material = self.materials[material_id]\r
\r
        if stages is None:\r
            stages = list(LifecycleStage)\r
\r
        carbon_by_stage = {}\r
        total = 0\r
\r
        for stage in stages:\r
            if stage == LifecycleStage.A1_A3:\r
                carbon = material.carbon_a1_a3 * quantity\r
            elif stage == LifecycleStage.A4:\r
                carbon = material.carbon_a4 * quantity\r
            elif stage == LifecycleStage.A5:\r
                carbon = material.carbon_a5 * quantity\r
            elif stage == LifecycleStage.B1_B7:\r
                carbon = material.carbon_b * quantity\r
            elif stage == LifecycleStage.C1_C4:\r
                carbon = material.carbon_c * quantity\r
            elif stage == LifecycleStage.D:\r
                carbon = material.carbon_d * quantity\r
            else:\r
                carbon = 0\r
\r
            carbon_by_stage[stage.value] = carbon\r
            total += carbon\r
\r
        return {\r
            'material_id': material_id,\r
            'material_name': material.name,\r
            'quantity': quantity,\r
            'unit': material.unit,\r
            'total_carbon': total,\r
            'carbon_by_stage': carbon_by_stage\r
        }\r
\r
    def create_assembly(self, assembly_id: str, name: str,\r
                        components: List[Dict]) -> AssemblyCarbon:\r
        """Create an assembly from multiple materials."""\r
        total_carbon = 0\r
        carbon_by_stage = {stage.value: 0 for stage in LifecycleStage}\r
        material_details = []\r
\r
        for comp in components:\r
            material_id = comp['material_id']\r
            quantity = comp['quantity']\r
\r
            result = self.calculate_material_carbon(material_id, quantity)\r
            total_carbon += result['total_carbon']\r
\r
            for stage, carbon in result['carbon_by_stage'].items():\r
                carbon_by_stage[stage] += carbon\r
\r
            material_details.append({\r
                'material': result['material_name'],\r
                'quantity': quantity,\r
                'unit': result['unit'],\r
                'carbon': result['total_carbon']\r
            })\r
\r
        assembly = AssemblyCarbon(\r
            assembly_id=assembly_id,\r
            name=name,\r
            materials=material_details,\r
            total_carbon=total_carbon,\r
            carbon_by_stage=carbon_by_stage\r
        )\r
\r
        self.assemblies[assembly_id] = assembly\r
        return assembly\r
\r
    def calculate_project_carbon(self, project_id: str, project_name: str,\r
                                  gross_area: float, building_type: str,\r
                                  quantities: List[Dict]) -> ProjectCarbon:\r
        """Calculate total project carbon."""\r
        assemblies = []\r
        total_carbon = 0\r
        carbon_by_stage = {stage.value: 0 for stage in LifecycleStage}\r
        carbon_by_category = {}\r
\r
        for qty in quantities:\r
            if 'assembly_id' in qty:\r
                # Use predefined assembly\r
                if qty['assembly_id'] in self.assemblies:\r
                    assembly = self.assemblies[qty['assembly_id']]\r
                    multiplier = qty.get('multiplier', 1)\r
                    scaled_carbon = assembly.total_carbon * multiplier\r
\r
                    assemblies.append(AssemblyCarbon(\r
                        assembly_id=assembly.assembly_id,\r
                        name=assembly.name,\r
                        materials=assembly.materials,\r
                        total_carbon=scaled_carbon,\r
                        carbon_by_stage={k: v * multiplier for k, v in assembly.carbon_by_stage.items()}\r
                    ))\r
                    total_carbon += scaled_carbon\r
\r
            elif 'material_id' in qty:\r
                # Direct material\r
                result = self.calculate_material_carbon(\r
                    qty['material_id'], qty['quantity']\r
                )\r
                total_carbon += result['total_carbon']\r
\r
                for stage, carbon in result['carbon_by_stage'].items():\r
                    carbon_by_stage[stage] += carbon\r
\r
                # Track by category\r
                material = self.materials[qty['material_id']]\r
                cat = material.category\r
                carbon_by_category[cat] = carbon_by_category.get(cat, 0) + result['total_carbon']\r
\r
        # Calculate metrics\r
        carbon_per_area = total_carbon / gross_area if gross_area > 0 else 0\r
\r
        # Compare to benchmarks\r
        benchmark = self.BENCHMARKS.get(building_type, self.BENCHMARKS['Office'])\r
        benchmark_comparison = {\r
            'carbon_per_area': carbon_per_area,\r
            'typical_benchmark': benchmark['typical'],\r
            'good_benchmark': benchmark['good'],\r
            'best_benchmark': benchmark['best'],\r
            'vs_typical': (carbon_per_area / benchmark['typical'] - 1) * 100,\r
            'rating': self._get_rating(carbon_per_area, benchmark)\r
        }\r
\r
        return ProjectCarbon(\r
            project_id=project_id,\r
            name=project_name,\r
            gross_area=gross_area,\r
            assemblies=assemblies,\r
            total_embodied_carbon=total_carbon,\r
            carbon_per_area=carbon_per_area,\r
            carbon_by_stage=carbon_by_stage,\r
            carbon_by_category=carbon_by_category,\r
            benchmark_comparison=benchmark_comparison\r
        )\r
\r
    def _get_rating(self, carbon: float, benchmark: Dict) -> str:\r
        """Get rating based on benchmark comparison."""\r
        if carbon \x3C= benchmark['best']:\r
            return 'A (Best Practice)'\r
        elif carbon \x3C= benchmark['good']:\r
            return 'B (Good Practice)'\r
        elif carbon \x3C= benchmark['typical']:\r
            return 'C (Typical)'\r
        else:\r
            return 'D (Above Typical)'\r
\r
    def compare_alternatives(self, base_project: ProjectCarbon,\r
                              alternatives: List[Dict]) -> pd.DataFrame:\r
        """Compare carbon of design alternatives."""\r
        comparisons = [{\r
            'Option': 'Base Design',\r
            'Total Carbon (tCO2e)': base_project.total_embodied_carbon / 1000,\r
            'Carbon/m² (kgCO2e)': base_project.carbon_per_area,\r
            'vs Base': '0%',\r
            'Rating': base_project.benchmark_comparison['rating']\r
        }]\r
\r
        for alt in alternatives:\r
            project = self.calculate_project_carbon(\r
                alt['id'], alt['name'], alt['gross_area'],\r
                alt.get('building_type', 'Office'), alt['quantities']\r
            )\r
\r
            change = (project.total_embodied_carbon - base_project.total_embodied_carbon) / base_project.total_embodied_carbon * 100\r
\r
            comparisons.append({\r
                'Option': alt['name'],\r
                'Total Carbon (tCO2e)': project.total_embodied_carbon / 1000,\r
                'Carbon/m² (kgCO2e)': project.carbon_per_area,\r
                'vs Base': f'{change:+.1f}%',\r
                'Rating': project.benchmark_comparison['rating']\r
            })\r
\r
        return pd.DataFrame(comparisons)\r
\r
    def suggest_reductions(self, project: ProjectCarbon) -> List[Dict]:\r
        """Suggest carbon reduction opportunities."""\r
        suggestions = []\r
\r
        # Analyze by category\r
        if 'Concrete' in project.carbon_by_category:\r
            concrete_carbon = project.carbon_by_category['Concrete']\r
            if concrete_carbon > project.total_embodied_carbon * 0.3:\r
                suggestions.append({\r
                    'category': 'Concrete',\r
                    'current_carbon': concrete_carbon,\r
                    'suggestion': 'Consider low-carbon concrete (GGBS/PFA replacement)',\r
                    'potential_reduction': '20-40%',\r
                    'impact': concrete_carbon * 0.3\r
                })\r
\r
        if 'Steel' in project.carbon_by_category:\r
            steel_carbon = project.carbon_by_category['Steel']\r
            if steel_carbon > project.total_embodied_carbon * 0.2:\r
                suggestions.append({\r
                    'category': 'Steel',\r
                    'current_carbon': steel_carbon,\r
                    'suggestion': 'Specify high recycled content steel',\r
                    'potential_reduction': '10-25%',\r
                    'impact': steel_carbon * 0.2\r
                })\r
\r
        # Benchmark-based suggestions\r
        if project.benchmark_comparison['vs_typical'] > 0:\r
            suggestions.append({\r
                'category': 'Overall',\r
                'current_carbon': project.total_embodied_carbon,\r
                'suggestion': 'Project exceeds typical benchmark - review high-carbon elements',\r
                'potential_reduction': f"{abs(project.benchmark_comparison['vs_typical']):.0f}%",\r
                'impact': project.total_embodied_carbon * abs(project.benchmark_comparison['vs_typical']) / 100\r
            })\r
\r
        return sorted(suggestions, key=lambda x: -x['impact'])\r
\r
    def generate_report(self, project: ProjectCarbon) -> str:\r
        """Generate carbon assessment report."""\r
        lines = ["# Embodied Carbon Assessment Report", ""]\r
        lines.append(f"**Project:** {project.name}")\r
        lines.append(f"**Gross Area:** {project.gross_area:,.0f} m²")\r
        lines.append(f"**Assessment Date:** {pd.Timestamp.now().strftime('%Y-%m-%d')}")\r
        lines.append("")\r
\r
        # Summary\r
        lines.append("## Carbon Summary")\r
        lines.append(f"- **Total Embodied Carbon:** {project.total_embodied_carbon/1000:,.0f} tCO2e")\r
        lines.append(f"- **Carbon Intensity:** {project.carbon_per_area:,.0f} kgCO2e/m²")\r
        lines.append(f"- **Rating:** {project.benchmark_comparison['rating']}")\r
        lines.append("")\r
\r
        # By lifecycle stage\r
        lines.append("## Carbon by Lifecycle Stage")\r
        for stage, carbon in project.carbon_by_stage.items():\r
            if carbon != 0:\r
                pct = carbon / project.total_embodied_carbon * 100\r
                lines.append(f"- {stage}: {carbon/1000:,.1f} tCO2e ({pct:.1f}%)")\r
        lines.append("")\r
\r
        # By category\r
        lines.append("## Carbon by Material Category")\r
        for cat, carbon in sorted(project.carbon_by_category.items(), key=lambda x: -x[1]):\r
            pct = carbon / project.total_embodied_carbon * 100\r
            lines.append(f"- {cat}: {carbon/1000:,.1f} tCO2e ({pct:.1f}%)")\r
        lines.append("")\r
\r
        # Benchmark\r
        lines.append("## Benchmark Comparison")\r
        bc = project.benchmark_comparison\r
        lines.append(f"- Project: {bc['carbon_per_area']:.0f} kgCO2e/m²")\r
        lines.append(f"- Typical: {bc['typical_benchmark']} kgCO2e/m²")\r
        lines.append(f"- Good Practice: {bc['good_benchmark']} kgCO2e/m²")\r
        lines.append(f"- Best Practice: {bc['best_benchmark']} kgCO2e/m²")\r
        lines.append("")\r
\r
        # Reduction opportunities\r
        suggestions = self.suggest_reductions(project)\r
        if suggestions:\r
            lines.append("## Reduction Opportunities")\r
            for sug in suggestions[:5]:\r
                lines.append(f"\
### {sug['category']}")\r
                lines.append(f"- **Suggestion:** {sug['suggestion']}")\r
                lines.append(f"- **Potential Reduction:** {sug['potential_reduction']}")\r
                lines.append(f"- **Impact:** {sug['impact']/1000:,.1f} tCO2e")\r
\r
        return "\
".join(lines)\r
```\r
\r
## Quick Start\r
\r
```python\r
# Initialize calculator\r
calc = LifecycleCarbonCalculator()\r
\r
# Calculate project carbon\r
project = calc.calculate_project_carbon(\r
    project_id="PROJ-001",\r
    project_name="Office Building",\r
    gross_area=5000,\r
    building_type="Office",\r
    quantities=[\r
        {'material_id': 'concrete_40mpa', 'quantity': 1500},  # m³\r
        {'material_id': 'steel_rebar', 'quantity': 150000},   # kg\r
        {'material_id': 'steel_structural', 'quantity': 200000},\r
        {'material_id': 'gypsum_board', 'quantity': 8000},    # m²\r
        {'material_id': 'glass_double', 'quantity': 1200},    # m²\r
    ]\r
)\r
\r
print(f"Total Carbon: {project.total_embodied_carbon/1000:,.0f} tCO2e")\r
print(f"Carbon Intensity: {project.carbon_per_area:,.0f} kgCO2e/m²")\r
print(f"Rating: {project.benchmark_comparison['rating']}")\r
\r
# Get reduction suggestions\r
suggestions = calc.suggest_reductions(project)\r
for sug in suggestions:\r
    print(f"- {sug['category']}: {sug['suggestion']}")\r
\r
# Generate full report\r
report = calc.generate_report(project)\r
print(report)\r
```\r
\r
## Dependencies\r
\r
```bash\r
pip install pandas\r
```\r