CO2 Carbon Footprint Tracker

Technical Implementation

import pandas as pd
from datetime import date
from typing import Dict, Any, List
from dataclasses import dataclass, field
from enum import Enum


class EmissionScope(Enum):
    SCOPE_1 = "scope_1"  # Direct emissions
    SCOPE_2 = "scope_2"  # Indirect from energy
    SCOPE_3 = "scope_3"  # Value chain emissions


class MaterialCategory(Enum):
    CONCRETE = "concrete"
    STEEL = "steel"
    ALUMINUM = "aluminum"
    TIMBER = "timber"
    GLASS = "glass"
    INSULATION = "insulation"
    OTHER = "other"


@dataclass
class EmissionFactor:
    material: str
    category: MaterialCategory
    factor: float  # kg CO2e per unit
    unit: str
    source: str


@dataclass
class EmissionEntry:
    entry_id: str
    material: str
    quantity: float
    unit: str
    emission_factor: float
    total_kgco2: float
    scope: EmissionScope
    lifecycle_stage: str  # A1-A3, A4, A5, etc.


class CarbonFootprintTracker:
    def __init__(self, project_name: str, gfa_m2: float):
        self.project_name = project_name
        self.gfa_m2 = gfa_m2
        self.entries: List[EmissionEntry] = []
        self.factors = self._load_default_factors()
        self._counter = 0

    def _load_default_factors(self) -> Dict[str, EmissionFactor]:
        factors = {
            'concrete_m3': EmissionFactor('Concrete C30/37', MaterialCategory.CONCRETE, 250, 'm3', 'EPD Generic'),
            'steel_kg': EmissionFactor('Structural Steel', MaterialCategory.STEEL, 2.5, 'kg', 'EPD Generic'),
            'rebar_kg': EmissionFactor('Reinforcement', MaterialCategory.STEEL, 1.99, 'kg', 'EPD Generic'),
            'aluminum_kg': EmissionFactor('Aluminum', MaterialCategory.ALUMINUM, 8.0, 'kg', 'EPD Generic'),
            'timber_m3': EmissionFactor('CLT Timber', MaterialCategory.TIMBER, -500, 'm3', 'EPD Generic'),
            'glass_m2': EmissionFactor('Double Glazing', MaterialCategory.GLASS, 35, 'm2', 'EPD Generic'),
        }
        return factors

    def add_material(self, material_key: str, quantity: float,
                    lifecycle_stage: str = "A1-A3") -> EmissionEntry:
        if material_key not in self.factors:
            return None

        self._counter += 1
        factor = self.factors[material_key]
        total = quantity * factor.factor

        entry = EmissionEntry(
            entry_id=f"EM-{self._counter:04d}",
            material=factor.material,
            quantity=quantity,
            unit=factor.unit,
            emission_factor=factor.factor,
            total_kgco2=total,
            scope=EmissionScope.SCOPE_3,
            lifecycle_stage=lifecycle_stage
        )
        self.entries.append(entry)
        return entry

    def add_custom_emission(self, description: str, quantity: float, unit: str,
                           factor: float, scope: EmissionScope,
                           stage: str = "A1-A3") -> EmissionEntry:
        self._counter += 1
        entry = EmissionEntry(
            entry_id=f"EM-{self._counter:04d}",
            material=description,
            quantity=quantity,
            unit=unit,
            emission_factor=factor,
            total_kgco2=quantity * factor,
            scope=scope,
            lifecycle_stage=stage
        )
        self.entries.append(entry)
        return entry

    def get_total_emissions(self) -> float:
        return sum(e.total_kgco2 for e in self.entries)

    def get_kgco2_per_m2(self) -> float:
        if self.gfa_m2 == 0:
            return 0
        return self.get_total_emissions() / self.gfa_m2

    def get_by_category(self) -> Dict[str, float]:
        by_category = {}
        for entry in self.entries:
            # Simplified category mapping
            for cat in MaterialCategory:
                if cat.value in entry.material.lower():
                    by_category[cat.value] = by_category.get(cat.value, 0) + entry.total_kgco2
                    break
            else:
                by_category['other'] = by_category.get('other', 0) + entry.total_kgco2
        return by_category

    def get_by_stage(self) -> Dict[str, float]:
        by_stage = {}
        for entry in self.entries:
            stage = entry.lifecycle_stage
            by_stage[stage] = by_stage.get(stage, 0) + entry.total_kgco2
        return by_stage

    def get_summary(self) -> Dict[str, Any]:
        total = self.get_total_emissions()
        return {
            'project': self.project_name,
            'gfa_m2': self.gfa_m2,
            'total_kgco2': round(total, 2),
            'total_tonco2': round(total / 1000, 2),
            'kgco2_per_m2': round(self.get_kgco2_per_m2(), 2),
            'entries_count': len(self.entries),
            'by_stage': self.get_by_stage()
        }

    def export_report(self, output_path: str):
        data = [{
            'ID': e.entry_id,
            'Material': e.material,
            'Quantity': e.quantity,
            'Unit': e.unit,
            'Factor': e.emission_factor,
            'kg CO2e': round(e.total_kgco2, 2),
            'Stage': e.lifecycle_stage
        } for e in self.entries]
        pd.DataFrame(data).to_excel(output_path, index=False)

Quick Start

tracker = CarbonFootprintTracker("Office Tower", gfa_m2=25000)

# Add materials
tracker.add_material('concrete_m3', 5000)
tracker.add_material('steel_kg', 500000)
tracker.add_material('rebar_kg', 150000)
tracker.add_material('timber_m3', 200)

summary = tracker.get_summary()
print(f"Total: {summary['total_tonco2']} ton CO2e")
print(f"Per m2: {summary['kgco2_per_m2']} kg CO2e/m2")

Resources

• DDC Book: Chapter 3.3 - CO2 Estimation