Building visualization
🧮 EN 15978 Compliant · Open-Data · Free for Architects

CO₂ Building Calculator PRO

Compare lifecycle carbon across 8 materials and all EN 15978 phases. With U-value analysis, cost estimation, and professional report generation.

📚 Purpose & Quick Guide

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This tool performs a lifecycle carbon assessment (LCA) for building projects based on EN 15978:2011 — the European standard for environmental performance of buildings. It compares the full carbon footprint of 8 construction materials across all lifecycle phases (A1–D), calculates thermal performance (U-values per EN ISO 6946), and generates professional reports suitable for building permit applications and sustainability documentation. All data is sourced from peer-reviewed research and published Environmental Product Declarations (EPDs).

🎯 Who is this for?
📐
Architects & Engineers
Compare materials early in design. Generate EN 15978-compliant reports for permit applications and sustainability certificates.
🏡
Self-Builders & Developers
Understand the carbon impact of your material choices. See cost estimates and thermal performance side by side.
🎓
Students & Researchers
Explore lifecycle carbon data with sensitivity analysis. All sources and methodology are transparent and verifiable.
🌎
Municipalities & Planners
Evaluate material options for sustainable building policies. Compare biogenic vs. conventional construction at district scale.
🛠️ How to use — 5 steps
1 🏠
Define Project
Choose a preset or enter your building dimensions, wall thickness, and areas.
2 🧱
Select Materials
Click to compare up to 4 materials. Double-click to set a new reference material.
3 📊
View Results
See CO₂ comparison across all EN 15978 phases. Adjust sensitivity parameters.
4 🌡️
Thermal & Cost
Compare U-values against REH limits. Review cost estimates and material properties.
5 📄
Generate Report
Download a professional EN 15978 report as HTML or PDF for your building permit.
🏠
Project
🧱
Materials
📊
Results
🌡️
Thermal & Cost
📄
Report
Step 1 of 5
Project

🏠 Building Project

Building Elements

220 m²
30 cm
80 m²
100 m²
180 m²
90 m²
Always reinforced concrete (EN 15978 A1-A3: ~40 kg CO₂/m²)
Step 1 of 5

🧱 Materials

Click to compare (max 4). Double-click to set as reference. Material data per EN 15978 / ICE Database v3 / published EPDs.

Step 2 of 5
Reference Material — Net Lifecycle CO₂
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kg CO₂-eq (A1-C4)

📊 Net CO₂ Comparison (kg CO₂-eq)

← Absorbed0Emitted →

⚗️ EN 15978 Phase Breakdown

📋 Detailed Breakdown

📈 Sensitivity Analysis

Adjust key assumptions to see how results change.

100 km
100%
30%

🌎 CO₂ Savings Equivalent

Step 3 of 5

🌡️ Thermal Performance & Cost Analysis

💰 Indicative Cost Comparison

* Costs are indicative estimates for Southern Europe 2024-25. Request local quotes for project-specific pricing.

🔧 Material Properties

Step 4 of 5

📄 EN 15978 Assessment Report

Professional report structured per EN 15978. Ready for building permit applications.

Step 5 of 5

📚 Methodology & Standards

🔎 Calculation Formulas (EN 15978)

A1-A3 Product Stage (Cradle to Gate)
Wall_A13 = GWP_A13 × (thickness / 30) × wall_area
IntWall_A13 = GWP_A13 × 0.6 × (thickness / 30) × iw_area
Roof_A13 = GWP_A13 × (0.7 | 0.5bio) × roof_area
Floor_A13 = GWP_A13 × 0.8 × floor_area (0 for biogenic)
Foundation_A13 = 40 kg/m² × fdn_area (reinforced concrete)
A4 Transport
Volume = wall_area × (t/100) + iw_area × (t×0.6/100) + roof×0.15 + floor×0.15
Mass = Volume × density
A4 = Mass × distance × 0.000062 kg CO₂/(t·km)
Source: Ecoinvent v3.8 — Freight lorry 16-32t, EURO 5
A5 Construction
A5 = |Total_A13| × 0.05 (5% construction waste factor)
Source: RICS Whole Life Carbon Assessment (2017), Table 5
Biogenic Carbon Sequestration
Bio = −bio_seq × (wall_area × t/100 + iw_area × t×0.6/100) × bioFactor
Source: Arehart et al. 2020 (J. Cleaner Production); Ip & Miller 2012 (Construction & Building Materials)
Carbonation Credit
Cement/lime: Carb = −|Total_A13| × carbFactor × 0.15
Biogenic:   Carb = −|Wall+IW_A13| × carbFactor × 0.30
Source: Xi et al. 2016 (Nature Geoscience); EN 16757:2017
C1-C4 End of Life
EoL = gwp_eol × (wall_area + iw_area + roof_area) × 0.1
D Benefits Beyond System Boundary
D = d_credit × (wall_area + iw_area) × 0.05
U-Value Calculation
U = 1 / (Rsi + d/λ + Rse)
Rsi = 0.13, Rse = 0.04 (EN ISO 6946)
Source: EN ISO 6946:2017; Portuguese REH reference U ≤ 0.50 W/(m²·K) for Algarve
Net Carbon (Full Lifecycle)
NET = A1-A3 + A4 + A5 + Bio + Carbonation + C1-C4 + D
If NET < 0: carbon-negative building (net carbon sink)

📋 Material Data Sources

Material GWP A1-A3 Bio Seq. λ Source / EPD
🌱 Hempcrete −16 kg/m² 135 kg/m³ 0.065 Arehart et al. 2020; Ip & Miller 2012
🧱 Concrete +65 kg/m² 0 1.4 ICE Database v3.0; Ökobaudat
🪵 Timber +22 kg/m² 25 kg/m³ 0.12 ICE v3.0; IStructE
⚙️ Steel +92 kg/m² 0 50 worldsteel; ICE v3.0
🧊 AAC +35 kg/m² 0 0.11 ICE v3.0; Ökobaudat
🌾 Straw Bale −12 kg/m² 80 kg/m³ 0.06 ScienceDirect; Univ. of Bath
🪵 CLT −5 kg/m² 50 kg/m³ 0.13 NREL 2024; ICE v3.0
Disclaimer: GWP values are indicative averages from peer-reviewed literature and published Environmental Product Declarations (EPDs). Actual values depend on specific products, mix designs, and supply chains. For formal LCA applications, project-specific Environmental Product Declarations should be used. Foundation GWP is fixed at 40 kg CO₂/m² (reinforced concrete, standard practice).

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