Embodied carbon is the CO2 emitted during a building material's production and delivery — before any energy is consumed operating the building. Understanding these differences helps architects, builders, and homeowners choose lower-carbon materials without sacrificing structural performance.
Material Carbon Calculator
Embodied Carbon Reference (kg CO₂e per tonne)
| Material | kg CO₂e/tonne | Notes |
|---|---|---|
| Concrete (general) | 250–350 | Cement production is primary source (3% global CO₂) |
| Steel (virgin) | 1,800–2,500 | High energy in blast furnace process |
| Steel (recycled) | 500–900 | Electric arc furnace; highly recyclable |
| Dimensional Lumber | 100–250 | Net carbon varies with forest management |
| CLT / Mass Timber | 80–150 | Often cited as carbon storing (sequesters 1.7t CO₂/t wood) |
| Fired Brick | 280–400 | High-temp kiln firing; very long service life |
| Aluminum (virgin) | 8,000–17,000 | Extremely energy-intensive smelting |
| Straw Bale | 10–50 | Agricultural byproduct; stores carbon long-term |
How to Use the Embodied Carbon Comparison
This embodied carbon comparison tool helps builders, architects, and homeowners understand the upfront climate cost of different building materials. Select a material, enter the quantity in tonnes, and instantly see total CO₂-equivalent emissions compared to alternative options.
Step 1: Select material and quantity
Choose the material you're evaluating. Enter the quantity in metric tonnes — for concrete, a typical residential foundation might use 50-100 tonnes. For structural steel, a single-story commercial building might use 30-80 tonnes.
Step 2: Compare alternatives
The tool shows how your selected material compares to similar alternatives for the same quantity. This is most useful when you have a design choice between structural steel vs CLT framing, or conventional concrete vs insulated concrete forms.
Step 3: Consider the full lifecycle
Embodied carbon is only one part of a building's lifecycle carbon. Durability matters — a high-quality brick wall lasting 200 years has very different lifecycle emissions than an equivalent material requiring replacement every 30 years. Operational energy savings from better insulation can offset higher embodied carbon over a building's lifetime.
FAQ
Is this embodied carbon tool free?
Yes, completely free with no account required.
Is my data safe?
Absolutely. No data is sent to any server.
What is embodied carbon in construction?
Embodied carbon is the total greenhouse gas emissions from a building material's lifecycle: extraction of raw materials, manufacturing, transportation, installation, and end-of-life disposal. It does not include operational energy (heating, cooling) — that's a separate calculation. Embodied carbon can account for 11-15% of global CO2 emissions.
Is wood really carbon negative?
Mass timber and cross-laminated timber (CLT) are often cited as carbon-storing materials because trees sequester carbon during growth. However, the net benefit depends on what happens to the harvested forest, the energy used in manufacturing, and whether the wood is preserved or burned at end-of-life. Sustainably sourced CLT has significantly lower embodied carbon than concrete or steel per structural unit.
How does concrete compare to steel on carbon?
Concrete typically emits 200-400 kg CO2e per tonne — lower than steel per kg, but used in much higher quantities in buildings. Steel emits 1,200-2,500 kg CO2e per tonne of virgin steel, but has high recyclability (95% recycled at end-of-life in the US) which significantly reduces net impact when recycled steel content is high.
What is the lowest carbon structural material?
Mass timber (CLT, glulam) and straw bale construction have the lowest embodied carbon of common structural materials. CLT typically emits 50-150 kg CO2e per tonne, often partially offset by carbon stored in the wood itself. Straw bale is nearly carbon neutral as a material, though it requires careful moisture management.