What embodied carbon means
Embodied carbon is the CO₂ released while making a material, from quarrying through to the factory gate. For a typical house it is mostly cement and steel, followed by fired clay bricks.
Default factors
- Cement: about 35 kg CO₂ per 50 kg bag
- Ready-mix concrete: about 300 kg CO₂ per m³
- Red clay brick: about 0.6 kg CO₂ each
- Iron and steel: about 2.5 kg CO₂ per kg
- Ceramic tiles: about 12 kg CO₂ per m²
These are typical values. Blended cements (PPC, PSC) and fly-ash bricks have lower emissions, so change the factors if you use them.
Frequently asked questions
How can I lower the carbon of my house?
Use PPC or slag cement, fly-ash or AAC blocks instead of red bricks, and avoid over-designing concrete and steel quantities.
Why is concrete counted separately?
If you buy ready-mix concrete, enter it in m³. If you mix on site, enter the cement, sand and aggregate instead. Do not enter both.
How much CO₂ is in a 1,000 sq ft house?
With the default thumb rules, about 30 tonnes for the main materials, mostly from cement and steel. Use the construction material calculator to get your quantities first.
Sources
- ICE embodied carbon database (Circular Ecology) ↗ – carbon per kg of each material