What is embodied carbon?

Embodied carbon is the total greenhouse gas emissions from extracting, manufacturing, transporting, and installing a construction material (stages A1-A5 in EN 15978). It is measured in kgCO2e (kilogrammes of carbon dioxide equivalent) per kg of material.

Why does timber have a negative carbon factor?

Timber sequesters (stores) carbon during tree growth through photosynthesis. The ICE database assigns -0.72 kgCO2e/kg to softwood, meaning it stores more carbon than is emitted during processing. This benefit only applies while the timber remains in use and is not burned or left to decompose.

Which materials have the highest embodied carbon?

Per kg: aluminium (8.24), PIR insulation (7.56), copper (3.83), structural steel (1.55), glass (1.44). However, per m2 of building, concrete often dominates due to the sheer volume used, despite its relatively low per-kg factor (0.15).

How can I reduce embodied carbon?

Key strategies: use timber instead of steel/concrete where possible, specify recycled content materials, reduce overspecification, minimise waste, source locally (reduce transport), use lower-carbon concrete mixes (GGBS or PFA replacement), and design for deconstruction and reuse.

What is the ICE database?

The Inventory of Carbon and Energy (ICE) database, developed by the University of Bath, is the most widely used source of embodied carbon factors in the UK. It provides kgCO2e/kg values for hundreds of construction materials and is regularly updated.

TradeCalculator

Embodied Carbon Calculator

Calculate the carbon footprint of construction materials

Material

Quantity

How We Calculate This

Select a construction material to look up its carbon factor from the ICE database (kgCO2e per kg). Enter the quantity in kg and the calculator multiplies by the carbon factor. A waste percentage is added (default 10%) to account for site waste. Transport emissions are estimated from the delivery distance. The total embodied carbon is shown with equivalents in tree absorption years and car driving kilometres.

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Verify with your supplier.