Wood vs Concrete Carbon Calculator

Embodied carbon refers to the greenhouse gas emissions produced during the extraction, manufacturing, transportation, and installation of building materials — before the building is ever occupied. It typically accounts for 11% of global energy-related CO₂ emissions. Choosing lower-carbon materials like wood over concrete can significantly reduce a project's total carbon footprint.

Trees absorb CO₂ from the atmosphere as they grow, locking carbon into their fibers. When timber is harvested and used in construction, that carbon remains stored in the wood for the life of the building — potentially 50 to 100+ years. This biogenic carbon sequestration is what makes wood a carbon-storing material rather than a purely carbon-emitting one.

GWP is a measure of how much heat a greenhouse gas traps in the atmosphere over a given time period, expressed relative to CO₂. In construction, GWP is typically reported in kg CO₂ equivalent per square meter of floor area (kg CO₂e/m²) over a 100-year timeframe. Lower GWP values indicate a lower climate impact.

In most cases, yes — mass timber like CLT and glulam stores significant biogenic carbon and requires far less energy-intensive processing than concrete or steel. However, the comparison depends on factors like concrete mix design (low-carbon mixes with supplementary cementitious materials can close the gap), transportation distances, and the source region's forest management practices.

If no wood volume is provided, the calculator auto-estimates it based on your floor area, number of stories, and selected structural system. These estimates are based on typical structural framing ratios published in wood industry research. For more accurate results, enter the actual volume of structural wood products from your project's structural drawings.

This metric expresses how quickly US and Canadian managed forests regrow the volume of wood used in your project — shown in minutes. It contextualizes the scale of timber use relative to ongoing forest growth, demonstrating that responsibly sourced wood is a truly renewable resource. A result of under 60 minutes means the forest replaces the harvested wood in under an hour of continuous growth.

SCMs such as fly ash, slag, and silica fume replace a portion of Portland cement in a concrete mix. Since cement production is the most carbon-intensive step, substituting 30–50% of cement with SCMs can reduce concrete's GWP by 25–45%. The calculator allows you to model standard versus low-carbon concrete mixes to see how the comparison shifts.

This calculator is focused on structural assemblies — the primary framing system of a building. For flooring-specific comparisons (e.g. solid hardwood vs vinyl vs carpet), dedicated flooring carbon tools are more appropriate. However, the wood product options include solid hardwood, which can give a reasonable indication of flooring-scale carbon benefits.