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Wooden buildings produce significantly fewer upfront greenhouse gas emissions (UE-GHG) than those built with concrete, steel, or masonry, according to a new study published in Environmental Research: Infrastructure and Sustainability.

The research, conducted by researcher Ali Amiri and Professor Seppo Junnila at Aalto University, shows that on average, new wooden buildings demonstrated approximately 30% lower UE-GHG emissions than their non-wooden counterparts.

‘Our findings show that wood is not just a renewable material — it’s a powerful tool for climate mitigation in the built environment,’ says lead author Ali Amiri.

The researchers analysed life-cycle assessment (LCA) data from 92 case buildings to calculate the displacement factor (DF), which measures the GHG savings achieved when wood replaces more emission-intensive materials. 

Key findings from the study:

• Low-rise wooden buildings, particularly detached homes, showed the highest displacement factors.
• Process-specific LCA studies yielded higher DF values than input–output LCA studies, underscoring the importance of detailed, project-specific analysis.
• Displacement factors ranged from −0.15 to 0.69, highlighting the need for thoughtful design and technical planning to maximize environmental benefits.

The study also addresses the increasing popularity of hybrid wooden buildings — particularly in mid- and high-rise construction — and calls for a more precise definition of what qualifies as a “wooden” building.

‘Some buildings are being marketed as wooden despite having very limited wood content. To ensure transparent carbon accounting, we need clearer criteria for hybrids,’ says Amiri.

With the construction sector accounting for a significant share of global emissions, the study offers valuable guidance for architects, engineers, and policymakers seeking to reduce climate impacts through material choices.

‘This research provides a concrete reference point for moving toward lower-carbon buildings,’ adds Professor Junnila.

Full article: Amiri, A., & Junnila, S.: in Environmental Research: Infrastructure and Sustainability. DOI: 10.1088/2634-4505/addc16