Learning can be both fun and green! For every person who takes our quiz, we plant one tree. And if you answer correctly, you’ll have the chance to win the big prize: a small forest planted in your name! 🌿✨
The challenge: Evaluate and rank four common building materials based on their CO₂e emissions in life cycle phases A1–A3.
*We collaborate with Tree-Nation — a global platform that since 2006 has made it easy for citizens and companies to plant trees and offset CO₂ emissions. With over 43 million trees planted and a mission to reach 1 trillion trees by 2050, they contribute to reforestation, biodiversity, and transparency in real projects. Learn more at tree-nation.com.
Read more about it here.
Take the quiz now and help plant the future!
Rank the following four common building materials (1 kg, generic environmental data from BR18, 2025) from lowest to highest CO₂e emissions:
From lowest to highest:
- Aerated concrete
- Aluminum
- CLT
- Foam glass
