Buildings as carbon sinks: The Global Construction C-Sink in Practice

What if our buildings didn’t just emit CO₂ — but stored it long-term?

The Global Construction C-Sink Standard makes this possible by verifying buildings that store biogenic carbon long-term through materials like hemp, wood, cork, straw, cellulose and biochar. Carbon that was once in the atmosphere becomes part of the building itself — traceable, verifiable, and long-lasting. 

In our latest video, Christoph Neururer and Andy Keel from OPENLY presents a real pilot project that shows what climate-friendly construction can look like today: 

• Avoidance first — reducing CO₂-intensive components wherever possible 
• High C-sink potential — hempcrete walls, cork & cellulose insulation, wood structures 
• Innovation — reinforced concrete with biochar to bind additional carbon 
• Designed for disassembly — a house seen as a future raw-material depot 
• Healthy living — controlled ventilation without pipes 

In the house of the pilot project about 350 m³ of hempcrete was used — hemp absorbs ~1.7 kg CO₂ per kg during just three months of growth. Stored safely in the building for decades. 

With the first Global Construction C-Sink verification, OPENLY now:

• Shares knowledge through monthly trainings 
• Acts as Global Construction C-Sink Manager, verifying biogenic carbon sinks in buildings worldwide 

This is how construction becomes part of the climate solution — from day one. 

Watch the video and imagine what our buildings could become.