Article 1: From timber frame to prefabricated cassettes: the evolution of a building system

After several months of hard work on the plans, we have finally reached a crucial milestone: our architectural project is complete. It is an immense relief after a design phase that turned out to be longer than expected, and a few details will probably still evolve.

But this is more than a simple sign-off on the plans: it marks a major turning point in our approach to building. We are radically changing our construction system. We had originally planned a conventional approach, a timber frame with straw insulation. However, after digging deeper into the feasibility and benefits of straw as a structural material, we are switching to a load-bearing straw system.

What is a load-bearing straw system?

It is actually an innovative hybrid system that combines the best of both worlds. Instead of using straw only as insulation, we use it as a structural, load-bearing element. The concept relies on prefabricated cassettes almost 3 metres long, filled with straw bales. Once filled, these cassettes will be prestressed in the workshop, which gives the straw a remarkable load-bearing capacity.

Each wall element, once prestressed, will be stored until it is needed. The beauty of the system? Once all the elements are made, assembly will be almost like Lego. Each piece fits into the next to form a coherent, solid structure.

Theory and practice

Of course, we know there is always a gap between theory and reality. On paper, it is elegant and simple. But when we start assembling these walls on site, with the weather, the unexpected events of a building site and the coordination of a team, we will find out how this system really behaves.

That is precisely why we chose this approach: it is an exciting technical challenge, and we can’t wait to see how this innovative system performs in real life.