A wooden dome made solely from waste

Missing beam

“Do we have enough beams?” At the back of the carpentry shop, De Wolf is studying the construction plans with doctoral student Matthew Gordon. Their decision to build a geodesic dome was a calculated one. With a basic structure composed of nothing but triangles, it’s one of the most space-​ and energy-​efficient constructions they could have chosen, and it’s also extremely stable. But what’s special about this particular dome is that it uses wooden struts of varying lengths to form the sides of the triangles, thereby making the most efficient use of the reused materials.

Gordon, who has a degree in digital fabrication, programmed an algorithm to calculate the optimum geometry and dimensions based on the available timber. “The aim was to create a programme that would avoid sawing the biggest beams into small pieces and that would use up as much of the wood as possible,” he says. Right now, he’s rechecking that the computer data on the wooden beams corresponds to the reality on the ground.

During their initial preparations, he noticed that some beams were missing. These had already been incorporated in the construction plans – so it was time for chief designer Gordon to put his computer programme’s flexibility to the test. He redid the calculations earlier this morning, and while the rest of the group was busy sawing up the beams, he labelled the new parts with the corresponding numbers from the plans. So far things seem to be back on track – another hurdle overcome.

Platform for reused materials

“That whole episode was a good example of how challenging it can be to work with reused materials,” says De Wolf wryly. The only space left to store the wooden beams had been outside the workshop, so someone had probably disposed of them by mistake. Similar problems abound in the construction industry, she says. Although more and more companies are trading in second-​hand materials, getting hold of these can be costly and time-​consuming, and storage space is often limited. “The ideal thing would be to tell companies about demolition projects well in advance, because then they could start hunting for buyers for the materials right away,” says De Wolf. In reality, however, they often get this information at short notice.

Right now, Byers is using a laser cutter to engrave the last of the QR codes into the wood. Meanwhile, in the construction hall, the rest of the group is starting to build the dome. Working in pairs, the researchers screw the ends of the wooden struts onto the ring-​shaped connections, which are made of sections from an old plastic water sewage pipe, also salvaged from the building in Geneva. Two hours later, the bottom layer of geodesic triangles is already finished. All in all, it takes them just three days to assemble the entire dome – but then they encounter another obstacle.

The wooden struts are putting so much strain on the plastic hubs that they have begun to warp – another illustration of how challenging it is to plan a building when you have almost no information about the reused materials you’re working with. But this is another hurdle that can be overcome thanks to digital fabrication. Using a computer-​numerical-controlled (CNC) milling machine, the researchers cut the salvaged chipboard into discs that fit perfectly into the plastic rings. “As well as improving the dome’s stability, the pieces of chipboard actually make the construction more aesthetically pleasing,” says Raghu, who is leading this part of the project.

Summer course for students

“I’m really proud that my research group managed to build something so beautiful in such a short space of time,” says De Wolf at an informal gathering to mark the building’s completion. In the private sector, very few buildings are currently built according to circular economy principles. “Projects like this one can only succeed if all the stakeholders are on the same page,” says De Wolf.

By bringing together architects, engineers and computer scientists, she hopes to create the right conditions to achieve this – at least within her own research group. Perhaps even more important, she says, is the ability to combine environmental sensitivity with an affinity for the digital world. But that can be a tough call. “On one side you have 
people who are fighting for the environment like Greta Thunberg, and on the other tech geeks like Elon Musk,” says De Wolf. What she’s looking for are digital natives who are willing to dedicate their skills to protecting the environment.

One of De Wolf’s primary goals is to raise awareness of her field of research. Her course 
at this year’s summer school will bring together students from different departments to build another dome from reused materials. This dome will 
remain on the Hönggerberg campus over the summer to showcase her work. She is also planning an exhibition on the circular economy in construction as well as a number of smaller events.

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