Digitalisation and automation is used more and more in construction, including timber construction. However, often, the material still has to be manually assembled. Now, researchers from ETH Zurich are using a new method for digital timber construction called Spatial Timber Assemblies in a real project for the first time, using load-bearing timber modules that are prefabricated by robots.

In timber construction, computer aided systems can be cut to size by machines, but have to be assembled manually, a process that has many geometric restrictions.

The researchers from ETH Zurich developed a new, digital timber construction method called Spatial Timber Assemblies. This method expands the range of possibilities for traditional timber frame construction by enabling efficient construction and assembly of complex, geometric timber modules.

Using information from a computer-aided design, a robot takes a timber beam and guides it while it is sawed to size. After an automatic tool change, a second robot drills the required holes to connect the beams. Finally, the two robots work together to position the beams in the precise spatial arrangement based on the computer layout.

To prevent unfortunate collisions when positioning the timber beams, the researchers also developed an algorithm that constantly calculates the path of motion for the robot according to the current state of construction.

The construction method is not entirely automatic, however, as workers still have to manually bolt the beams together. Still, the assembly method has the advantage that it can manage without reinforcement plates, as the required rigidity and load-bearing come from the geometric structure. This saves material, and also opens up creative possibilities.

The researchers will prefabricate a total of 6 spatial, geometrically unique wooden structures, which will then be transported to the construction site for the DFAB HOUSE project by National Centre of Competence in Research (NCCR) Digital Fabrication at the Empa and Eawag NEST research and innovation construction site in Dübendorf. This is the first large-scale architectural project that uses construction robots developed by ETH Zurich’s Robotic Fabrication Laboratory.

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