Build complex structures with reclaimed wood

While the construction industry almost exclusively uses 2 in. x 4 in. x 8 ft. pieces of lumber, salvaged lumber from building demolition generally does not have standard dimensions. However, thanks to digital tools that use algorithms, it is possible to effectively reuse these shorter elements in complex structures. This is exactly what the NœudAL installation, which has just been built behind the Faculty of Environmental Design at the Université de Montréal, aims to show.

NodeAL is the result of a research project started in the winter semester 2022 by students of the master’s in architecture and the Laboratory for Architecture, Computer Science and Robotics of the School of Architecture. “In this research workshop, they created algorithmic tools that allow to manage the architectural complexity of a structure that could be built with reclaimed wood of different non-standard lengths”, explains Andrei Nejur, assistant professor at the School of ‘architecture.

Concretely, this means that these tools manage to establish, in a few seconds, what is the best way to use the recovered wood in your project with a minimum of transformations.

“The tools allow you to see how to adapt the structure according to the possibilities of the wood,” says the professor. The power of the algorithms really makes it possible to create very complex structures. And we demonstrated it with NodeAL.”

wood and aluminum

The structure built thus comprises two materials that Quebec produces in large quantities, namely wood and aluminum. AluQuébec, the aluminum cluster, has also financially supported the project.

The wooden uprights were assembled with aluminum knots bent from one millimeter thick sheets stiffened in places with three millimeter thick aluminum plates. “As the sheets used were very thin, the knots are very light: they weigh just over 300 grams,” says Andrei Nejur.

These nodes make it possible to support the structure whose geometry is non-standard with wood that has only been cut with a circular saw to obtain the lengths recommended by the digital tools. Results? Nearly 90% of the 238 wooden planks used in this structure correspond to eight lengths. “Having these measurements made it much easier to cut the wood for construction,” says the professor. And we created very few releases.”

Influencing the industry

To be able to manufacture this structure, the master’s students first had to design the digital tools by performing programming that required the integration of several mathematical and geometric concepts and the development of algorithms.

“We made these digital tools available for free for the industry because we want it to use it to encourage greater use of recovered wood in the construction of new buildings, with a view to the circular economy”, points out Andrei Nejur, who was co-responsible for the workshop with Thomas Balaban, associate practical training professor at the Faculty of Planning. Both are specialists in the influence of digital in the process of creation and design in architecture.

Andrei Nejur would like the construction of a research prototype to become an annual tradition at the UdeM School of Architecture so that construction stakeholders in Quebec can learn about advances in the field.

The construction of NoeudAL in figures