Upcycling CLT production waste: a computational design and fabrication framework and a proof-of-concept demonstrator

Increasing the use of wood as a construction material and implementing circular economy principles are possible ways of reducing the environmental impact of the building construction sector. However, with an increasing use of timber and mass timber products in buildings, the amount of wood production waste is increasing as well. Wood production waste is typically downcycled and not considered as a resource for construction. This is particularly questionable in the case of Cross-Laminated Timber (CLT). Compared to other types of engineered wood products, its production requires large amounts of raw material and results in large amounts of waste. In contrast to downcycling, upcycling CLT production waste bears the promise of preserving or even increasing the material’s value, which makes it economically more compelling. In this paper, we present a prototypical computational design and digital fabrication workflow that enables the use of CLT production waste in prefabricated assemblies, potentially to be used as wall or façade elements, ideally with modular qualities. We elaborate on how the application of this workflow enabled the design and construction of a full-scale demonstrator, which serves as a proof-of-concept, and share insights gained during and after its construction. Finally, the paper provides an overview of possible applications and discusses the adjustability of the workflows for other design principles and construction systems.