Design for structural adaptation: Economic feasibility of an implementation for Swedish timber buildings

As the construction industry is progressively adopting circular economy principles, there is an increased interest in prolonging the service lives of buildings by designing them to be adaptable. This is particularly relevant for timber buildings, as extended-use phases promote prolonged carbon storage and sustainable forestry. Applying the concept of Design for Structural Adaptation (DfSA) to load-bearing timber may grant such benefits, yet it is uncertain whether there are motivations for stakeholders to apply the concept on an industrial scale. In particular, the economic implications of implementing DfSA for timber are currently unclear. This study addresses this uncertainty by investigating the economic feasibility of applying DfSA to a theoretical multi-residential cross-laminated timber building in Sweden. A model for comparative cost–benefit analysis was developed and applied to two alternatives: a business-as-usual building and one designed for structural adaptation. A sensitivity analysis was performed to explore the factors determining the economic feasibility of DfSA, and a best- and worst-case scenario was developed. The results showed that a low investment cost for DfSA is the most crucial factor in determining its economic feasibility.