CircWood: Increasing the Climate Change Mitigation Potential of Wood Used in Construction

The overall aim of the CircWood project was model the effect that recirculating wood within the built environment has on carbon storage in wooden buildings, taking into account different wood use scenarios and the implementation of design-for-disassembly (DfD). In the first part of the project, buildings containing the greatest proportion of wood were identified. It was found that wooden buildings account for about 84% and 99% of the permanent and free-time residential buildings respectively and for 58% of non-residential buildings. Demolition and waste management practices were surveyed with the intention of gaining knowledge about the quantity, quality and dimensions of demolition wood as well as a qualitative assessment of attitudes towards wood cascading. Cascading options were investigated through desk research and interviews. In the final phase of the project, a model was created to demonstrate how retaining wood in the technosphere (through cascading) increases the amount of carbon stored. Augmented levels of cascading (i.e. through DfD) increase the level of carbon stored and for a longer period.

This basic research study has demonstrated that cascading wood from buildings can provide a means of increasing C stored in the built environment, helping to mitigate climate change. Further work is ongoing to assess the substitution effects that accrue from the use of cascaded wood. Design-for-disassembly is seen as a means of increasing the quality and quantity of wood recovered from the demolition of buildings. Modeling suggests that retaining recycled wood in products that last a long time (e.g. as other structural components in buildings), increases the amount of C stored. Nevertheless, the most effective way of increasing C storage is to extend the lifetime of wooden buildings.