Paradigm shift for a circular economy in timber construction

The construction industry has a significant impact on the environment. According to the United Nations, it is responsible for about 40 percent of energy-related CO2 emissions and more than half of global resource consumption. In order to reduce these emissions and respect planetary boundaries, sustainable use of (natural) resources, the use of renewable resources and keeping building materials in the material cycle for as long as possible are a must. The implementation of circular economy principles in timber construction is being widely discussed. To date, there is a general lack of understanding of the terms and concepts necessary for the appropriate transfer of the principles of circular economy to modern timber construction. Theoretical explications cover a broad spectrum of viewpoints, however, an overview of relevant topics for the industry is not yet available. First experiences show that technical, constructional and logistical challenges need to be overcome. The circularWOOD research project addresses relevant questions on the transfer of circular principles to modern timber construction. The report provides an overview of the findings in relevant literature, analyses obstacles and potentials from the perspective of the timber construction industry, summarises experiences from initial implementation projects and outlines elements for a future vision of circular economy in timber construction. The focus of the project is on high-quality material reuse. The method includes a comprehensive review of available literature followed by an empirical investigation focusing on a stakeholder analysis, implementation practices in case studies and expert interviews. The findings are iteratively linked, future scenarios derived and recommendations for action formulated. The results serve to classify and synthesise theoretical findings and practical experience on the circularity of timber buildings and describe solution-oriented options by presenting future scenarios. They formulate concrete research needs and recommendations for practical implementation. The results contribute to supporting decision-makers and stakeholders in building and planning practice and to taking the step towards upscaling circularity in modern timber construction.