During her PhD studies, Jiayi Kayee Li presents a robust workflow for regenerative timber construction, establishing that circularity requires innovation at two integrated scales. The thesis first defines the system-level adaptability of volumetric timber modules, validating their structural performance under reconfiguration for urban densification. Crucially, the work then addresses component-level efficiency by developing a methodology to transform timber waste into high-performance structural slabs. Findings confirm that topology optimisation and material recovery can coexist, achieving significant material savings.

This research provides a decisive methodological step, offering architects and engineers an evidence-based methodology for making timber construction truly sustainable and fully circular.

The PhD study was completed at Department of Civil and Architectural Engineering, Faculty of Technical Sciences, Aarhus University.

This summary was prepared by the PhD student.

Time: Friday 20 February 2026 at 13:00
Place: Building 3210, room 03.055, Department of Civil and Architectural Engineering, Aarhus University, Inge Lehmanns Gade 10, 8000 Aarhus C
Title of PhD thesis: Circular Timber Construction by System-level Modularity and Component-level Optimisation
Contact information: Jiayi Kayee Li, e-mail: kayeeli@cae.au.dk, tel.: +45 50523711
Members of the assessment committee:
Associate Professor Dario Parigi, Department of the Built Environment, Aalborg University, Denmark
Associate Professor Ornella Iuorio, The Department of Architecture, Built Environment and Construction Engineering, Politecnico di Milano, Italy
Associate Professor Min Wu (chair), Department of Civil and Architectural Engineering, Aarhus University, Denmark
Main supervisor: Professor Lars Vabbersgaard Andersen, Department of Civil and Architectural Engineering, Aarhus University, Denmark
Co-supervisor: Tenure track Assistant Professor, Markus Matthias Hudert, Department of Civil and Architectural Engineering, Denmark
Language: The PhD dissertation will be defended in English

The defence is public.
The PhD thesis is available for reading at the Graduate School of Technical Sciences/GSTS, Ny Munkegade 120, building 1521, 8000 Aarhus C.