Steffens, Johannes

Diploma Thesis:
2092

Topic:
Material Availability and Scalability – Opportunities and Limitations of circular building materials

Editor:
Johannes Steffens

University Professor Responsible:
Univ.-Prof. Dr.-Ing. Dipl.-Wirt.-Ing. Katharina Kleinschrot

Supervisor:
University Supervisor: Dipl.-Ing. Johanna Gildemeister

Editing Period:
25.03.2026 until 29.07.2026

Abstract: 
This diploma thesis investigates the material availability and scalability of circular
construction materials in the German construction industry from a construction
management perspective. In view of the sector's high resource intensity, the study
employs a systematic literature review and material flow analyses to examine the
potential of the anthropogenic material stock as well as the existing barriers to implementation. The findings reveal that, despite an existing stock of more than 20 billion tonnes, the theoretical substitution rate for primary mineral raw materials is currently limited to approximately 31%. In addition to technical challenges such as material contamination and composite construction methods, the study identifies construction management-related factors as the main barriers, including logistical bottlenecks, temporal mismatches between demolition and new construction, and administrative burdens resulting from the German Substitute Building Materials Ordinance (Ersatzbaustoffverordnung). While recycled construction materials are already economically competitive in civil engineering, the widespread adoption in building construction is hindered by insufficient economies of scale and liability risks. The thesis highlights digitalisation through Building Information Modelling (BIM) and digital material passports as key enablers for improving transparency regarding material quality. Finally, it formulates recommendations for action, emphasizing
a stronger role for public procurement and the internalisation of external costs in order to industrially scale the transformation towards a waste-free construction value chain.