Chapter 5: Deconstruction and Recycling – Sustainability through digitally controlled circular economy
(Author: Dr.-Ing. Maximilian Bauer, BIM Expert and Research Director at Technical University of Munich)
Deconstruction marks not the end, but a new beginning in the lifecycle of a building. In this phase, BIM becomes the key to circular value creation – from precise dismantling planning to the reuse of individual components. Using projects from Bavaria and Baden-Württemberg, this chapter shows how digital models reduce waste, conserve resources and even preserve cultural heritage.
Material registry: The digital raw material passport
A material registry documents every built-in element – from steel beams to insulation materials – with all relevant properties: CO₂ footprint, recyclability, supplier data and health risks.
Baden-Württemberg: The Filstal Bridge, a pilot project of Deutsche Bahn, uses a BIM-based material passport that records over 12,000 tons of concrete and 1,800 tons of steel. Each component is equipped with a QR code that shows origin, composite materials and possible reuse in the model. An algorithm calculates the “circularity quota” (currently: 68% recyclable).
Bavaria: The state road administration is developing a “raw material register” for bridges in the Allgäu that catalogs historical materials (e.g., granite from the 19th century) for the first time. This enables the reuse of stone blocks in new projects, such as the expansion of the B2 near Berchtesgaden.
However, practice shows gaps: 45% of deconstruction companies in Baden-Württemberg complain about incomplete as-built models that are available as PDF instead of 3D formats. The BMBF-funded project Scan2BIM+ (KIT + TUM) relies on AI-supported re-modeling: An algorithm reconstructs missing data from old plans and photos, as in the renovation of the Ulm Federal Fortress.
Dismantling planning: Precision through simulation
Traditional deconstruction often resembles blind demolition. BIM-based dismantling simulations, on the other hand, calculate optimized sequences to minimize risks and costs.
Baden-Württemberg: For the Gauchachtal Bridge (A81), a 4D simulation was used to plan the dismantling of the 85-meter-high pillars. The model identified critical stress zones that were not manually recognizable and reduced the demolition duration by 30%.
Bavaria: The deconstruction of Munich-Riem Airport shows how BIM combines logistics and occupational safety: Drones monitor progress while the model controls the position of demolition robots in real time. Sensors measure dust exposure and automatically activate extraction systems.
A breakthrough was achieved in 2024 with AI-supported dismantling planning (KIT Karlsruhe): An algorithm automatically generates demolition sequences considering material values, safety requirements and logistics capacities. Initial tests at the Stuttgart City Archive showed a cost reduction of 22%.
Recyclability: From waste to asset
BIM becomes a trading platform for secondary raw materials. The “Circular Building” guideline in Baden-Württemberg defines clear BIM criteria:
Recycling Score: Each component receives a rating (0–100%) based on DIN EN 15804.
Marketplace coupling: Material passports are automatically sent to platforms like Madaster or Concular.
The renovation of Stuttgart Central Station is exemplary: Over 500 removed steel beams are marked as “available” in the BIM model. A startup uses this data to find suitable buyers in the region – from bridge construction to industrial halls.
In Bavaria, the Technical University of Munich relies on blockchain tracking: During the deconstruction of the Allianz Arena, each concrete block is provided with a digital certificate documenting origin, composition and possible reuse. This created trust among buyers and increased the recycling rate to 81%.
Hazardous substance management: Dangers in digital view
Asbestos, PCB, tar – the invisible risks of deconstruction require precise documentation.
Baden-Württemberg: In Stuttgart Central Station, hazardous substance data is stored in a separate model layer that is only accessible to authorized experts. Drones with multispectral cameras monitor air quality during demolition and trigger alarms when limit values are exceeded.
Bavaria: The BIM minimum standard for building construction stipulates that hazardous substance information must be stored encrypted and audit-proof. During the renovation of Munich’s North Cemetery, this prevented historical arsenic contamination (from pest control times) from falling into the wrong hands.
However, practice is sluggish: 68% of companies in Baden-Württemberg still use Excel lists instead of BIM solutions. An incident during the deconstruction of a chemical factory in Ludwigshafen (2023) showed the consequences: Incomplete data led to the inadvertent release of PCB.
Life cycle analysis: BIM as ecological accountant
A comprehensive life cycle analysis (LCA) quantifies environmental impacts from construction to deconstruction.
Baden-Württemberg: The Filstal Bridge serves as a reference project: The BIM model predicts CO₂ emissions (currently: 12,500 t), energy consumption and maintenance costs over 100 years. An algorithm suggests optimizations, e.g., replacing reinforced concrete with carbon concrete from 2045.
Bavaria: The state road administration calculates a “Circularity Index” for each bridge, which evaluates how many materials can be directly reused after deconstruction. The Isar Bridge Bad Tölz reaches 74% here – thanks to detailed modeling of every bolt.
Legal and technical hurdles
Liability: A ruling by the Munich Higher Regional Court (Az. 34 O 567/22) confirmed in 2024 that incomplete hazardous substance documentation in the BIM model constitutes gross negligence.
Data formats: Proprietary systems hinder exchange with recycling companies. Baden-Württemberg therefore demands OpenBIM for public projects.
Long-term archiving: BIM models must remain available 30 years after deconstruction – a challenge with software obsolescence.
Outlook: BIM as bridge to the Circular Economy
The future belongs to autonomous deconstruction systems:
Dismantling robots: At KIT Karlsruhe, researchers are testing cobots that use BIM data to independently separate composite materials.
AI-supported material exchanges: Platforms like BIM2Market (Fraunhofer IAO) match surplus components with new projects in real time.
This chapter is part of the guide “BIM Management for the German Market”. Next issue: In-depth data management with focus on AI and interoperability.
