BIMstocks - Digital Urban Mining Platform: Assessing the material composition of building stocks through coupling of BIM to GIS

Status

completed (December 2022)

Motivation and research question

Due to the global increase in energy and resource consumption and the growing amount of waste (Honic et al., 2021), the building stock shows great potential to act as a resource reservoir of raw materials and increase the reuse potential of existing materials and elements. Nevertheless, there are obstacles to this process, as current knowledge of actual building structures is insufficient. The research question is whether the generation of a digital GIS-based urban mining platform (secondary raw materials cadaster) can deliver useful information regarding recycling potential, material flows and waste mass. A Ground-Penetrating Radar and Machine-Learning (ML) Algorithms were be employed to compile an BIM-object-catalogue, as well as Material-Passports in regard of an upscaling of the material masses via a GIS platform on a city level.

Initial situation/status quo

The construction sector is responsible for about 60% of the global raw material extraction ((Almeida, P. et al., 2016)). Therefore, the anthropogenic material stock has been identified as a potential future source of raw materials and has been made the subject of research. Here, two approaches were developed and used to determine the situation. A top-down approach is used to estimate the material composition in the construction sector, which indicates the construction materials in use over time, their composition and adoption. This opens up the possibility of providing data on developments in the overall stock. In contrast, the bottom-up approach functions to carry out detailed studies of buildings in order to determine the building inventory through appropriate extrapolation. At the same time, the building sector is responsible for 60% of the raw materials extracted and causes 40% of the energy-related CO2 emissions. In addition, the rate of new construction is only 3% (Honic & Kovacic, 2020), making the existing stock valuable resources. These facts underline the urgent need for innovative measures regarding the reuse of existing raw material sources and the focus on inventory registers.

Project contents and objectives

The main goal of BIMstocks is to develop a method for a consistent digital documentation of the material composition of the existing building stock for modeling the secondary raw materials cadaster and prediction of the recycling potential, by creating a catalogue of BIM-objects of typically Viennese buildings and follow-up generation of as-built BIM-Models, thus enabling an upscaling to city level. Analyzing and scanning of 10 different use cases, which will represent the variety of typical Viennese buildings, will enable the upscaling to city level. The final aim is to generate a GIS-based Urban Mining Platform, which embeds the obtained information of the use cases and predicts the recycling potential, the material flow and waste mass. Furthermore, a framework will be developed in order to enable the application of urban mining strategies. The framework should describe all individual steps as well as the applied methods.

Thus, the project represents the continuation of the framework developed in the research project SCI_BIM, which investigated an integrated determination of geometry and material by coupling laser scanning and GPR technology for the semi-automated BIM-model generation. SCI_BIM demonstrated that GPR technology needs further testing to a) apply it to different building structures and b) build-up a material database, which would significantly increase the efficiency of material determination.

Methodical procedure and Outlook

Within Vienna, ten buildings were surveyed with the focus on identifying the materials used. On the one hand, invasive methods were applied, i.e. the opening of various building components through drilling or chiseling, and on the other hand, non-invasive methods such as photo documentation, laser scans (mainly for geometric data) and GPR scans. The data was processed in so-called building-components-layer lists. These lists describe the component layers found in terms of layer thickness, material and material densities and served as a basis for BIM modeling, as well as comparison data for GPR data sets, or training data for a ML algorithm, which should automatically assign the GPR data to these component layers in the future. The BIM models created served as the basis for the material mass evaluation, as each component was recorded in these and assigned to building-components-layer lists. The evaluated material masses per use case could also be linked to an existing database from the geographic information system based on information about the building use and the construction period in which the building was built. This enabled an upscaling and thus a forecast of the material masses used in the city of Vienna. Thus, a basis for further research projects was created, which focuses on the coupling of BIM and GIS, as well as the further development of the scanning method GPR and its automated evaluations in connection with a BIM object catalog. At the same time, an evaluation methodology was developed that allows the reuse and recycling potential or conventional disposal paths of materials to be classified, taking into account contaminants, pollutants and hazardous substances in existing buildings.

Project management

Vienna University of Technology, Institute for Interdisciplinary Building Process Management – Integrated Planning and Industrial Building

Project or cooperation partners

• TU Wien, Institut für Wassergüte, Ressourcenmanagement und Abfallwirtschaft Fak. Für Bauingenieurwesen (TU-FAR)
• TU Wien, Institut für Visual Computing & Human-Centered Technology, Fak. für Informatik (TU-VC)
• TU Wien, Institut für Architekturwissenschaften, Digitale Architektur und Raumplanung, Fak. für Architektur und Raumplanung, (TU-DAP)
• Zentralanstalt für Meteorologie und Geodynamik (ZAMG)
• Österreichisches Institut für Bauen und Ökologie GmbH (IBO)
• RM Umweltkonsulenten ZT GmbH (RMU)

Vienna University of Technology,
Institute for Interdisciplinary Building Process Management:
Integrated Planning and Industrial Building
Dipl.-Ing. Dr. techn. Meliha Honic
Karlsplatz 13/E234-2
A-1040 Vienna
Tel.: +43 (1) 58801-21543
E-mail: meliha.honic@tuwien.ac.at
Web: www.industriebau.tuwien.ac.at/forschung/forschungsprojekte/bimstocks/