Development and Integration of LADM and BIM for 3D Cadastre in Iran

The rapid urbanization and development of vertical construction and subsurface spaces in Iran, along with national policy emphasis on transparency in land administration, have highlighted the need to transition from a two-dimensional (2D) to a three-dimensional (3D) cadastre. Iran’s current cadastral system, based on 2D parcel maps, fails to adequately capture complex ownership relationships in multi-story buildings and underground spaces. This study proposes an integrated model combining the Land Administration Domain Model (LADM) country profile with the Industry Foundation Classes (IFC) standard for 3D cadastre implementation. The LADM country profile of Iran was extended to support 3D spatial units. A 3D building model was developed in Autodesk Revit by integrating as-built cadastral maps with architectural drawings and exported in IFC format. Legal attributes were added to Building Information Modeling (BIM) elements in Simplebim via custom Property Sets, allowing physical and legal information to be stored in one IFC file. Functional and interoperability testing in IFC-compatible software showed that the file could be read and used for legal-spatial queries, although the results may depend on each software’s IFC support. For national use, database-level implementation may provide a more reliable option. These results demonstrate that integrating LADM and BIM for a 3D cadastre is technically feasible in Iran at the building scale, as shown by the successful mapping between LADM classes and IFC entities, implementation of custom Property Sets, and interoperability testing across IFC-compatible software platforms.