Working with Open BIM Standards to Source Legal Spaces for a 3D Cadastre

Abstract

Much work has already been done on how a 3D Cadastre should best be developed. An inclusive information model, the Land Administration Model (LADM ISO 19152) has been developed to provide an international framework for how this can best be done. While this generous framework encompasses a wide range of eventualities, it does not prescribe the data format. One existing source from which data could be obtained is 3D Building Information Models (BIMs), or more specifically in this context, BuildingSMART’s Industry Foundation Class (IFC).

Obtaining data is only one part of the process from moving from a 2D to a 3D Cadastre. A workflow, preferably digital, also needs to be determined to support this. This digital workflow would determine what the 3D Cadastre needs from a 3D IFC BIM and the process of extracting it in addition to exchange requirements. Foundations, however, would need to be laid in order to facilitate this process.

To begin with, the fact that the Industry Foundation Class (IFC) has more than 800 entities means that there is more than one way to satisfy the requirements of cadastral legal spaces. In addition to being large, it leaves options open for adapting the model without entering into the lengthy process of changing it. Working from what is already there would enable data for a 3D Cadastre to be extracted at all stages of the BIM lifecycle, from initial design to the end of the life of the building.

Secondly, experience has shown that process harmonization between organizations is very complex and can lead to conflict. In addition, the processes which need to be harmonised differ from country to country. If possible, therefore, it is something wiser to avoid. This means that while a workflow detailed in BuildingSMART’s Information Delivery Manual (IDM) may be useful within the complex collaborative environment of a BIM project, it is not something which would be standardised within the international Land Administration community. Having said that, communicating the extraction process to the building world in their own lingua franca could be beneficial.