Building information modelling : impacts and opportunities for land surveying and the cadastre

Land surveyors are using sophisticated digital equipment and the best available technologies to make observations in the field. These three-dimensional data are rigorously tested and adjusted in the office using advanced mathematical and software tools. In the case of surveying data provided to architects and engineers, a common workflow is for the surveyor to derive representations of surfaces such as terrain in a 2.5D TIN format and to deliver products to clients as 2D vector drawings. From these representations, architects or engineers, reconstruct these simplified 2D drawings into a 3D terrain object. The latest technological advances of building information modelling (BIM) methods create exceptional opportunities for the land surveying profession. The utilisation of BIM not only preserves the spatial integrity of the 3D components of the field observations but also offers numerous additional opportunities. BIM allow the creation of 3D terrain objects which can be used directly by the other stakeholders on the project. Terrain models within a BIM environment can be equipped with attachments and attributes and therefore used to store supplementary information. Custom made additional objects can describe certain features of a property in 3D, such as a building envelope, easements, underground services or even soil layers. Relevant addition data, such as long- or short-term climate data, precipitation and wind conditions, sun-path, and shadow-casting data can be attached or linked. Customised 3D objects can indicate the internal space-structure of a building, and thus support an Indoor Navigation system. Other customised 3D objects may indicate the ownership or strata title, consequently supporting a future 3D Cadastre registration with accurate spatial data. BIM procedures are automatically recorded therefore the BIM models are legally transparent and traceable. The project seeks to investigate the impacts and opportunities presented by Building Information Models for land surveyors, and argues that the 3D modelling and common data environment provided by BIM creates important opportunities for land surveyors and for the surveying industry and profession.