BIM, CAD and GIS – what’s in a name?

Report from the Association for Geographic Information (AGI) GeoCommunity '11 conference in Nottingham, UK

So you know what GIS (Geographic Information System) and CAD (Computer Aided Design) stand for, what about BIM? It was new to me. Building information modelling is defined as the process of generating and managing building data during its life cycle. The Building Information Models encompass building geometry and quantities and properties of building components. Pieces can carry attributes for selecting and ordering them automatically, providing cost estimates and well as material tracking and ordering (Wikipedia 2011).

 A paper at AGI 11 by Anne Kemp from Atkins Limited, asked the question whether BIM is geospatial? Apparently BIMs are causing huge consternation and debate, partly from confusion raised by the name. BIMs are not just about buildings but cover all infrastructure and it’s not just a model to visualise objects but the process to generate and manage the information for the entire life cycle from planning and design, through to delivery for operation and even decommissioning. The initial process of creating and utilising a BIM necessarily involves all people in the supply chain with the objective to hand over the BIM to the infrastructure owner on completion.

Anne pointed out that the objective of BIMs are to ensure that the right people get the right information at the right time to introduce significant cost savings. By 2016 all UK government funded infrastructure projects must use BIM with the aim to introduce 20% savings across the construction industry.

From my experience supporting a GIS repository for all contractors working on the Maribyrnong Defence Site, I can see the potential for savings. In the Maribyrnong project, all contractors had access to relevant and timely information about the site and that were created by other consultant contractors. This avoided duplication or, worse, this data being ignored.

Anne’s paper was intended to be controversial but raises the question, are BIMs really something just in the domain of CAD (ie architects and engineers) and not GIS. Where does spatial fit in? What is the boundary between CAD and GIS? Why is there a boundary at all? CAD is great for design processes and communicating outcomes, and as someone in the AGI 11 audience said, at enabling intuitive interaction with complex data. However, these objects obviously have a geography.

The way I see it is that the role of spatial, in particular, geographic information, is to make these objects more intelligent. It is the spatial relationships, the topology, between the infrastructure objects and the surrounding environment that optimises the value of these data; like connecting neurons to create intelligence.

Earlier in the week, I visited a colleague working for architects Woods Bagot who showed me a 3D CAD model of inner London. There were hundreds and hundreds of buildings each distinctly represented by the shape of their built form. Wow, that’s a fancy model. Consider, what if each of those buildings and other infrastructure was represented by a comprehensive model of their internal and external features, a BIM? Yes, that would be a hell of lot of data but as Moore’s Law of Computing power and the recent explosion in standard hard disk capacities suggest, it will only be a matter of time before petabyte storage becomes ubiquitous.

It will be the geospatial relationships between all elements, the topology, that transform these models of cities and buildings from things of beauty to intelligent information networks. The AGI community have formed a special interest group to examine the role of the GI community in the design of BIMs. Perhaps the CRC for Spatial Information should be looking at this area too.

For more information about the UK government objectives for BIM see

Rate this item
(0 votes)

Graeme Martin

Graeme is passionate about devising solutions using geospatial information to assist people to make decisions. Graeme is Spatial Vision’s General Manager for Operations and still leads major consulting projects for customers.

For over 25 years Graeme has assisted a range of organisations with strategic advice, design of bespoke information systems, stakeholder engagement and skills transfer.

Graeme has worked across a range of sectors including international development assistance, emergency services, water utilities, natural resource management, commercial services and local government.

For any enquiries please contact us on 1300 36 67 96 or contact Graeme directly via email

Corporate Band

     Mapscape     Check Site     Gis Journey     SV Maps

Login to post comments
Go to top