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Political advisers may be pushing building information modelling, but is the industry ready?

The use of virtual 3D Building information modeling (BIM) over the use of aided Computer aided drafting (2D CAD) has been used extensively in various design industries (e.g. aircraft and automotive) for many years but has been slower to be taken up by the construction industry. Paul Morell (The government’s Chief Construction Adviser) has recently given voice to his view that a move to the adoption of BIM is desirable to reduce cost and add value to public sector procurement of buildings.

Architects today routinely use 3d modeling to provide rendered views and walk throughs of design work in progress. It is essential for pitching ideas and communicating with clients. In addition 3d modeling is often used at the production information stage for structural design and analysis, cladding packages or the detailed resolution of specific 3d geometries. However these examples of the use of 3d are often bolt-on additions to the production information, which usually remain a set of 2D abstractions of the building in plan section and elevation. Such 2D information sets use the combination of overlay techniques and human skills in coordinating and interpreting the information though out the construction process

BIM aims to be fundamentally different in that its approach is to utilize a virtual 3d model of the entire project as the whole of a single design and construction information environment from which all 2D and 3D information is generated. This can vary from conventional 2D plans sections elevations and component schedules through to client friendly visualizations and computer aided manufacturing (CAM) models. The concept is that since all the information stems from a single 3D model it is all spatially consistent, coordination errors can be eliminated and the client can have updated 3D visualizations instantly as any changes are made. The completed 3D model is also seen as the ideal vehicle for the repository of as built information for facilities management for the lifecycle of the building.

So much for the theory, how does it stand up in practice? . BIM has been around as a concept a long time. I remember being shown the then in development now defunct GABLE software at Sheffied University over twenty years ago. Leading software houses currently have their own particular flavors - Autodesk’s Revitt, Bentley’s Architecture v8i and Graphisofts ArchiCAD. However BIM is yet to transform the UK construction industry.

"Constructing Excellence, in the built environment" is apparently due to publish a report recommending to government the use of BIM in building procurement. The flavour of UK BIM usage is indicated by five BIM deployment case studies that they published earlier this year. (http://www.constructingexcellence.org.uk//news/article.jsp?id=11042). The five illustrated projects were spread across health, education, commercial and scientific sectors with contract values from £30M to over £300M and all completed within the last 5 years.

The case studies indicate that the key benefits derive from the single source of information leading to better "first fit" spatial integration. This seems to be particularly the case in detailing between different design disciplines. These advantages are credited as leading to reduced requests for information from the construction team, fewer changes by the design team and consequent reductions in programme and budget which have been evaluated as being up to 10% of the overall budget.

However what is also apparent is that the real world usage of BIM doesn’t always match up with the theoretical ideal. Despite the adoption of BIM on projects not all parties adopt its usage and even where they subscribe to the use of BIM internal design development work is often still executed in 2D.

The single most specific virtue of BIM, the use of a single central information source does seem to create its own issues. On the micro level difficulties seem to arise when changes to the single central BIM model made by one party are inadequately flagged up to other team members. Whilst on the broader level parties to the process have concerns about ownership, access and design liability for the single design model. This seems to act as a restraint on its effective transfer from design team, to construction team to the end user client.

The adoption of BIM is undoubtedly a powerful tool in the armory of the Building Designer but is it a panacea for taming the Construction procurement process? Unlikely. It is easy to find examples of how the use of BIM has saved time and money on construction projects but architecture is more than the sum of the resolution of envelope, services and structure clashes. For many BIM remains just one tool amongst many. Encouraging much overdue increase in its usage amongst architects is desirable but is the imposition of it on the design process from the client side really going to be the best way of achieving this?