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Building Information Modelling: the holy grail?

by Sarah Delany
NBS Technical Author

In an article in Construction Computing Magazine published in October 2006, Mervyn Richards (an independent consultant) said that: "For the last three decades the construction industry has been awaiting the 'holy grail', the ability to coordinate the total project process and management through an object modelling environment that has been promised since CAD systems first appeared in the early 1970s."

Over that period we have been offered solutions that have been variably named 3D modelling systems, project modelling, single building models, single model environments, common data environments and now, the latest of them all, the Building Information Model (BIM)."

It would appear that the Building Information Model is going to be the answer to that search but there is a lot of work still to do. However, let's start by trying to clarify exactly what we mean when we use the initials BIM. In Keith Snook's paper, on the RIBA website, he proposes the following definition: “Building Information Modelling is digital representation of physical and functional characteristics of a facility creating a shared knowledge resource for information about it forming a reliable basis for decisions during its life cycle, from earliest conception to demolition.” This is based closely on the US National BIM Standards Committee (NBIMS) definition, which is used in the ASHRAE publication An introduction to Building Information Modelling (BIM). ASHRAE goes on to say "Building Information Modelling is the human activity of using BIM software and other related software, hardware and technologies to create and use in a building information model."

So the acronym is used to represent slightly different things, but what is important to appreciate is that building information modelling is a concept that BIM software products are tools to help support. A building information model should have the capacity to include details of the whole building from all members of the design, build and maintenance team. There are software products available that are marketed as specific to a discipline which completely negates the value of BIM. Products currently available include 'Architectural BIM's, 'Structural BIM's and 'BRIM' for bridge building, and these can lead us to believe that we can have 'MYBIM' and be working efficiently.

Fundamentally a BIM allows 'objects' to be defined in such a way that information about those objects can be developed and added to throughout the construction process and then used as an asset management tool during the occupation phase of a building. At concept design stage the objects are basic and mostly indicate function; as the design is developed specification and costing information can be linked to the objects so that details of materials and performance are in place for the construction phase. Once a building is handed over to the client, the BIM will hold information about maintenance of the objects including dates for replacement and health and safety requirements. At any point when refurbishment or alterations are required the BIM will ensure that detailed records are available, removing the need to carry out surveys.

So it's a powerful tool if used correctly, but how? In many organisations BIM is seen as a type of CAD program and therefore the preserve of the CAD operators. However, it is vital that all members of the design team understand the process and ensure that the software is used to maximum advantage. The project manager needs to be able to use the skills of the CAD team to produce the information in 2D drawing, 3D visualisation and clash detection, specification and costs at any point during the design and construction phase.

Returning to Mervyn Richards' article, he looks at the bigger picture and suggests that BIM will offer better designs, better details, higher quality and increased profits but questions whether this can be achieved without a change in the business processes to allow it to happen or without achieving full interoperability between all BIM products.

He proposes that there will need to be changes in most of the current business processes including:

Collaborative Contracts
Greater definition of the roles and responsibilities of the supply chain
Changes to the professional designers' appointments
New processes for Construction Management
New processes for Contractors' design management
New processes for the Contractors' modelling needs
Full involvement of the manufacturers and fabricators at an early stage
Education and training for the construction team in process and enabling technologies.

He also highlights issues with the traditional social and cultural habits of the staff and project teams and their resistance to change. These issues must be accepted and understood to ensure that the resultant 'blockers' that the culture will mobilise can be dealt with in as sympathetic a way as possible so that the vision may be realised.

There are obvious problems associated with implementing BIM within a design team. Practices do not necessarily use the same software packages so it is difficult to exchange information. At present a great deal of work is being done to achieve interoperability but there are many hurdles to overcome, not least the commercial interests of the vendors. Keeping control of who has responsibility for the information as it passes through the design process and is authorised for construction has to be carefully controlled. Basically, it all comes down to collaboration and the requirement for the whole team to be committed to the process.

A team that takes the decision to collaborate fully at the start of a project will see the BIM software as a fantastic tool in the process and the good news is that there is a tried and tested procedure, well documented, available for all to adopt. BS 1192 gives detailed information to help the CAD operators agree the basic parameters for all aspects of the process including basics such as agreeing the zero point and file numbering. The new CPIC/ BSI publication brings together the procedure described in Production Information: a code of procedure for the construction industry with the lessons learned from the Dti funded Avanti project which tested the procedure on live projects.

It would be foolish to suggest that it is going to be easy to adopt BIM and the collaborative process, but tools and advice are available to help. The savings in time, money and waste are huge and will lead to a more sustainable construction industry – not just in the UK but throughout the world.