Building Information Modeling
A less than adequate wikipedia entry on Building Information Modeling can be found here
Building Information Modeling, or 'BIM' is basically a 3D digital building model which has all the information required for the construction of a building. It is the natural progression from model-based design. By integrating information into the model, traditionally kept on separate pieces of paper, it is meant to avoid confusion, save time and make team-working easier.
The main BIM software available are Graphisoft's ArchiCAD, Autodesk's Revit and Bentley Architecture. I'm sure Nemetshek's Vectorworks Architect would love to be included in the list, but because of the 2D way in which you tend build models through plan, I don't feel that it deserves the title of BIM, although it's great software in other senses.
Put simply, because it saves a lot of time. If you simply build your model in 3D, making sure that your building elements have the corect dimensions and material type, your sections, plans, schedules are automatically generated, and updated.The best way to understand is by seeing how it works.
Here are a few helpful features of current software to help you understand what BIM can do:
It is important to note that not all of BIM functionalities are completely defined yet, indeed, it may never stay fixed as architectural practice evolves. Also, it is still only an idea, though developers of ArchiCAD and Autodesk Revit will refute this claim. We might be able to say that we truly have BIM when it becomes the standard method of architectural practice.
I say this because we are far behind the level of integration that has been envisioned. I mean integration between the various professions involved in construction, and consequently of different software. There are fierce proprietary battles between the software developers, who are unwilling to collaborate to use an open standard as a basis for all BIM software. Open standards exist, such as IFC and 'gbXML', but its adoption by ArchiCAD and Revit have been lukewarm.
Having said this, for architects and technicians who do not desire greater integration with those outside of the office, ArchiCAD and Revit saves time and energy in simplifying tasks.
It is still early days. We have a while to go, but it is coming. There may be a day when you can't get away with not using Building Information Modeling software, because everyone else is. Things to look out for are structural and environmental analysis tools being built seemlessly into BIMs (green designers take note). Autodesk's Revit Structure allows this very thing to happen, but the strengths of these things are dependent upon the level of adoption within the wider construction industry.
'Adoption' is the key word here. The various software companies in the construction business really need to learn how to collaborate with each other and make their software interoperable. The present system means you have to export your BIM model for use with other software, rather than edit the same model. With it, integration is gone. The International Alliance for Interoperability (IAI) are fighting this point on our behalf. Check out their website to learn what they are doing.
There are legal issues to be worked out here too. BIM is quite a departure from the traditional paper record-keeping. Where paper drawings were the legal document, what is the legal document for BIM? The problem becomes even more tricky when various trades might be working on the same model, blurring the boundaries of responsibility. Good practice on this front is yet to be established.
Please pass me comments as I intend to keep this page up to date with the latest developments.
Matt Dillon San's blogpost has a more detailed, ground-up explanation of BIM. It is 3 years old, but it is still very informative.
A Mr Lloyd J. James has an interesting article on BIM. Being somewhat academic, it talks about the future of BIM.
4bim.com is a website dedicated to BIM, and is affiliated to HOK architects. There is so much here I don't know what to click on.
Heathrow Terminal 5 building project is an early example of where BIM is used extensively. Of note here is the special contract that was drawn up for a new, integrated method of working.
an Integrated Project Delivery guide (pdf) compiled by the American Institute of Architects (AIA) gives a detailed guide on how to manage project teams with such an integrated working method as BIM. If you're going to use BIM within a team, this is an essential document. It might be an American version, but it is still entirely relevant for the UK construction industry. It covers everything from team management to legal considerations.