Tuesday, July 7, 2009

Interview: Building Information

Building Information Management (BIM) systems allow building contractors to manage all the information about a building project. Without BIM, complicated structures like Frank Gehry's Walt Disney Concert Hall are nearly impossible to build. BIM also improves the economics of building less complex buildings.

disney hall exterior close up 5

Chris Chebegia studied Construction Engineering Management and now manages (BIM) systems for building contractors. I chatted with Chris about how he uses BIM on construction projects.


Steven Damron: How long have you been using BIM?

Chris Chebegia: I personally am not a modeler or designer. I manage modelers during the construction phase of a project, and this is my second large scale commercial project. Four years total experience for me.

SD: What was your favorite project?

CC: My previous experience with BIM was at the Walt Disney Concert Hall, and I would call that my favorite project to date, with or without BIM. However, BIM made it an extraordinary project to be part of.

SD: Describe how you work with the modelers and designers.

CC: My experience has been in "design assist" - where the design is partially complete, and the model is being used to check the coordination of the design. Typically, the different disciplines of the design team do not coordinate their drawings through the traditional design process. BIM modeling makes uncoordinated design stick out like a throbbing sore thumb, as you see the design busts or conflicts graphically when the different design disciplines are combined and overlayed in the model. We then fix the conflicts prior to construction, thus saving potentially millions of dollars and months off completion dates for large projects.

SD: So BIM helps pull together all the information from all the parties in the building process?

CC: Correct.

SD: Did Frank Gehry get directly involved in the Disney Concert Hall?

CC: Yes. And Frank Gehry was one of the first architects to use the modeling and BIM process. He is not much of a computer guy himself, but he definitely supported the use of the digital model to convey his design intent. He adopted and modified for his use an aerospace engineering modeling program called CATIA, which had never been used for architectural purposes. I believe that program has served to better the traditional BIM models and processes that are more commonly used in architecture and construction industries, like AutoDesk (AutoCad, Revit, and other 3D programs).

SD: I imagine many of Gehry's buildings would be impossible to building without BIM. How does BIM help in less complex projects?

CC: That is correct. I was told that without the technology of 3D modeling, the Concert Hall could not have been constructed to the accuracy of the design intent. We actually set large steel members in place at Concert Hall based on the laser coordinates set in the field and lined up with cross-hairs that we established on the beams.

Regarding more simple structures, the modeling program helps to coordinate MEP (mechanical, electrical, and plumbing) like a dream, because you see all members to scale, in 3D.

SD: There must be a certain size or cost level below which the overhead of BIM is too expensive.

CC: Modeling may not be as cost effective for smaller projects. It just depends on the owners needs. For example, we are up to renew our licenses here on seven workstations, and we are looking at more than $30K in software licenses alone!

SD: What do you see in the future for contractors building large structures? Can BIM get better?

CC: My collegues and I would tell you that BIM absolutely is the future of design and construction. There are even machines now that download BIM data to survey equipment that can actually robotically layout reference points in the field! This equipment is still being tested and perfected, and many contractors don't trust it yet, but it is to design and construction what the Internet has become to the world of communication.

Regarding improving on BIM, yes, there are many things that still need to be improved, and integrated between the design side and the construction side. One major issue is getting City approvals on changing models. There needs to be a way for a BIM model to be saved, marked as a "approval copy", and sent to the authority having jurisdiction for record. There also needs to be a way for inspectors to track changes in the model, not just on printed docuements. These are things that involve bureaucracy and will take time to change. But the software has to be there first.

SD: You always seem very excited about your work, like a kid with a new lego set. What is most fun about your job?

CC: I really enjoy solving problems. There is always a new issue to overcome on a construction site. You can never anticipate what a day will bring.

SD: What was today's issue?

CC: Today the fire marshall was here and not happy with the egress (which changes hourly). So we had to revise our work plan for the rest of the week, re-strategize, and move on. Then the chief inspector was here asking why we did something different than the way the drawings showed it, so we explained, and have to re-model and submit details for City approval.

SD: I've never had those problems at my work. Is there anything else you want to tell the readers about BIM?

CC: Ha! I will say this: Attention! If you want to make a ton of money, travel the world, and call your own shots (as long as you don't mind long days staring at dual screens), then get some AutoCad and 3D modeling training and become a modeler. Talk about high demand! Those guys are at the top of the world right now.

SD: Thanks very much for your time, Chris. See you at a large construction project near me soon!

CC: You are welcome for a first class tour of Tivoli Village in Las Vegas whenever you wish. See you soon!

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