So here we are a BIM symposium in snowy Abbotsford, my home town. It is snowing steadily here,with about three inches on the ground as I carefully drive to the other side of town. About 20 others also managed to make it here; surprisingly to me, about half are contractors. The rest are a smattering of 1 or 2 architects, structural or electrical designers, and so on.
What is BIM?
Bob Heyman of Summit BIM introduced us to BIM [Building information model] by describing three stages of design: Pen - CAD - BIM = horses, cars, airplanes.
(During the break, Mr Heyman and I recalled our early involvement in the Vancouver AutoCAD User Group, back in the late 1980s.)
BIM is not software; Revit is an example of software that enables BIM, although he has found that some clients use Revit to create just a model (a graphical representation of the building), but not take its data further. The "I" (information) in BIM is the most important part. The data is used for the building after it is designed and built -- mostly of interest to owners.
(The purpose of this seminar is not so much about introducing BIM, naturally; the aim is to sell licenses of Revit.)
If you can model it first, then you can build it right -- better than running into problems in the field with trad methods.
While it takes more time upfront to prepare the model, the architect will have savings during the contract administration phase, which is typically 25% of the project cost.
Multiple engineers working in their own models, such as architectural, structural, and MEP (mechanical, electrical, plumbing), and then bring them together. One model, all deliverables. View the same drawings in many different ways through views, such as fire plans.
Able to do analyses,such as structural (with an external program), sun analysis, mechanical systems, building performance. Choose what you want to get out of the model before you start. You cannot just decide to do building analysis; have to decide to do this ahead of time so that the data is entered as the design is created.
As a consultant, he finds that many architects want drawings to look exactly the same as before, such as specific lineweights. This is a chance to ask, "Why do we need to keep doing things the same way."
Cost of handing on drawings:
- should not charge just because they come from a BIM program
- handing on drawings = no charge
- handing on model for facilities management = charge
The CAD expert is not the BIM expert.
The structural engineer is Michael Sullivan from Bush Bohlman + Partners. He is showing us quite a few projects that are add-ons to existing buildings: add-ons to airports, hospitals, community centers, and so on.
The toughest one was the new Prostate Cancer Center at Vancouver General Hospital. He first modeled the interface to the existing building, and then figured out how to fit in the new structure. The tricky part was avoiding underground tunnels, typical for huge hospitals like VGH. Nevertheless, structural design for a hospital is easy compared with MEP, which really shines with a BIM modeller like Revit.
The construction company used the Revit drawings to locate their cranes, and determine the number of concrete trucks needed -- based on the quantity takeoff derived from the model.
Because he knows that his firm will be doing more buildings for VGH in the future, his staff is already modeling existing drawings in Revit -- so that they do not need to hunt down paper drawings made in the 1960s at the start of the next project.
A building he designed for Bermuda was project managed remotely using Revit; he didn't need to fly there (darn!).
(Sitting in front of me are two attendees from the regional hospital administration. They are wanting to implement Revit, but since healthcare in Canada is run by provincial governments, the implementation process is slower than they like.)
Graham Hyde is now talking about Revit MEP. Clearly, the big advantage is the ability to check for conflicts. No more columns through heating ducts.
A question about coordination between "subs" (sub-contractors). You can install a piece of Autodesk software onto Revit that allows social-media-like real-time commenting between designers.
For the contractor, they can see problems in the Revit model before going onto the site. For the client, they will be able to use the Revit model for facilities management. It's all about data being passed around from phrase to phase.
He is showing use a project he began a week ago, doing the MEP for the third floor of a new school building. (It does seem odd to be designing a new school for our city, when the school board is looking to close four others.) He switching between Navisworks, which displays all of the project's models at the same time, and Revit MEP.
I am interested to hear the kinds of questions attendees will have. Most of the questions, so far, are asking about coordination. In answer, Mr Hyde showed a $2 billion hospital project from England in Navisworks. Nine stories. $1.5 million alone was budgeted for MEP coordination. He pointed out the plastic drain pipe from a simple sink. Because it relies on gravity to drain the graywater, the pipe's route forced an HVAC duct down a couple of inches, which then forced other lower pipes to move.
Q: Do all consultants need to be on the same software, need to use the same model?
He points out that he, as an MEP engineer can notice errors made by other subs, and then redline them for correction by the approved designer.
Thanks to Wes Macauley of CHP Architects for inviting me.
[Disclosure: The BIM Symposium provided attendees with lunch.]