A builder cries out for better BIM
I recently attended an informal evening discussion group that occurs every month in San Francisco, on issues related to BIM. The person leading the discussion this time was Dace Campbell, of BNBuilders. As a general contractor, his agenda that night was to cry out to architects everywhere about specific things we can do to make the BIM more useful to the construction phase.
Because he was an architect before he went into contracting (he still maintains his license), he is the perfect liaison between the two worlds.
You see, with any "collaborative" project, the design team should be sharing the BIM with the building team. This, in itself, is a radical idea. After all, our instruments of service have previously been pieces of paper with specific cropped views, which we make official by putting our stamp and signatures on. Then we cannot be held legally responsible for anything other than those pieces of paper. The CAD or Revit models we use to draw behind the scenes is our own business, thank you very much.
Because our industry has previously thought this way, we've fostered some pretty sloppy practices within our models. We do things that may look fine on the paper when we print it, but make the model difficult to use for the builders' purposes. If we stick to this way of thinking, BIM's full potential is badly wasted.
If we architects just keep it to our design team, the information can only be used for basic 3d visualization and coordination. But if we jump to the next big step and share the BIM with the whole project team, then it can be used for all these amazing things:
Constructability reviews
Scheduling
Sequencing
Cost estimating
Bidding
Ordering materials
Above-ceiling/in-wall systems coordination
Prefabrication
Commissioning
Operating & maintenance
But just sharing it isn't enough, if what we share isn't useful. So here is the little manifesto of things that BNBuilders wishes we would do, that would make all this possible:
Model it all - If it's not in the model it doesn't exist. Remember when your professor in architecture school told you, "If it's important, draw it. If you don't draw it, it means you don't consider it important?" Well now we're modeling, not drawing. Same rule applies.
Share the model - Share the actual source, not derivative extractions. Using a program like Riverbed allows changes to constantly be communicated out to the whole team without having to "re-post." This doesn't mean you stop using official Change Order or Informational Bulletins for changes during construction.
Assign Responsibility - Even when many people are contributing, make sure someone is responsible for bringing it all together and enforcing standards.
Level of Detail - Accurate scope, size, & location are far more important than lots of detail.
Model Standards - Practice good digital hygiene. Don't let people create repetitive partition types. Don't override dimensions.
Support Bid Packages - Make sure the "I" in BIM is real information.
Reflect means & methods - Model it like you'd really build it. If it's a full-height wall, pull the walls all the way up to the slab so they can get an accurate material takeoff. Don't model guardrails using the "curtainwall" tool.
Revisions - Manage change or it will manage you. Never change file names by adding dates to the end of them, for instance. If you want to archive a certain spot in time, save the files with the same exact naming into a folder that is labeled with a date.
Verification - Test early, test often. BIM should be accurate, above all.
During our discussion, we talked about the implications to the fee structure. If the architect is still hired under a fixed fee and is not sharing in financial benefits that the building team gains from these extra efforts, why would we bother? Why would I put in an extra hour to make life easier for you if my fees are already stretched too thin?
That's why the owner should be doing Integrated Project Delivery (IPD). The IPD compensation structure makes it so the design and building teams have one shared profit pool. That means the team can shift some of the fee toward the architecture team to put better up-front work into the model, so the whole team benefits.
If you aren't operating under an IPD structure and you know the owner wants a "collaborative" project, such that you'll be sharing the BIM with the builders, architects should ask for a larger fee. Mr. Campbell even said that he's been asked to speak to owners in support of this idea. A little extra time spent up front on the model will save a lot on the construction end.
