Every now and then I get asked, "So Steve, how long before we just deliver a model for construction instead of drawings and specifications?" Since my nickname is Nostradamus, NOT...I smile and reply, "Next week...next year...next decade?" It usually turns into a nice discussion, all off topic from training, and eventually we have to get back to work!
Just the other day I was speaking with a few students and one of them is working on a project that is under construction and it started out in Revit. Typical construction practice, drawings and specification are the contract documents and the model is available for reference/information. So in this wild future where someday we will use the model more than relying on drawings...turns out this wild wacky future is the past, as in it has already happened sort of.
The subs have apparently been using the model more than intended and ignored the documents, where they shouldn't have, and that's created some trouble. Turns out that walls in the model don't all represent the actual construction conditions, meaning they don't all go to the underside of the deck above etc. The model is sufficient to provide complete documents. The documents very clearly define each wall type and provide the requisite detail to know how to install and finish each wall. Trouble is they didn't pay all that much attention to the documents. They liked seeing the model and those walls aren't the same as the docs. Uh oh!
So the sub-contractors preferred to see the intentions in the model, rather than by studious review of each and every relevant document. My reaction? No kidding! I would too! Why wouldn't they? The contract says they were supposed to but they didn't. When I heard all this I couldn't help but think about every time I read or heard comments about custom arrowheads, where leaders start on multi-line text, the appearance of section and elevation heads, hand-lettered fonts, title block styles, the good-old-days when drawings were art, elevation depth planes, dimension styles and others.
Drawing and documents are a means-to-an-end but they are also a language and not everyone is comfortable with this arcane and, a bit, stuffy language. A model is more democratic because you see it, I see, they see it and practically anyone (who has walked around or inside a building) understands what they see much much faster.
I've been thinking and saying, respectfully, to people for a long time now, "Does any of those things matter when drawings don't matter?" I get laughed at or sometimes seriously angry attitude in response. If the model matched the documents there would be a different story. No formal expectation that the model would reflect the documents precisely existed. Yet the contractors inferred that it did because the model exists. The model IS more important, not in the future, now. We are still in transition, more like confusion, but it is happening here and there, all around us. The sooner everyone figures out how to live in this wild frontier the better.
5 comments:
Fabulous post Steve. Once upon a time I wrote something about the "I" in Walls and it was really motivated by similar thoughts.
More than asking about functionality to make drawings more pretty (text tools come to mind), users should be demanding tools that make difficult conditions easy to capture in the model. Sometimes you end up having to do something in 3D and then do something completely different in 2D, at which point we say to ourselves: Just do it in 2D because that's our deliverable! That leads to the issues you just outlined, especially if a contractor was going to use the model for take-offs.
Revit is great (in most cases) at letting us capture information in 3D and reflect that in 2D. But there are a lot of cases where what we capture in 3D is not available to be extracted in the way we want to see it in printed form (ex: top conditions of walls, fire rating, etc.), so we abandon the 3D and "draft" it in 2D. Until we get around this issue, it will be very difficult to have a truly BIM deliverable because we need both the 2D and 3D deliverables. I don't think the 2D representation will go away anytime soon and we'll be requested to provide both. At the moment, this means a lot of extra work.
Good point well made. I do agree with Dave above about 2D though. In order to model everything (steelwork holes, bolts, washers, wall ties etc. - I work in structures) would require many times the effort we invest now to create our "deliverables" and communicate intent. Revit and hardware needs to evolve a lot more - we are talking several magnitudes - before a model will be a complete package. When the client does understand the limitations of what details or elements are omitted however - the model can be used very effectively.
Since I'm not one, I get frustrated by Architects who regard BIM as a tool to generate better documents.
It's not about documents, which are just one device to enable communication & analysis of the design!
But then, even a powerful BIM tool like Revit is so removed from how buildings are actually built (in how it handles components, connections and workflow) that I doubt we can really "trust the model" until the next generation of BIM tools arrive.
Robin-
Its very important to remember a few things in that regard: There is BIM, then there is BiM (stolen from Kelly Cone).
BIM is a process, one that very few of us are really doing. Having said that, one of the TOOLS of BIM (Revit) has aided many of us and helped us leverage PARTS of BIM to make BiM.
But the fact remains- much like in Steves example- that the contractual obligations are what rules. And for most offices, that means 2D documentation and deliverables.
I had an end user that modeled every single Tenant Demise wall to 8 feet tall. Was she wrong to do it? Not in the least. It showed up correctly on every document it showed on (no bldg sections), and all of the information was properly conveyed.
Would it have taken MUCH longer to attach them all to the underside of the roof? Perhaps not. But it wouldve taken longer, considering you can draw them at the height of 8 feet and never bother with the roof. Roof attachments sometimes error out, people detach, erase, move, unjoin, disjoin, forget, whatever... And if the Model/quantities arent going out-of-house, its a non value adding process.
Now, thats ALL out the window if the model leaves the house in any way shape or form: Walkthroughs, Navis, for contractors, etc.
But the best thing we can do is to EDUCATE all the players in the industry, that JUST BECAUSE a model is used, does NOT mean the model is fully articulated. It also doesnt mean that model is free.
In a perfect world we will all hand models over for free, and leaves the drawings by the wayside. But in a perfect world we will also sit around a virtual campfire singing kumbaya, and architects and engineers will sing each others praises all night long while contractors write us adorations for our work. :)
As mentioned above, Revit is very good at creating General Building Components, walls, roofs, floors ect.. and very good at creating the 2D documents that go with them. I find it's not very good at modeling the condition specific detailed stuff, sure you can do it through in-place families, but you will wear your mouse button out with the number of clicks you have go through.
I find it interesting that the mechanical cad industry has realized that a fully parametric constraining cad system works well for some things, but not everything. A more direct modeling manipulation approach, this kind of sketch up like pushing and pulling of the model works better. You look at Space Claim, Solid Edge's synchronous technology, and even CATIA V6 has introduced direct manipulation to their elements, and you think man wouldn't it be nice to have that ability with a Revit Wall. As always the AEC cad world seems to be a few steps behind the Mechanical world. I will say that the new 2010 massing tool was a first step to this approach, but it is a far cry for the easy manipulating environment of space claim.
Post a Comment