BIM Design Build process

[moliva]

I recently went to a BIM discussion meeting for an upcoming project. The planning for this project is to have a fully coordinated set of drawings to be developed during design, essentially "shop drawings" of piping, ductwork, conduit, FP, etc that could be essentially be the construction documents when work is started and be dynamic to modify w/ any changes throughout design and construction process. The terminology started getting thrown around, BIM, Revit, IPD, etc.

When we got into it the real important aspects of this project goals there was an emphasis in having a quick and efficient workflow from drawing to fabrication (ductwork emphasis since that is mainly what I'm interested in). That being said it didn't seem to make sense for us to design and model using Revit since the mechanical contractor would have to turn around and make ductwork shop drawings from scratch since they do not use revit. What sounded more effective was to have a close dialog between Us (engineer/designer) and Sheet metal contractor to develop the drawings together. We'd first provide a schematic one-line layout of ductwork, boxes, diffusers. They'd create shop drawings, we'd markup and send back, they'd revise, and continue w/ this back and forth until the design was nearing complete and we'd see little additional changes.

Revit did not seem to be a very useful option in this case (ductwork and piping wise)...anyone see this differently? Any case for us as designer to spend a huge effort in producing a model in Revit that would help w/ this workflow?
Thanks,
Mike

[k.vaughn]

As the Mechanical Contractor both Wet and Dry, we would prefer schematic design drawings. We also prefer for the Engineer to sign off on the fully coordinated Shop Drawings before they go to fabrication.

Why waste your valiable Engineering time developing mockups that are essentially useless?

[m20roxxers]

Mostly due to that fact that what some people think is co-ordinated is not at all. The amount of projects in the last 12 months that I have been involved with have this same mentality.
I know many companies can co-ordinate, but alot more can't and say they can and at the end of the day RFI's come forth in their hundreds, things that weren't considered or taken into account come forward

And yet the poor subbies are the ones on site cleanup and making changes to others peoples work because everyone else is co-ordinated but one or two service disciplines, and more people have to get involved because no-one thought the model was worth investing into, what is the cost of one RFI??

I agree revit in many cases is not the best tool without very good end users, content and experience behind the subcontractors to do it. And yet I know of big subcontractor firms pushing revit MEP all the way, and again they're biggest issue is the designer doesn't do it properly usually due to the lack of understanding by the cad monkeys beating away on they're keyboards. Or worse they get CAD drawings how many software packages can automatically do a costing of a CAD drawing vs a Revit, CADmep model? Especially when you can save a contractor with the right software many days, and charge for the information you are providing.

People then bring up we don't others to trust our information, if this is the case then don't be a designer in the first place, if you can't trust your own firm to come up with the right information I wouldn't want to pay them for their services no matter how cheap. Everybody is dodging responsibility and the benefit is by taking on that responsibility we get paid alot more and we just need a good QA process. Trying to charge people for 3D models that a firm takes no responsibility for is what people are trying to do and no wonder why we get projects that are purely verification of systems that we model up based off others drawings. Or a model up of someone elses design. If the other consultants don't do it we get paid for it, they still maintain responsibility since it is built off their drawings, and we get the next project from the client as they know we can do both and therefore no double charge.
Thank you very much

The other thing to understand for many firms is that 3rd party 3D MEP tools are just as effective and we don't always need intelligent information, a spatial model for clash is more then enough and many other tools can do this and fabricate alot faster.

However using CAD is just silly these days, it takes just as long either way and you get 10 times the amount of information. I do not see any situtation with a good team to use CAD at all, and this is the same for the sub-contractors who have got this up and running.
However I will point out that at very early stages we will only develop portions of the model in area's of change and use base runs with no connections till things settle down. But we model all pipes people have this option where they say "Don't worry about anything smaller then 20mm there is no point." Well they're isn't untill your in a hospital job and you have 10 pipes/conduits 20mm each bundled then all of a sudden someone realises whoops.

With particular contractors we are developing systems to allow us to pass the model back and forth in a collaborative agreement, we have this process in it's early stages much much better then passing a linked revit model (which is still better then CAD) as long as you know and trust the team and have the right procedures standards and trust.

Sorry I just came back from a meeting yesterday with the same thing, bad news is one of the services consultants we are working with aren't doing BIM just CAD, they aren't interested in all this Navis stuff the client wants. Good news the consultant is paying us to build they're model off they're drawings, and for us to co-ordinate it and tell them where they need to sign off for the changes. So they take the responsibility, we do the development with our services and we get paid. Can't get better then that!!!

[m20roxxers]

This is not a rip on anybody, this is just to point out, that is it worth doing models yes it is!!!!