Revit Modeling for Navisworks Clash Detection

[BDR_Architect]

(I also posted this on the Navisworks forum but this seems like a Revit question too)

Our firm is currently in a big debate on how to best model our Revit projects (all disciplines) to take full advantage of Navisworks Clash Detection. We've been doing the Clash D. for a while but there is always situations where you're ignoring a bunch of clashes because "it's suppose to clash" (ie. Beams going through a wall, mech exhaust going through a ceiling over lab equip, etc.).

My question to everyone out there that has been doing Navisworks Clash Detection with Revit models is: Do you cut holes in walls (or ceilings) to allow for things that are suppose to "clash" so they don't show in Navis or do you continue to ignore those specific ones in Navisworks? Or is there something I'm missing here? I want to make the most of these tools.

All feedback is much appreciated.

[twiceroadsfool]

Well, heres what we do:

1. We dont clash *everything against everything.* We set up specific Clash tests to look at specific items. Structural beams versus Interior non load bearing non fire rated partitions doesnt happen, since theres no point. In that situation of course they clash in the model. The walls are getting built around the structure. So those two never appear in selection sets opposite one another in the clash detections that we run.

2. When clashes do happen that are unexpected (but okay, since those items "can clash" in the field) we approve the clash in Navis, and its fine. Subsequent tests dont show it as a new clash, it stays approved so its only an issue during the first clash review... UNless something changes pertaining to that clash. Also, if were "appriving" it, we'll typically make a note of why.

3. Some things we let clash for modeling efficiency sake, and then in certain clashes we approve them intentionally, but were looking at them. Fire Rated partitions come to mind. There will be dampers, and mechanical equipment of a particular variety AT the fire rated partition, but for us... We still model it as a solid partition. So when we run the clashes against the Fire rated partitions, we know were looking for specific items in EVERY case where something hits that selection set. As long as we see the particular items were after, we approve it. If we see a clash that doesnt have what were after, we dont.

Theres a hundred ways to skin a cat, thats just what we do here. :)

[BDR_Architect]

Thanks for the info Aaron.
Sounds like we do things similarly.

A good suggestion was posted from my Navisworks post:
http://forums.augi.com/showthread.php?t=113786

I guess I didn't think about making new Rules. Seems like a good idea. I will try and post my results.

[twiceroadsfool]

Yeah, the rules are helpful. But like i said, we set up specific tests that dont often include the Interior insignificant partitions. When you think about it, just about everything clashes with them. LOL.

[TroyGates]

We typically only run clash detections on floor, ceilings and roofs against mechanical, plumbing and structure.

[hkossila]

We create a 3d view in the revit model called Navisworks Export and set visibility to turn off what we don't need. Really all we are looking for is structure, shaft and fire rated walls. We use filters in VV to keep only rated and shaft walls on. We usually don't include the floor as we know things will have to penetrate the floor. We usually turn ceilings off, but will leave lights on - unless our elect sub is going to model those, then off they go in the revit model.

Also, when we are working with A/E consultants we ask them to set up a similar view with VV settings to show only these things, that way, as they continue to model they can just go to that view and export to nwc and don't have to think about it.

It helps to keep disciplines separate too, IE: Arch model, Structural model, and if there is phasing, we separate that as well.