I don't know that this is the right place for this question.
I work at the contractor level and I seem to be running into contstruction managers that think we need to be using Revit and submitting files in Revit to get various trades coordinated. I've always thought that was Navisworks job. As far as I was aware Revit does not involve clash detection and Navisworks is a much better tool to be used for 3D coordination.
I'm just looking for feedback. Is Revit intended as a coordination tool at the contractor level or is Navisworks much better suited to perform this feat? Does anyone know of any discussions/comparisons of these two products?
Well, on the Engineering side here and using Revit, It is my understanding that Revit is a design tool and Navisworks is a coordination tool for management. Revit does have clash detection, just not insulation, specifically. That is one of the big features about Revit. Yes, we coordinate everything, all trades. anything that is modeled in revit, I can coordinate it.
I have not used navisworks, but I understand that it is not suited for what I do (Modeling and creation of construction documents). In the Ideal world of a construction project, all trades would utilize the same program in order to work seamlessly.
I am the slash in-between.
It seems to me that Revit is more useful on the Engineering side and Navisworks is more useful at the construction manager level working with contractors developing specific installation drawings.. aka shop drawings.
It appears to me that Revit does not do the type of design I for example would need. i.e. Can it hydraulically calculate a fire sprinkler system? Can it generate a fabrication stocklist of that piping system? Can it generate a cost report and handle warehouse inventory based on the stocklist? Can it generate weld diagrams automatically for the fabricator? Can it tag the shop drawing automatically so those fabricate pieces can be located in the shipment of piping and installed in the field? I would assume Revit likewise does not actually perform any engineering of ductwork systems or electrical systems. Does it perform required calculations for sizing of ductwork? While in the future it may indeed do those things so that everyone can use it seamlessly. Which brings me to my point that Revit is not a good tool at the construction manager level for coordination between trades and that Navisworks is much better suited as it can read files from each trade.
The problem I have experienced is Construction managers try to force everyone to be "seamless" and use a program that cannot adequately do what we need it to do. And the real reason I see them wanting it is because they want a smoother project and they see that utilizing 3D design (as I am calling it) in the coordination process is the way to go about it. Which is fine and I would agree. But they don't seem to see the difference between Revit and Navisworks. It would appear to me that Navisworks should be used "at the jobsite" to coordinate the final installation and Revit should be used at the Engineering/Architectural level as the foundation for the more specific installation that happens on the jobsite utlizing Navisworks.
Oddly I cannot find a comparison anywhere between the two programs.
You are correct that Navisworks is not used to create construction documents. Rather to overlay various designs from individual contractors into one 3D model. At least that is my understanding of it.
I think you are very close. The issue with Revit is that it is more for MEP engineering and design than Shop drawing production. When i create a long run of duct or pipe, I am not going to break it up into sections as it would be built, shipped, and installed. I CAN DO THIS, but the system wasn't built to do this very quickly. I can schedule every item placed in the model, and add up cost. But then, I would have to look each item up, calculate material cost and installation cost, then add that amount to the "Cost" field for each item. Like I said, it can do it, but it isn't a tool created primarily for this.
It does do duct and pipe sizing, but engineering these systems is more complicated than what revit makes it. it doesn't do some calculations (Vent sizing, Refrigerant System calcs, Gas or Compressed Air sizing or calcs).
I was under the impression that Revit and Navisworks operate seamlessly, and they function well in exactly the manner we are speaking of (Engineers and Architects use Revit, Construction Managers and Contractors use Navisworks). I had a large project where I modeled most of the building in Revit, but the Contractors RE-MODELED everything thier way in Autocad MEP 3D, and sent submittals to us in 3D. I couldn't be more upset, I had to learn Autocad MEP just to review thier model and look for interferences. Bad Idea. Navisworks must be better than that.
My 2 cents.
I am modeling HVAC and plumbing in Revit for a Mechanical contractor, while there are other models being created, .dwg format, for the different displines of the project. The GC is using Navisworks on the jobsite for 3d coordination and to run clash detection.
What I have learned is 3d coordination/clash detection with .dwg models and .rvt models is near impossible to do with just Revit and AutoCAD. The firms creating the .dwg models have to export to .ifc files for me to be able to manipulate them in Revit and run clash detection correctly. Sounds easy enough, but when importing .ifc files into Revit MEP the software kicks back 100s of errors causing the deletion and disconnect of may elements. Having Navisworks fort the overall clash detection so far seems to be the way to go.
All in all, different softwares, different file types, seems like anyway you go, you will lose information in translation which defeats the purpose of 3d models and coordination.
Revit (or similar) is needed to create the model - you cannot "create" anything in Navisworks. The advantage of navisworks is that you can import (almost) any type of 3D files and run clash detection. Navisworks will also print out which items are clashing using ID references that correspond with Revit - this can make it easier to find.
Essentially IMO all consultants and contractors should be using Revit to modell with. The BIM managers (within the office and/ or external as part of the project team) should be using Navis works to run coordination checks as well as visualizations - including 4D and 5D animations.
Revit is not a tool for contractors nor is it intended to be. Autodesk's intended workflow is for engineers and architects to use the revit family to engineer/design the project and contractors will use Autocad based software to construct the building. Navisworks is the go between to coordinate and visualize the models.
You can view a interview with autodesk on the subject here. http://www.eccadcam.com/mep_industry_trends.shtml
I think when we talk about "Autocad", we must clarify whether we mean 2D Autocad or 3D Autocad. Revit and Navisworks are built for each other, Autocad MEP 3D is a serious attempt at BIM, but is built onto a platform that wasn't intended for modeling. Cut sheets and shop drawings remain a 2D Autocad production, which is one of the issues with incorperating BIM thru ALL trades.
Contractors here (in Australia) use Revit to ensure coordination, and to keep the flow of the model through to the client - of the bigger contractors they have been more keen on Revit than quite a few of the consultants. If, for example, a contractor wants to change the fan coil unit used (different manufacturer - most probably different dimensions/ cost/ energy usage etc) then they will need to do this in Revit otherwise you will not have a correct BIM model at the end. Shop drawings etc will still be done in (most probably 2D) cad, although we are working with contractors here ATM to create duct fittings in Revit that they will be able to plug directly into their CAD/ CAM machines.
You mention using Navisworks to develop shop drawings. How has your experience with this been? I am assuing you are talking about coordinating the models in Navisworks and each individual trade going back to there models and using those to create shop drawings. Have you ever created coordination drawings from the coordinated mocels?
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