Project in Revit and AutoCAD

[aryak351601]

I'm starting an expansion project for an existing complex that includes four new buildings and a renovation to an existing building. The existing complex was completed last year, and all the existing drawings are in AutoCAD. The architect for the existing complex is also working with us on this project. Two of the new buildings are almost exact copies of a housing unit prototype used throughout the complex which are completed in AutoCAD. The majority of the details that we would need are already completed in AutoCAD as well. We don't want to model everything since most of the work has already been done in AutoCAD, but we want the construction documents to look like one set.

We thought about modeling the two completely new buildings and the renovation in revit and keeping the prototypes in AutoCAD. We would then link in the AutoCAD files and print from Revit. The big problem we would have is populating our schedules in Revit.

Any suggestions or comments are appreciated.

[Craig_L]

Its not uncommon to do blended programs. The scope of what you need to do is my only concern for you. What I have done in the past with any work completed in CAD is to have a CAD-Links model and this is linked into your main model with the cad links placed in it properly (obviously) and this allows you to unload the entire cad links model when its not needed which speeds up things a bit.

In addition to this, we use the revit title blocks for cad links, this allows the sheets to be scheduled and revisions to continue on properly in revit - although this may not affect your documentation. Just to clarify what I mean there, link in the model space CAD work and not the paperspace so you need to place a view of your CAD plan on a sheet as you do with any revit view.
All of the details etc can either be brought in to revit detail views, or simply linked as CAD drawings, I would recommend the latter because importing CAD details into revit drafting views tends to have issues with text, and some linework goes bizarre - in short there is re-work involved with bringing 2D details into revit drafting views from CAD.

Im not sure why you would have problems with populating schedules, are you scheduling items out of your existing buildings? All of the new construction will be modelled so its not going to affect that.
Other than that, it just takes a bit of organisation to keep your CAD links up to date but no different to XREFs, and you can have a reasonable amount of control over your links (make sure you link them in the correct discipline this gives you additional visibility control)

[david_peterson]

First question I would ask in a situation like this is what does the owner want?
When you're done with the project are you going to have to convert these to Cad anyway?
Also remember that when you link cad alot of your text, leader, dimstyles, hatch patterns, are not going to look any where close to what they did in Cad.
So you're drawings are going to look different anyway. IMHO it's best to keep Cad in Cad and Revit in Revit. Print Cad from Cad and Revit from Revit. You'll spend a lot less time trying to "fix" stuff that doesn't look right. Take the hit that your drawings aren't going to look like everything was drawn by the same person. I tend to create dummy sheets in Revit for anything I've left in Cad.
But again, my first question would be does the owner want the end product in Cad or Revit? And is there a standard that needs to be followed. Depending on the answers you might spend as much time trying to convert the drawings from Revit to Cad as it would take to re-draw the entire project in Cad. At least I know that's the case for one of my current projects. I'm still trying to get the higher ups to understand that we'll be spending (by my guess) 500-700hrs converting the project once ti's done. And I might be short on that.
Best of luck