Link multiple Floors CAD to Revit - Best Practices

[Anonymous]

Multiple Floors CAD

I got CAD file of a building look live above. I want to create model of each floor of the building in Revit so I need to link CAD to Revit.

As there are 7 floors, how should I link it?

Should I link CAD 7 times for each floor? How can ensure that each floor is correctly aligned?

[ennujozlagam]

@Anonymoushello, if they are not typical floors then you need to link them one by one and don't forget to tick current view only (per autocad file). you need them to move the autocad file each floor to the intersection (as reference points) of two gridlines (horizontal and vertical) to 0,0 insertion points so when you link the cad files you can use the positioning : auto - origin to origin. thanks

[ToanDN]

Wblock each floor to a separate DWG and they better have the same 0,0,0 s that you can link them to each level in Revit origin to origin and they line up without extra alignment.

[Anonymous]

Yeah, floor plans of each floor are not the same except where columns are placed. Thank you for your suggestion, ennujozlagam.

Now I have to find a way to separate floor plan CAD, any ideas?

[Anonymous]

Okay, let me try with WBLOCK, ToanDN.

[Anonymous]

I have tried to export each floor DWG using WBLOCK. I also set base point and re-locate UCS point.

But when I link CAD into Revit (with auto-detect units), the linked CAD is so small. So I select the linked CAD and go to Edit Type in Properties palette.

Then I re-set scale Factor to 1. Now linked CAD is proper sized but it is far from origin. Any thought to correct this?

[ToanDN]

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@Anonymous wrote:

I have tried to export each floor DWG using WBLOCK. I also set base point and re-locate UCS point.

Don't do that.  After you WBLOCK to a new file, open it and physically move everything from a known corner of the property lines or of the building to WCS 0,0,0.  Do it for all 7 of them.

But when I link CAD into Revit (with auto-detect units), the linked CAD is so small. So I select the linked CAD and go to Edit Type in Properties palette.

Then I re-set scale Factor to 1. Now linked CAD is proper sized but it is far from origin. Any thought to correct this?

When link DWG in, choose the proper unit (inch or whatever), not Auto.

[ennujozlagam]

@Anonymous hello, check your autocad DDUNITS change to units you are using before you link. thanks

[Anonymous]

I got to go out now, but I will try that, thanks :3

[ennujozlagam · Accepted solution]

@Anonymous hello, here we go a simple screencast. thanks

[ennujozlagam]

@Anonymous hello, just to check have you resolve your issue. thanks

[Anonymous]

I'm trying out. It's just I only have Revit around at office.
Look like this solution sholud work fine If CAD is not subject to change. Fortunately, it is the case this time.

[ennujozlagam]

@Anonymous hello, even though your autocad change the design and your insertion point still the same there will be no issue when link cad into revit. thanks

[MuirEng]

Hi, I like to suggest a different approach, that might work for you. 

We get CAD like this all the time and but we are now 100% Revit workflow, just electrical design.

What we do in this case is drop the entire CAD file on level 1 and then create multiple level 1 views, each cropped to show a different area of the CAD. These we then name 'Main Floor", "Second Floor" and so on. Our devices all live on level 1 in the model. So devices on separate floors are separated horizontally in the model, not vertically.

This is of course, not representative of reality but it leads to great plans and lets us use pretty much all of our content and processes that we use for full blown 3d Revit in Revit out work. Sure beats the heck out of going back to AutoCAD. And we can take new updates from the architect and pop them in painlessly. If you split the file up and lay it all out then you'd have to do that every update.

For what we do this works really well.

Let me know if you like the idea!

[Anonymous]

If Revit sees floor stacked horizontally, how do you take care of fitting equipment that lay though multiple floors vertically like Bus Duct or conductor cable in Lighting protection system?

[Anonymous]

Thank you everyone, I can do it finally.

I mostly follow what ennujozlagam has suggested on the screencast. Except that I use WBLOCK to save a floor DWG instead of delete all unwanted floors (and then save DWG). Because if I use DWG from deleting method, Revit returns warning "Geometry has extents greater than 1E9". I'm sure how it is related though.

[MuirEng]

In reply to Jack, the answer to the question two posts up is that for our typical projects we do not have any need to fit equipment through multiple floors, so this method works quite well for us. I realize it may not be appropriate if there is a need to accurately model in 3d.

[MuirEng · Accepted solution]

Hey Jack, I forgot the whole story. The method I described usually is fine for us since we don't have elements we model through multiple levels, usually. But if we do then our process is slightly different, but still faster than the method described in this conversation.

We link to the CAD file (not import) and then place one copy that link at each level in the model. The next step is to shift them all so they align vertically, and the last step is to crop each floor plan to exactly the same coordinates in x and y. Each floor plan has a different view depth (z) so it sees the correct level.

This way the work can survive an update to the .dwg without a lot of rework and it skips the need to write out each level to a file and separately link each. 

You might want to experiment with this method, but it sounds like you were successful blocking out each level to a separate file.

[Anonymous]

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@MuirEng wrote:

We link to the CAD file (not import) and then place one copy that link at each level in the model. The next step is to shift them all so they align vertically, and the last step is to crop each floor plan to exactly the same coordinates in x and y.

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How to make the copied CADs also modified when the original linked CAD is modified?

This method looks like the best practice so far though. 

[MuirEng]

When a linked CAD file instance is copied  you get another linked instance. An exact duplicate. The only thing different is the position in X,Y,Z

When the original CAD file changes then everything on all floors will update as soon as it is reloaded. Clear?