Renovation Projects and CAD plans. Best Practices.

[Charles.Ball]

How is everyone handling renovation projects that have CAD drawings? Are you using the CAD plans in your Revit model?  

For example, say you have CAD plans of a building but you are renovating an area in one wing. Do you link in the CAD plans, trace the project and some surrounding area, and then turn off (or remove them).  Or, do you model only the area you need and leave the surrounding area as CAD?

I believe the first choice is the preferred method, but I am getting a lot of push back to do it the other way. 

[syman2000]

It really depends if this will be on going project or this is one off. If it is only one off, you would build what you need and leave other out. If this is continuous where client will require additional service, I recommend building the rest so next time you already have the base model built.

Also budgeting becomes important. I know clients won't pay to have everything built. So why waste money building something they won't use? I only see the extra work as way to market your firm ability to potential clients. Having VR and walkthru the space makes it compelling to build the rest of the model.

[barthbradley]

Either way. CAD Links have the same Visibility and Graphics controls that Revit elements have (sometimes more because of Layers).  If you are uncertain, leave the CAD Link in the Project. You can always remove it, if need be, at anytime down the road. 

[martijn_pater]

Your question generalizes two implied workflows, so you will most likely get generalized answers along the lines of 'whichever suits your (clients) needs'. Probably not what you are after...?

[Charles.Ball]

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@martijn_pater wrote:

Your question generalizes two implied workflows, so you will most likely get generalized answers along the lines of 'whichever suits your (clients) needs'. Probably not what you are after...?

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No, not really. Actually we are in-house. We don't have clients. We are an in-house Arch/Eng/PM firm for a hospital. 

How can I change my question to be more specific? I am trying to push the "no CAD backgrounds" in the drawings as it seems it's harder to control the visibility of things across the disciplines if they are in CAD. The current CAD plans also have some problems with things being on the incorrect layers.  

It doesn't make sense to me to have to go to the CAD plan, put everything that is going to be demo'd on a layer so it can be controlled in Revit, then draw walls on top of that, make those demo in the New Construction phase. Then leave the surrounding area as CAD. It seems easier just to trace the scope and some surrounding area all in Revit and then turn the CAD plan off. 

[_Vijay]

better the clean CAD first..as you need.

[RobDraw]

To me, you've nailed the most important aspect, time spent wisely. Since the CAD needs work, why not just put that time into generating a working model or models? That's going to get you the most bang for your buck moving forward.

[martijn_pater]

Since you're an in-house firm as you say, I think in the long run you might benefit from having your 'house' built 3d in its existing situation and just model in the changes going forward and ie. also having maintenance info etc. in the model. Maybe that is a bit too much of an ideal though, but perhaps something to work toward.

What you could try maybe is to model the buildings/part of buildings from the

2d existing plans for ongoing projects and maybe premodel parts up front for near future changes etc., but then also linking it into a combined model which would grow over time... although that might become a somewhat different goal probably...

I'd go with moving to 3d/BIM anyway and/or possibly using pointclouds even. Also you could exploit phasing functionality fully in Revit. Whether or not you leave the CAD as underlay is not as important imo, but I would refrain from drawing everything in ac and revit...

This might be somewhat based on an idea of the (scale of) projects you're doing, ie. hospital wing 😉 The smaller the scale you might be more inclined to use autocad more I suppose, since for larger projects the added value of a working 3d model would become bigger also.