Rebuild - Link Existing Model?

[barrie.sharp]

We have a property that is so bad that it's being demolished and we have to put something similar back up as it's end of terrace. Finally I can draw a design rather than working on a refurb.

Since the whole property is being demolished, should I keep the old building in the existing phase or just split them into two files and link the existing back in for documents since we need existing bits for planning and I want one document set.

Because we are working to Regs, I have a whole new set of levels with 'NEW' as a prefix so that I can tweak their elevation. It would be less confusing and a little less risky to get rid of the old.

Any advice or prewarning of pitfalls?


PS. I also get structural warnings about beams on a non load bearing wall, only the walls have been demolished!!

[bregnier]

For projects that are truly demo'd down to slab (or more), IMO it's actually easier to do an autocad (or drafted Revit) demo plan and link that in - why bog down the model with superfluous information, and spend extra time doing an existing model? The only issue you might have there is that it seems like you might be trying to replicate what was there before, in which case a model might be necessary.

Breaking it up might be more trouble than it's worth, however - phasing works very well and this would avoid issues like which model keeps site information and remaining components like foundations, pads, etc. It's always a better idea to mark things as existing rather than new, so why not take the old levels and call them (E) First Floor Level, etc, and then put them in a dedicated workset that's off by default? Then use regular office standards for the new levels. This would achieve the same freedom you want and wouldn't complicated things with a linked file.

[barrie.sharp]

...so why not take the old levels and call them (E) First Floor Level, etc, and then put them in a dedicated workset that's off by default?

Great idea! Never considered that having never used worksets but this seems like a good place to start using them. Would you stick the existing on a workset too to get it out of the way? It still seems to interact with my new model despite being demo'd.

[bregnier]

In my experience that shouldn't happen if phasing is set up properly. Were the beams created in the existing phase and then moved to new? I'm not sure how beam hosting would work in that situation. I don't think using worksets to control existing model visibility would solve any problems with hosting you are having, and would likely confuse people as it's duplication of a control.

[barrie.sharp]

The beams were certainly in the new phase. I had drawn my external shell and set the walls to structural. I had an opening on the ground floor and placed an RSJ to support the wall above. Revit warned me that the wall was not structural and asked if I would like it set to bearing. I was sure I had set the walls to bearing so I used the warning dialog to find the culpret. It wanted to open a new view to show the object and to my suprise, I opened a 3D view of the existing phase/model. I hadn't set the walls on the existing since it was a representation of the building for documents and I would re use alot of the details/families which made it worth putting together.

It seems that the existing model is still there and demolishing it has made it invisible but not gone, so new geometry is still checking demolished items. I did think that wall joins had too many iterations and i'm starting to think that it was also changing the wall elements from existing that were in the same location. I almost need to lock off the existing model beyond just pinning it. That's why I thought about linking but I have too little experience to mess around without consulting AUGI. What are your thoughts? Can you replicate the problem or think of a way round?

[bregnier]

Barrie-

Sorry for the late reply. I've never had that problem with phasing before. In my experience objects can be modified by another object in a future phase, but not if it's been demolished. I've made modular buildings where each module was a different phase and we never had problems with hosted objects or wall joins. This is kind of a crazy idea (and goes against standard practice) but does putting a "blank" phase in between existing and new construction help at all?

[barrie.sharp]

I did try that. I used a demolished phase which helped with a few other issues but it didn't stop the cross talk.

If you create blank a drawing and add two walls in the existing phase, goto new, demo and add a beam between them it will want to make them bearing. If you draw a new wall inline with an old one and drag the new one, they move together.

It seems to me that demolish doesn't change behaviour, just visibility. Pinning helps a little. It was usefull putting the existing model on it's own workset. When I got warnings, the objects would be prefixed with the workset which helped me to know if I could ignore it. I've had so much trouble that I have split the old from the new. I may link them but the existing is static so no point really. I have kept the party wall in the existing phase. Technically, this is a new build and I should have taken this approach from the start. It's all experience ;) I never had this problem before so I guess it was just the nature of this project.

[bregnier]

I'll learn from your experience - that's a pity, I've always pushed the phasing tool as a well implemented part of revit and it's sad to hear that it's got limitations.